GTS125 Workshop Manual

GTS125 Workshop Manual
SERVICE STATION MANUAL
664662 IT-664663 EN-664664 FR-664665 DE-664666
ES-664667 PT-664668 OL-664669 EL
Vespa GTS 125
SERVICE STATION
MANUAL
Vespa GTS 125
The descriptions and illustrations given in this publication are not binding. While the basic specifications
as described and illustrated in this manual remain unchanged, PIAGGIO-GILERA reserves the right, at
any time and without being required to update this publication beforehand, to make any changes to
components, parts or accessories, which it considers necessary to improve the product or which are
required for manufacturing or construction reasons.
Not all versions shown in this publication are available in all Countries. The availability of single versions
should be checked at the official Piaggio sales network.
"© Copyright 2007 - PIAGGIO & C. S.p.A. Pontedera. All rights reserved. Reproduction of this publication
in whole or in part is prohibited."
PIAGGIO & C. S.p.A. - After-Sales
V.le Rinaldo Piaggio, 23 - 56025 PONTEDERA (Pi)
SERVICE STATION MANUAL
Vespa GTS 125
This service station manual has been drawn up by Piaggio & C. Spa to be used by the workshops of
Piaggio-Gilera dealers. It is assumed that the user of this manual for maintaining and repairing Piaggio
vehicles has a basic knowledge of mechanical principles and vehicle repair technique procedures. Any
significant changes to vehicle characteristics or to specific repair operations will be communicated by
updates to this manual. Nevertheless, no mounting work can be satisfactory if the necessary equipment
and tools are unavailable. It is therefore advisable to read the sections of this manual concerning special
tools, along with the special tool catalogue.
N.B. Provides key information to make the procedure easier to understand and carry out.
CAUTION Refers to specific procedures to carry out for preventing damages to the vehicle.
WARNING Refers to specific procedures to carry out to prevent injuries to the repairer.
Personal safety Failure to completely observe these instructions will result in serious risk of personal
injury.
Safeguarding the environment Sections marked with this symbol indicate the correct use of the vehicle
to prevent damaging the environment.
Vehicle intactness The incomplete or non-observance of these regulations leads to the risk of serious
damage to the vehicle and sometimes even the invalidity of the guarantee.
INDEX OF TOPICS
CHARACTERISTICS
CHAR
TOOLING
TOOL
MAINTENANCE
MAIN
TROUBLESHOOTING
TROUBL
ELECTRICAL SYSTEM
ELE SYS
ENGINE FROM VEHICLE
ENG VE
ENGINE
ENG
SUSPENSIONS
SUSP
BRAKING SYSTEM
BRAK SYS
COOLING SYSTEM
COOL SYS
CHASSIS
PRE-DELIVERY
TIME
CHAS
PRE DE
TIME
INDEX OF TOPICS
CHARACTERISTICS
CHAR
Characteristics
Vespa GTS 125
This section describes the general specifications of the vehicle.
Rules
This section describes general safety rules for any maintenance operations performed on the vehicle.
Safety rules
- If work can only be done on the vehicle with the engine running, make sure that the premises are wellventilated, using special extractors if necessary; never let the engine run in an enclosed area. Exhaust
fumes are toxic.
- The battery electrolyte contains sulphuric acid. Protect your eyes, clothes and skin. Sulphuric acid is
highly corrosive; in the event of contact with your eyes or skin, rinse thoroughly with abundant water
and seek immediate medical attention.
- The battery produces hydrogen, a gas that can be highly explosive. Do not smoke and avoid sparks
or flames near the battery, especially when charging it.
- Fuel is highly flammable and it can be explosive given some conditions. Do not smoke in the working
area, and avoid open flames or sparks.
- Clean the brake pads in a well-ventilated area, directing the jet of compressed air in such a way that
you do not breathe in the dust produced by the wear of the friction material. Even though the latter
contains no asbestos, inhaling dust is harmful.
Maintenance rules
- Use original PIAGGIO spare parts and lubricants recommended by the Manufacturer. Non-original or
non-conforming spares may damage the vehicle.
- Use only the appropriate tools designed for this vehicle.
- Always use new gaskets, sealing rings and split pins upon refitting.
- After removal, clean the components using non-flammable or low flash-point solvent. Lubricate all the
work surfaces except the tapered couplings before refitting.
- After refitting, make sure that all the components have been installed correctly and work properly.
- For removal, overhaul and refit operations use only tools with metric measures. Metric bolts, nuts and
screws are not interchangeable with coupling members with English measurement. Using unsuitable
coupling members and tools may damage the scooter.
- When carrying out maintenance operations on the vehicle that involve the electrical system, make
sure the electric connections have been made properly, particularly the ground and battery connections.
CHAR - 2
Vespa GTS 125
Characteristics
Vehicle identification
Chassis prefix: ZAPM313000000 ÷ 1001
Engine prefix: M315M1001
Dimensions and mass
WEIGHTS AND DIMENSIONS
Specification
Total kerb weight
Width (to hand grips)
Length
Wheelbase
Height
Saddle height
Desc./Quantity
145 ± 5 kg
755 mm
1940 mm
1395 mm
1180 mm
800 mm
CHAR - 3
Vespa GTS 125
Characteristics
Engine
ENGINE
Specification
Type
Cubic capacity
Bore x stroke
Compression ratio
Engine idle speed
Timing system
Valve clearance
MAX. power
MAX torque
Lubrication
Lubrication pressure
Minimum lubrication pressure (90° C)
Fuel supply
Cooling
Fuel
CHAR - 4
Desc./Quantity
Single-cylinder, 4-stroke
124 cm³
57.0 x 48.6 mm
12 ± 0.5: 1
1650 ± 100 rpm
4 valves, single overhead camshaft, chain-driven.
Inlet: 0.10 mm Outlet: 0.15 mm
10.5 kW at 9,500 rpm
12 Nm at 8,000 rpm
Engine lubrication with lobe pump (inside crankcase) controlled by a chain with double filter: mesh
and paper.
3 ÷ 4 bar
0.6 ÷ 1.2 bar
KEIHIN CVEK 30 carburettor and electrical fuel
pump.
Forced coolant circulation system.
Unleaded petrol (95 RON)
Vespa GTS 125
Characteristics
Transmission
TRANSMISSION
Specification
Transmission
Desc./Quantity
Automatic expandable pulley variator with torque
server, V belt, dry self-ventilating automatic centrifugal clutch and transmission housing with
forced air circulation.
Gear reduction unit in oil bath.
Final reduction
Capacities
CAPACITY
Specification
Engine oil
Transmission oil
Cooling system fluid
Fuel tank (reserve)
Desc./Quantity
1.10 l
150 cm³
~2l
~ 10 l (2 l)
Electrical system
ELECTRICAL SYSTEM
Specification
Start-up
Ignition
Ignition advance
Spark plug
Alternative spark plug
Battery
Desc./Quantity
Electric
Capacitive discharge ignition, with variable advance and separate HV coil.
10° at 2.000 rpm - 29° at 6.750 rpm
CHAMPION RG4HC
NGK CR8EB
Sealed, 12 V / 10 Ah
Frame and suspensions
FRAME AND SUSPENSIONS
Specification
Chassis
FRONT SUSPENSION
Front suspension travel
Rear suspension
Rear suspension travel
Desc./Quantity
Tubular and sheet steel.
Single arm with helicoidal spring and single double-acting hydraulic shock absorber.
- mm
Two double-acting shock absorbers, adjustable to
4 positions at preloading.
- mm
CHAR - 5
Vespa GTS 125
Characteristics
Brakes
BRAKES
Specification
Front brake
Desc./Quantity
Ø 220 disc brake with hydraulic control activated
by handlebar right lever.
Ø 200 mm disc brake with hydraulic control activated by handlebar left lever.
Rear brake
Wheels and tyres
WHEELS AND TYRES
Specification
Wheel rim type
Front rim
Rear rim
Front tyre
Rear tyre
Front tyre pressure (with passenger)
Rear tyre pressure (with passenger)
Desc./Quantity
Light alloy rims.
12'' x 3.00
12'' x 3.00
120/70 - 12'' 51P Tubeless
130/70 - 12'' 62P Tubeless
1.8 bar (-)
2.2 bar (-)
N.B.
CHECK AND ADJUST TYRE PRESSURE WITH TYRES AT AMBIENT TEMPERATURE. REGULATE PRESSURE ACCORDING TO THE WEIGHT OF THE RIDER AND ACCESSORIES
Carburettor
125cc Version
Kehin
CARBURETTOR KEIHIN
Specification
Depression carburettor
Body stamping
CUT-OFF device
Max. jet
Minimum jet
Max. air jet
Minimum air jet
Throttle valve spring
Minimum mixture set screw initial opening
Tapered pin
Diffuser nozzle
Starter air jet
Starter jet
Starter device resistance
Venturi diffuser
Throttle valve
N.B.
CHAR - 6
Desc./Quantity
CVEK-30
CVEK
Not present
108
38
70
130
100 ÷ 160 g
1±½
NDYB
Ø 5.0
Ø 1.5
42
~ 20 Ω
Ø 29 (47x30.9)
Ø 30.5
Vespa GTS 125
Characteristics
* THE IDENTIFICATION LETTER MAY VARY WITH EACH CARBURETTOR UPDATE.
Tightening Torques
STEERING ASSEMBLY
Name
Upper steering ring nut
Lower steering ring nut
Handlebar fixing screw
Torque in Nm
30 ÷ 40
8 ÷ 10
45 ÷ 50 (The two screws must be tightened to the
prescribed torque after having done so with the
rear wheel axle nut. Safety locks: see «Pre-delivery Operations» )
Fixing screws for handlebar control assembly U7 ÷ 10
bolts
FRAME ASSEMBLY
Name
Engine-swinging arm bolt
swinging arm bolt - body shell
Engine and vehicle side swinging arm junction bolt
Bolt of the Silent block support plate
Centre stand bolt
Side stand fixing bolt
Torque in Nm
64 - 72
76 ÷ 83
33 ÷ 41
42 ÷ 52
25 - 30
40 ÷ 45
FRONT SUSPENSION
Name
Screw fixing the shock absorber to the shock absorber - calliper attachment plate
Wheel axle nut
Wheel screw
Screw fixing rear mudguard to steering
Torque in Nm
20 ÷ 27
75 ÷ 90
20 ÷ 25
5 ÷ 6.5
FRONT BRAKE
Name
Brake fluid pump - hose fitting
Brake fluid hose-calliper fitting
Screw fixing calliper to the shock absorber - calliper plate attachment
Disc tightening screw
Oil bleed screw
Pad fastening pin
Brake pump reservoir screws
Torque in Nm
20 ÷ 25
20 ÷ 25
20 ÷ 25
6 (Apply LOCTITE 242 threadlock, medium
strength)
12 - 16
19.6 ÷ 24.5
15 ÷ 20
REAR SUSPENSION
Name
Retainer for left shock absorber to crankcase support plate
Shock absorber upper fitting
Shock absorber lower fitting
Rear wheel shaft
Screw fixing wheel to hub
Torque in Nm
20 ÷ 25
20 ÷ 25
33 ÷ 41
104 ÷ 126
20 ÷ 25
CHAR - 7
Vespa GTS 125
Characteristics
Name
Torque in Nm
Screws for muffler - shock absorber support arm 20 ÷ 25 (The two screws must be tightened to the
on engine
prescribed torque after having done so with the
rear wheel axle nut. Safety locks: see «Pre-delivery Operations» )
REAR BRAKE
Name
Brake fluid pump - hose fitting
Brake fluid pipe-calliper fitting
Rear disc tightening bolt
Oil bleed screw
Calliper to engine tightening screw
Brake pump reservoir screws
Calliper coupling screws
Torque in Nm
20 ÷ 25
20 ÷ 25
11 ÷ 13
12÷16
20 ÷ 25
15 ÷ 20
30 ÷ 33
MUFFLER
Name
Muffler heat guard clamping screw
Exhaust fumes inlet screw
Screw for fixing muffler to the support arm
Torque in Nm
5-6
13 ÷ 15
20 ÷ 25
LUBRICATION
Name
Hub oil drainage plug
Oil filter on crankcase fitting
Engine oil drainage plug/mesh filter
Oil filter
Oil pump cover screws
Screws fixing oil pump to the crankcase
Oil pump control crown screw
Oil pump cover plate screws
Oil sump screws
Minimum oil pressure sensor
Torque in Nm
15 ÷ 17
27 ÷ 33
24 ÷ 30
8 ÷ 10
7÷9
5-6
10 ÷ 14
4÷6
10 ÷ 14
12 ÷ 14
CYLINDER HEAD
Name
Spark plug
Head cover screws
Nuts for head fastening to the cylinder
Head fixing side screws
Starter ground screw
M5 side screw locking washers on camshaft
Tappet set screw lock nut
Inlet manifold screws
Timing chain tensioner slider screw
M6 central screw locking washers on camshaft
Timing chain tensioner support screw
Timing chain tensioner central screw
Camshaft retention plate screw
CHAR - 8
Torque in Nm
12 ÷ 14
6÷7
7± 1 + 180° (2x90°) (Fasten nuts in two crossed
passes) (Before fitting the nuts, lubricate them with
engine oil.)
11 ÷ 13
7 ÷ 8.5
7 ÷ 8.5
6÷8
11 ÷ 13
10 ÷ 14
11 ÷ 15
11 ÷ 13
5-6
4÷6
Vespa GTS 125
Characteristics
TRANSMISSION
Name
Belt support roller screw
Clutch assembly nut on driven pulley
Drive pulley nut
Transmission cover screws
Driven pulley shaft nut
Rear hub cap screws
Torque in Nm
11 ÷ 13
55 ÷ 60
75 ÷ 83
11 ÷ 13
54 ÷ 60
24 ÷ 27
FLYWHEEL
Name
Flywheel cover fixing screws
Stator assembly screws
Torque in Nm
5-6
3 - 4 (Apply LOCTITE 242 medium-strength
threadlock)
52 ÷ 58
3÷4
Flywheel nut
Pick-Up clamping screws
CRANKCASE AND CRANKSHAFT
Name
Internal engine crankcase bulkhead (transmission-side half shaft) screws
Engine-crankcase coupling screws
Starter motor screws
Crankcase timing cover screws
Torque in Nm
4÷6
11 ÷ 13
11 ÷ 13
3.5 - 4.5 (Apply LOCTITE 242 medium-strength
threadlock)
COOLING
Name
Water pump rotor cover
Screws of the water pump rotor driving link
Thermostat cover screws
Torque in Nm
3÷4
3÷4
3÷4
Overhaul data
Assembly clearances
CHAR - 9
Vespa GTS 125
Characteristics
Cylinder - piston assy.
COUPLING CATEGORIES
Name
Cylinder
Cylinder
Piston
Piston
Cylinder 1st Oversize
Cylinder 1st Oversize
Piston 1st Oversize
Piston 1st Oversize
Cylinder 2nd Oversize
Cylinder 2nd Oversize
Piston 2nd Oversize
Piston 2nd Oversize
Cylinder 3rd Oversize
Cylinder 3rd Oversize
Piston 3rd Oversize
CHAR - 10
Initials
A
B
C
D
A1
Cylinder
56.997 ÷ 57.004
57.004 ÷ 57.011
57.011 ÷ 57.018
57.018 ÷ 57.025
57.197 ÷ 57.204
Piston
56.945 ÷ 56.952
56.952 ÷ 56.959
56.959 ÷ 56.966
56.966 ÷ 56.973
57.145 ÷ 57.152
Play on fitting
0.045 - 0.059
0.045 - 0.059
0.045 - 0.059
0.045 - 0.059
0.045 - 0.059
B1
57.204 ÷ 57.211
57.152 ÷ 57.159
0.045 - 0.059
C1
57.211 ÷ 57.218
57.159 ÷ 57.166
0.045 - 0.059
D1
57.218 ÷ 57.225
57.166 ÷ 57.173
0.045 - 0.059
A2
57.397 ÷ 57.404
57.345 ÷ 57.352
0.045 - 0.059
B2
57.404 ÷ 57.411
57.352 ÷ 57.359
0.045 - 0.059
C2
57.411 ÷ 57.418
57.359 ÷ 57.366
0.045 - 0.059
D2
57.418 ÷ 57.425
57.366 ÷ 57.373
0.045 - 0.059
A3
57.597 ÷ 57.604
57.545 ÷ 57.552
0.045 - 0.059
B3
57.604 ÷ 57.611
57.552 ÷ 57.559
0.045 - 0.059
C3
57.611 ÷ 57.618
57.559 ÷ 57.566
0.045 - 0.059
Vespa GTS 125
Name
Piston 3rd Oversize
Characteristics
Initials
D3
Cylinder
57.618 ÷ 57.625
Piston
57.566 ÷ 57.573
Play on fitting
0.045 - 0.059
Piston rings
ENGINE SEALING RINGS
Name
Compression ring
Oil scraper ring
Oil scraper ring
Description
Dimensions
57 x 1
57 x 1
57 x 2.5
Initials
A
A
A
Quantity
0.15 ÷ 0.30
0.10 ÷ 0.30
0.15 ÷ 0.35
ENGINE SEALING RINGS (1ST OVERSIZE)
Name
Compression ring
1st oversize
Oil scraper ring 1st
Oversize
Oil scraper ring 1st
Oversize
Description
Dimensions
57.2 x 1
Initials
A
Quantity
0.15 ÷ 0.30
57.2 x 1
A
0.10 ÷ 0.30
57.2 x 2.5
A
0.15 ÷ 0.35
ENGINE SEALING RINGS (2ND OVERSIZE)
Name
Compression ring
2nd Oversize
Oil scraper ring
2nd Oversize
Oil scraper ring
2nd Oversize
Description
Dimensions
57.4 x 1
Initials
A
Quantity
0.15 ÷ 0.30
57.4 x 1
A
0.10 ÷ 0.30
57.4 x 2.5
A
0.15 ÷ 0.35
ENGINE SEALING RINGS (3RD OVERSIZE)
Name
Compression ring
3rd Oversize
Oil scraper ring 3rd
Oversize
Oil scraper ring 3rd
Oversize
Description
Dimensions
57.6 x 1
Initials
A
57.6 x 1
A
57.6 x 2.5
A
Quantity
0.15 ÷ 0.30
0.15 ÷ 0.35
CHAR - 11
Characteristics
Crankcase - crankshaft - connecting rod
Fitting clearances
Crankshaft/crankcase axial clearance (H):
0.15 ÷ 0.40 mm (when cold)
CHAR - 12
Vespa GTS 125
Vespa GTS 125
Characteristics
CRANKSHAFT/ CRANKCASE AXIAL CLEARANCE
Name
Half-shaft, transmission side
Flywheel-side halfshaft
Connecting rod
Spacer tool
Description
Dimensions
16.6 +0-0.05
Initials
A
Quantity
D = 0.20 - 0.50
16.6 +0-0.05
B
D = 0.20 - 0.50
18 -0.10 -0.15
51.4 +0.05
C
E
D = 0.20 - 0.50
D = 0.20 - 0.50
Initials
Category B - blue
Quantity
1.973 ÷ 1.976
Category C - yellow
Category E - green
1.976 ÷ 1.979
CRANKSHAFT HALF-BEARINGS
Name
Crankshaft halfbearing
Crankshaft halfbearing
Crankshaft halfbearing
Description
Dimensions
1.979 ÷ 1.982
CRANKCASE - CRANKSHAFT COUPLINGS
Name
Crankshaft category 1 - Crankcase
category 1
Crankshaft category 1 - Crankcase
category 2
Crankshaft category 2 - Crankcase
category 1
Crankshaft category 2 - Crankcase
category 2
Description
Dimensions
Initials
E-E
Quantity
C-C
C-C
B-B
CRANKSHAFT - CRANKCASE
Name
Crankshaft
Crankshaft
Crankcase
Crankcase
Description
Dimensions
Initials
Category 1
Category 2
Category 1
Category 2
Quantity
28.998 ÷ 29.004
29.004 ÷ 29.010
32.959 ÷ 32.965
32.953 ÷ 32.959
CHAR - 13
Vespa GTS 125
Characteristics
Slot packing system
Characteristic
Compression ratio
12 ± 0.5: 1
Measurement "A" to be taken is a value of piston protrusion. It indicates by how much the plane formed
by the piston crown protrudes from the plane formed by the upper part of the cylinder. The further the
piston protrudes from the cylinder, the bigger the base gasket to be used (to recover the compression
ratio) and vice versa.
N.B.
DISTANCE "A" MUST BE MEASURED WITHOUT ANY GASKET FITTED BETWEEN CRANKCASE
AND CYLINDER
SHIMMING
Name
Shimming
Shimming
Measure A
2.2 ÷ 2.4
2.4 ÷ 2.6
Thickness
0.4 ± 0.05
0.6 ± 0.05
Products
RECOMMENDED PRODUCTS TABLE
Product
AGIP ROTRA 80W-90
AGIP CITY HI TEC 4T
AGIP FILTER OIL
AGIP GP 330
AGIP CITY HI TEC 4T
AGIP BRAKE 4
SPECIAL AGIP PERMANENT
fluid
CHAR - 14
Description
Rear hub oil
Specifications
SAE 80W/90 Oil that exceeds the
requirements of API GL3 specifications
Oil to lubricate flexible transmisOil for 4-stroke engines
sions (throttle control)
Oil for air filter sponge
Mineral oil with specific additives
for increased adhesiveness
Calcium complex soap-based
Grease (brake control levers,
grease with NLGI 2; ISO-Lthrottle grip)
XBCIB2
Engine oil
SAE 5W-40, API SL, ACEA A3,
JASO MA Synthetic oil
Brake fluid
FMVSS DOT4 Synthetic fluid
coolant
Monoethylene glycol-based antifreeze fluid, CUNA NC 956-16
INDEX OF TOPICS
TOOLING
TOOL
Vespa GTS 125
Tooling
APPROPRIATE TOOLS
TOOL - 2
Stores code
001330Y
Description
Tool for fitting steering seats
001467Y009
Driver for OD 42 mm bearings
001467Y017
Bell for bearings, outside Ø 39
mm
001467Y014
Pliers to extract ø 15-mm bearings
005095Y
Engine support
002465Y
Pliers for circlips
006029Y
Punch for fitting fifth wheel seat
on steering tube
Vespa GTS 125
Tooling
Stores code
008564Y
Description
Flywheel extractor
020004Y
Punch for removing fifth wheels
from headstock
020021Y
Front suspension service tool
020036Y
Punch
020037Y
Punch
TOOL - 3
Vespa GTS 125
Tooling
TOOL - 4
Stores code
020038Y
Description
Punch
020055Y
Wrench for steering tube ring nut
020074Y
Support base for checking crankshaft alignment
020150Y
Air heater support
020151Y
Air heater
020193Y
Oil pressure gauge
020262Y
Crankcase splitting strip
Vespa GTS 125
Tooling
Stores code
020263Y
Description
Sheath for driven pulley fitting
020287Y
Clamp to assemble piston on cylinder
020306Y
Punch for assembling valve seal
rings
020319Y
Immobilizer check tester
020329Y
MityVac vacuum-operated pump
020330Y
Stroboscopic light for timing control
TOOL - 5
Vespa GTS 125
Tooling
TOOL - 6
Stores code
020331Y
Description
Digital multimeter
020332Y
Digital rev counter
020333Y
Single battery charger
020334Y
Multiple battery charger
Vespa GTS 125
Tooling
Stores code
020335Y
Description
Magnetic support for dial gauge
020357Y
020359Y
32 x 35 mm adaptor
42x47-mm adaptor
020360Y
Adaptor 52 x 55 mm
020363Y
20 mm guide
020364Y
25-mm guide
TOOL - 7
Vespa GTS 125
Tooling
TOOL - 8
Stores code
020365Y
Description
22 mm guide
020368Y
driving pulley lock wrench
020375Y
Adaptor 28 x 30 mm
020376Y
Adaptor handle
020382Y
Valve cotters equipped with part
012 removal tool
020382Y011
adapter for valve removal tool
Vespa GTS 125
Tooling
Stores code
020393Y
Description
Piston fitting band
020409Y
Multimeter adaptor - Peak voltage detection
020412Y
15 mm guide
020414Y
28-mm guide
020423Y
driven pulley lock wrench
TOOL - 9
Vespa GTS 125
Tooling
TOOL - 10
Stores code
020424Y
Description
Driven pulley roller casing fitting
punch
020425Y
Punch for flywheel-side oil seal
020426Y
Piston fitting fork
020430Y
Pin lock fitting tool
020431Y
Valve oil seal extractor
020434Y
Oil pressure control fitting
Vespa GTS 125
Tooling
Stores code
020439Y
Description
17 mm guide
020440Y
Water pump service tool
020441Y
26 x 28 mm adaptor
020442Y
Pulley lock wrench
020444Y
Tool for fitting/ removing the driven pulley clutch
TOOL - 11
Vespa GTS 125
Tooling
TOOL - 12
Stores code
020455Y
Description
10-mm guide
020456Y
020477Y
Ø 24 mm adaptor
Adaptor 37 mm
020483Y
30 mm guide
020489Y
Hub cover support stud bolt set
020565Y
Flywheel lock calliper spanner
INDEX OF TOPICS
MAINTENANCE
MAIN
Vespa GTS 125
Maintenance
Maintenance chart
EVERY 2 YEARS
Action
Coolant - change
Brake fluid - change
Secondary air filter (external / internal) - Clean
AFTER 1000 KM
80'
Action
Engine oil - replacement
Hub oil - change
Engine oil - change
Idle speed (*) - adjustment
Throttle lever - adjustment
Steering - adjustment
Brake control levers - greasing
Brake pads - check condition and wear
Brake fluid level - check
Safety locks - check
Electrical system and battery - check
Tyre pressure and wear - check
Vehicle and brake test - road test
(*) See instructions in «Idle speed adjustment» section
EVERY 3,000 KM
10'
Action
Engine oil - level check/ top-up
AFTER 6000 KM
Action
Engine oil - replacement
Hub oil level - check
Spark plug/ electrode gap - check
Air filter - clean
Engine oil - change
valve clearance - check
Variable speed rollers - check or replacement
Driving belt - check
Coolant level - check
Brake pads - check condition and wear
Brake fluid level - check
Electrical system and battery - check
Tyre pressure and wear - check
Vehicle and brake test - road test
AFTER 12,000 KM; 60,000 KM
130'
MAIN - 2
Vespa GTS 125
Maintenance
Action
Engine oil - replacement
Hub oil level - check
Air filter - clean
Engine oil - change
Spark plug - replacement
Idle speed (*) - adjustment
Throttle lever - adjustment
Driven pulley roller casing - Greasing
Driving belt - replacement
Sliding blocks / variable speed rollers - check
Coolant level - check
Steering - adjustment
Brake control levers - greasing
Brake pads - check condition and wear
Brake fluid level - check
Transmission elements - lubrication
Safety locks - check
Suspensions - check
Electrical system and battery - check
Headlight - adjustment
Tyre pressure and wear - check
Vehicle and brake test - road test
(*) See instructions in the «Idle speed adjustment» section
AT 18000 KM AND AT 54000 KM
100'
Action
Engine oil - replacement
Hub oil level - check
Spark plug/ electrode gap - check
Air filter - clean
Engine oil - change
Variable speed rollers - check or replacement
Driving belt - check
Coolant level - check
Radiator - external cleaning/ check
Brake pads - check condition and wear
Brake fluid level - check
Electrical system and battery - check
Tyre pressure and wear - check
Vehicle and brake test - road test
AT 24000 KM AND AT 48000 KM
Action
Engine oil - replacement
Hub oil - change
Air filter - clean
Engine oil - change
Spark plug - replacement
valve clearance - check
Idle speed (*) - adjustment
Throttle lever - adjustment
Variable speed rollers - check or replacement
MAIN - 3
Vespa GTS 125
Maintenance
Action
Driving belt - replacement
Coolant level - check
Steering - adjustment
Brake control levers - greasing
Brake pads - check condition and wear
Brake fluid level - check
Transmission elements - lubrication
Safety locks - check
Suspensions - check
Electrical system and battery - check
Headlight - adjustment
Driven pulley roller casing - Greasing
Tyre pressure and wear - check
Vehicle and brake test - road test
(*) See instructions in «Idle speed adjustment» section
AT 30000 KM, AT 42000 KM AND AT 66000 KM
Action
Hub oil level - check
Spark plug/ electrode gap - check
Air filter - clean
Variable speed rollers - check or replacement
Driving belt - check
Coolant level - check
Brake pads - check condition and wear
Brake fluid level - check
Electrical system and battery - check
Tyre pressure and wear - check
Vehicle and brake test - road test
Engine oil - replacement
Oil filter -Replacement
AFTER 36000 KM
Action
Engine oil - replacement
Hub oil level - check
Air filter - clean
Engine oil - change
Spark plug - replacement
Idle speed (*) - adjustment
Throttle lever - adjustment
Variable speed rollers - check or replacement
Driving belt - replacement
Coolant level - check
Radiator - external cleaning/ check
Steering - adjustment
Brake control levers - greasing
Brake pads - check condition and wear
Brake fluid hoses - replacement
Brake fluid level - check
Transmission elements - lubrication
Safety locks - check
Suspensions - check
MAIN - 4
Vespa GTS 125
Maintenance
Action
Electrical system and battery - check
Headlight - adjustment
Driven pulley roller casing - Greasing
Tyre pressure and wear - check
Vehicle and brake test - road test
(*) See instructions in «Idle speed adjustment» section
AFTER 72000 KM
Action
Engine oil - replacement
Hub oil - change
Spark plug / electrode gap - check / replacement
Air filter - clean
Engine oil - change
valve clearance - check
Idle speed (*) - adjustment
Throttle lever - adjustment
Variable speed rollers - check or replacement
Driving belt - replacement
Coolant level - check
Radiator - external cleaning/ check
Steering - adjustment
Brake control levers - greasing
Brake pads - check condition and wear
Brake fluid hoses - replacement
Brake fluid level - check
Transmission elements - lubrication
Safety locks - check
Suspensions - check
Electrical system and battery - check
Headlight - adjustment
Driven pulley roller casing - Greasing
Tyre pressure and wear - check
Vehicle and brake test - road test
(*) See instructions in «Idle speed adjustment» section
Carburettor
- Disassemble the carburettor in its parts, wash all of them with solvent, dry all body grooves with
compressed air to ensure adequate cleaning.
- Check carefully that the parts are in good condition.
- The throttle valve should move freely in the chamber. Replace it in case of excessive clearance due
to wear.
- If there are wear marks in the chamber causing inadequate tightness or a free valve slide (even if it
is new), replace the carburettor.
- It is advisable to replace the gaskets at every refit
WARNING
PETROL IS HIGHLY EXPLOSIVE ALWAYS REPLACE THE GASKETS TO AVOID PETROL LEAKS
MAIN - 5
Maintenance
Checking the spark advance
- To check ignition advance, use the stroboscopic
light with induction pincers connected to the spark
plug power wire.
- Connect the induction pincers being careful to
respect the proper polarity (the arrow stamped on
the pincers must be pointing at the spark plug).
- Place the light selector in central position (1 spark
= 1 crankshaft revolution as in 2 T engines).
- Start the engine and check that the light works
properly and the rpm indicator can read also the
high rpm (e.g. 8000 rpm).
- If flash unsteadiness or revolution reading error
is detected (e.g. half values), increase the resistive
load on the spark plug power line (10 ÷ 15 KΩ in
series to AT cable).
- Remove the plastic cover from the slot on the flywheel cover.
- Operating on the flash corrector displacement of
the bulb, make the reference on the flywheel cover
coincide with level on the water pump drive. Read
the advance degrees indicated by the stroboscopic light.
- Check that the advance degrees corresponds
with the rotation rpm as indicated in the table.
- If there are anomalies, check the Pick-Up and the
control unit power supply (positive-negative), replace the control unit if necessary.
- The brand new control unit prevents that the engine rotation exceeds 2000 rpm.
- The programmed control unit allows the engine
to rotate within the prescribed limits.
Characteristic
Ignition advance
10° at 2.000 rpm - 29° at 6.750 rpm
MAIN - 6
Vespa GTS 125
Vespa GTS 125
Maintenance
Spark advance variation
IGNITION ADVANCE VARIATION
Specification
Operation threshold
Reactivation threshold
Spark elimination
Desc./Quantity
First threshold : 10700 ±50
Second threshold : 11000 ±50
First threshold : 10600±50
Second threshold : 10900±50
First threshold : 1 spark on 7
Second threshold : 2 sparks on 3
Spark plug
- Rest the scooter on its stand
- Open the saddle and take out the helmet compartment
- Disconnect spark plug HV wire hood;
- Unscrew the spark plug using the wrench supplied;
- Check the conditions of the spark plug, make
sure the insulation is intact, that the electrodes are
MAIN - 7
Maintenance
not excessively worn or grimy, the conditions of the
washer, and measure the distance between the
electrodes using the appropriate feeler gauge.
-Adjust the distance if necessary by bending the
side electrode very carefully. In case of anomaly
(as described before) replace the spark plug with
another of the recommended type;
- Fit the spark plug with the correct inclination and
manually screw it all the way down, then use the
special spanner to tighten it.
- Insert the cap onto the spark plug and proceed
with the reassembly operations.
CAUTION
THE SPARK PLUG MUST BE REMOVED WHEN
THE MOTOR IS COLD. THE SPARK PLUG
MUST BE REPLACED EVERY 12,000 KM. THE
USE OF NON CONFORMING IGNITION CONTROL UNITS OR SPARK PLUGS OTHER THAN
THOSE PRESCRIBED CAN SERIOUSLY DAMAGE THE ENGINE.
Characteristic
Spark plug
Champion RG 4 HC
Alternative spark plug
NGK CR8EB
Electrode gap
0.7-0.8 mm
Locking torques (N*m)
Spark plug 12 ÷ 14
Hub oil
MAIN - 8
Vespa GTS 125
Vespa GTS 125
Maintenance
Check
-Stand the vehicle on its centre stand on flat
ground;
-Remove the oil dipstick "A", dry it with a clean
cloth and put it back into its hole tightening it
completely;
-Take out the dipstick checking that the oil level
reaches the dipstick lower notch; if the level is under the MAX. mark, it needs to be filled with the
right amount of hub oil.
-Screw up the oil dipstick again and make sure it
is locked properly into place.
Replacement
-Remove the oil cap «A».
- Unscrew the oil drainage cap "B" and drain out
all the oil.
- Screw in the drainage cap again and fill the hub
with the prescribed oil.
Recommended products
AGIP ROTRA 80W-90 Rear hub oil
SAE 80W/90 Oil that exceeds the requirements of
API GL3 specifications
Characteristic
Rear hub oil
Capacity ~ 150 cm³
Locking torques (N*m)
Hub oil drainage screw 15 ÷ 17 Nm
MAIN - 9
Maintenance
Vespa GTS 125
Air filter
Proceed as follows:
1. unscrew the fixing screw «A».
2. unscrew the nut «B» under the body.
3. remove the left side fairing.
4. remove the helmet compartment;
5. unscrew the fixing screws «C» that can be
reached once the helmet compartment has been
removed;
6. Unscrew the screws «D» and remove the air filter cover.
Remove the filtering element and clean it with water and shampoo; then dry it with a clean cloth and
short blasts of compressed air. Finally, immerse it
in a mixture of 50% oil of the recommended type
and 50% petrol. Then gently squeeze the filter element between your hands, allow it to drip and
then refit it. Oil or water deposits in the filter housing can be cleaned off by removing the two rubber
caps «E».
CAUTION
IF THE VEHICLE IS USED ON DUSTY ROADS
IT IS NECESSARY TO CARRY OUT MAINTENANCE CONTROLS OF THE AIR FILTER TO
AVOID DAMAGING THE ENGINE.
Recommended products
AGIP FILTER OIL Oil for air filter sponge
Mineral oil with specific additives for increased adhesiveness
Engine oil
In 4T engines, the engine oil is used to lubricate the distribution elements, the bench bearings and the
thermal group. An insufficient quantity of oil can cause serious damage to the engine.
MAIN - 10
Vespa GTS 125
Maintenance
In all 4T engines, the deterioration of the oil characteristics, or a certain consumption should be considered normal, especially if during the run-in period. Consumption levels in particular can be influenced
by the conditions of use (e.g.: oil consumption increases when driving at "full throttle".
Replacement
Replace oil and filter as indicated in the scheduled
maintenance table. The engine must be drained
by running off the oil from drainage cap "B" of the
flywheel side mesh pre-filter; furthermore to facilitate oil drainage, loosen the cap/dipstick "A". Once
all the oil has drained through the drainage hole,
unscrew the oil cartridge filter "C" and remove it.
Make sure the pre-filter and discharge tap O-rings
are in good condition.
Lubricate them and refit the mesh filter and oil
drainage plug, screwing them up to the specified
torque.
Refit the new cartridge filter being careful to lubricate the O-ring before fitting it.
Change the engine oil.
Since a certain quantity of oil still remains in the
circuit, oil must be filled from cap "A". Then start
up the scooter, leave it running for a few minutes
and switch it off: after five minutes check the level
and if necessary top up without exceeding the
MAX level. The cartridge filter must be replaced
every time the oil is changed. Use new oil of the
recommended type for topping up and changing
purposes.
N.B.
THE ENGINE MUST BE HOT WHEN THE OIL IS
CHANGED.
Recommended products
AGIP CITY HI TEC 4T Engine oil
SAE 5W-40 Synthetic oil that exceed the requirements of API SL, ACEA A3, JASO MA specifications
Characteristic
MAIN - 11
Maintenance
Vespa GTS 125
Engine oil top-up
600 ÷ 650 cc
Check
This operation must be carried out with the engine cold and following the procedure below:
1. Place the vehicle on its centre stand and on flat ground.
2. Undo cap/dipstick "A", dry it off with a clean cloth and replace it, screwing down completely.
3. Remove the cap/dipstick again and check that the level is between the min and max. marks; top
up if necessary.
The MAX level mark indicates a quantity of around 1100 cc of oil in the engine. If the check is carried
out after the vehicle has been used, and therefore with a hot engine, the level line will be lower; in order
to carry out a correct check it is necessary to wait at least 10 minutes after the engine has been stopped,
so as to get the correct level.
Oil top up
The oil should be topped up after having checked
the level and in any case by adding oil without
ever exceeding the MAX. level.
The restoration level between the MIN and MAX
levels implies a quantity of oil of approx. 400 cc.
Oil pressure warning light
The vehicle is equipped with a warning light on the instrument panel that lights up when the key is turned
to the «ON» position. However, this light should switch off once the engine has been started.
If the light turns on during braking, at idling speed or while turning a corner, it is necessary to
check the oil level and the lubrication system.
MAIN - 12
Vespa GTS 125
Maintenance
Checking the ignition timing
-Remove the 4 fixing screws and move away from
the engine the flywheel cover equipped with a water pump and cooling manifolds.
-Rotate the flywheel until the reference matches
the crankcase operation end as shown in the figure
(TDC). Make sure that the 4V reference point on
the camshaft command pulley is aligned with the
reference point on the head as shown in the second figure. If the reference mark is opposite the
indicator on the head, make the crankshaft turn
once more.
-The TDC reference mark is repeated also between the flywheel cooling fan and the flywheel
cover.
To use this reference mark, remove the spark plug
and turn the engine in the sense opposite to the
normal direction using a calliper spanner applied
to the camshaft command pulley casing.
N.B.
TIME THE TIMING SYSTEM UNIT IF IT IS NOT
IN PHASE.
Cooling system
Introduction of the engine coolant.
Check coolant level when the engine is cold as indicated in the scheduled maintenance table for
kilometres covered, following the steps below:
Place the scooter on its centre stand and on flat
ground.
- Undo the screw shown in the figure and remove
the expansion tank cap on RHS.
- Top up if the fluid level is near or below the MIN
level edge. The liquid level must always be between the MIN and MAX level.
-The coolant consists of an ethylene glycol and
corrosion inhibitor based 50% de-ionised waterantifreeze solution mix.
MAIN - 13
Maintenance
CAUTION
DO NOT EXCEED THE MAX. LEVEL WHEN
FILLING SO AS TO AVOID THE COOLANT ESCAPING FROM THE EXPANSION TANK WHEN
THE vehicle IS IN USE.
Braking system
Level check
The brake fluid tanks for the front and rear brakes
are located on the pumps under the handlebar
cover. Proceed as follows:
- Remove the brake pump cover
- Rest the vehicle on its centre stand with the handlebars perfectly horizontal;
- Check the fluid level through the sight glass as
shown in the figure. A certain lowering of the level
is caused by wear on the pads.
MAIN - 14
Vespa GTS 125
Vespa GTS 125
Maintenance
Top-up
- Position the vehicle on a flat surface and on the
centre stand
- Remove the brake pump cover as indicated in the
photo
Check the brake fluid level through the sight glass
on the pump as shown in the photograph
- If the level is below the minimum, fill using the two
screws shown in the figure
- Remove the gasket and fill with DOT 4 until the spyglass is completely covered
For refitting purposes carry out the operations in
the reverse order from the removal operation and
respect the tightening torque of the tank cover
screws.
CAUTION
MAKE SURE THE BRAKE FLUID DOES NOT
GET INTO YOUR EYES OR ON YOUR SKIN OR
CLOTHES. IF THIS HAPPENS ACCIDENTALLY,
WASH WITH WATER.
CAUTION
THE BRAKING CIRCUIT FLUID IS HIGHLY
CORROSIVE. THEREFORE, WHEN TOPPING
IT UP, AVOID LETTING IT COME INTO CONTACT WITH THE PAINTED PARTS OF THE VEHICLE. THE BRAKING CIRCUIT FLUID IS HYGROSCOPIC, WHICH MEANS THAT IT
ABSORBS MOISTURE FROM THE SURROUNDING AIR. IF MOISTURE CONTAINED IN
THE BRAKE FLUID EXCEEDS A CERTAIN
MAIN - 15
Maintenance
VALUE, THIS WILL RESULT IN INEFFICIENT
BRAKING.
CAUTION
NEVER USE BRAKE FLUID COMING FROM
OPEN OR PARTIALLY USED CONTAINERS.
UNDER NORMAL WEATHER CONDITIONS,
BRAKE FLUID MUST BE CHANGED AS INDICATED IN THE SCHEDULED MAINTENANCE
TABLE.
Locking torques (N*m)
Brake pump reservoir screws 15 ÷ 20
Headlight adjustment
- Position the unloaded vehicle, in running conditions and with the tyres inflated to the prescribed
pressure, onto a flat surface 10 m away from a
white screen in a half-lit room, and make sure the
vehicle longitudinal axis is perpendicular to the
screen.
- Draw a horizontal line on the screen at a height
of 67 ÷ 70 cm from the ground.
- Remove the front radiator grille working on the
screw indicated in the photograph
- Switch on the low-beam headlight and check that
the horizontal borderline between the projected
light beam and the dark area is not higher than the
horizontal line drawn on the screen. To remove the
headlight, act on the screw indicated in the figure.
MAIN - 16
Vespa GTS 125
Vespa GTS 125
Maintenance
SAS filters inspection and cleaning
the SAS for leader engines 125 cm³ - 200 cm³ Euro
2 operates in a similar manner to the SAS for 2T
engines.
The differences are the following:
instead of entering through the muffler as for 2T
engine, the secondary air enters directly in the discharge pipe on the head.
The 2T reed valve has a diaphragm. The unit, indicated by an arrow in the figure, has a cut-off
connected to the depression intake on the inlet
manifold that cuts the air inlet in deceleration, to
avoid explosions in the muffler.
System description:
Air is drawn through the opening "A", goes through
the first filter and is channelled through the opening "B"
Air gets to the second filter "B" through the opening
indicated in the figure.
Now, the filtered air enters the diaphragm device,
and then is channelled to the head.
MAIN - 17
Maintenance
The air passes through a rigid pipe connected to
the head and reaches a discharge joint in order to
supply oxygen to the unburned gases before the
catalytic converter, thus favouring an improved reaction of the catalytic converter.
- Remove the muffler.
- Remove the right-hand side fairing
- Remove the coolant inlet and outlet couplings
from the pump cover. Then, drain the system
- Remove the upper clamp of the SAS valve connection coupling to the drainage as indicated in the
photograph
MAIN - 18
Vespa GTS 125
Vespa GTS 125
Maintenance
- Remove the 2 fixing screws, the gasket and the
pipe connecting the SAS valve to the head. Then
remove the pipe.
- Release the electrical cable from the flywheel
cover clamp as indicated in the photograph
- Disconnect the depression pipe from the SAS
valve
MAIN - 19
Maintenance
- Remove the pump support bracket and fuel filter.
- Remove the flywheel cover together with the SAS
valve acting on the 4 hexagonal-head screws as
indicated in the photograph
- Remove the SAS valve two fixing screws and remove the SAS valve together with the O-ring from
the support
- Remove the plastic support together with the
gasket
MAIN - 20
Vespa GTS 125
Vespa GTS 125
Maintenance
- Check that the SAS valve plastic support is not
dented or distorted
- Check that the gasket is in good conditions
- Carefully clean the inside and outside filters. Replace them if damaged or abnormally distorted.
- Make sure the coupling connecting the secondary air to the head is not dented, overheated or
distorted. If there is, replace it.
- Check that the metal pipe does not have any
dents
CAUTION
INADEQUATE TIGHTNESS BETWEEN THE
SAS VALVE AND ITS SUPPORT INCREASES
NOISE IN THE SAS SYSTEM.
To refit, follow the removal procedure in reverse order being careful to respect the direction of the rubber
coupling connecting the SAS valve and the discharge system
MAIN - 21
Maintenance
MAIN - 22
Vespa GTS 125
INDEX OF TOPICS
TROUBLESHOOTING
TROUBL
Vespa GTS 125
Troubleshooting
This section makes it possible to find what solutions to apply when troubleshooting.
For each breakdown, a list of the possible causes and respective interventions is given.
Engine
Poor performance
POOR PERFORMANCE
Possible Cause
Operation
The carburettor is dirty; fuel pump or vacuum valve Remove, wash with solvent and dry with comdamaged
pressed air or replace
Incorrect timing or worn timing system elements Time the system again or replace the worn parts
Muffler obstructed
Replace
Air filter blocked or dirty
Remove the sponge, wash with water and car
shampoo, then soak it in a mixture of 50% petrol
and 50% specific oil. Press with your hand without
squeezing, allow it to drip dry and refit.
Automatic starter failure
Check: mechanical movement, electric connection and power supply, replace if required.
Oil level exceeds maximum
Check for causes and fill to reach the correct level
Lack of compression parts, cylinder and valves
Replace the worn parts
wear
Transmission belt worn
Replace
Inefficient automatic transmission
Check the rollers and the pulley movement, replace the damaged parts and lubricate the driven
pulley moveable guide with Montblanc Molybdenum Grease
Clutch slipping
Check the clutch system and/or the bell and replace if necessary
Carburettor nozzles clogged
Dismantle, wash with solvent and dry with compressed air
Rear wheel spins at idle
REAR WHEEL ROTATES WITH ENGINE AT IDLE
Possible Cause
Idling rpm too high
Clutch fault
Intake coupling cracked or clamps incorrectly
tightened
Operation
Adjust the engine idle speed
Check the springs / clutch masses
Replace the intake coupling and check the clamps
are tightened
Starting difficulties
DIFFICULTY STARTING UP
Possible Cause
Altered fuel characteristics
Rpm too low at start-up or engine and start-up
system damaged
TROUBL - 2
Operation
Drain off the fuel no longer up to standard; then,
refill
Check the starter motor, the system and the torque
limiter
Vespa GTS 125
Troubleshooting
Possible Cause
Incorrect valve sealing or valve adjustment
Operation
Inspect the head and/or restore the correct clearance
- Engine flooded.
Try starting-up with the throttle fully open. If the
engine fails to start, remove the spark plug, dry it
and before refitting, make the motor turn so as to
expel the fuel excess taking care to connect the
cap to the spark plug, and this in turn to the ground.
If the fuel tank is empty, refuel and start up.
Automatic starter failure
Check: mechanical movement, electric connection and fuel supply, replace if required.
Air filter blocked or dirty
Remove the sponge, wash with water and car
shampoo, then soak it in a mixture of 50% petrol
and 50% specific oil. Press with your hand without
squeezing, allow it to drip dry and refit.
Faulty spark plug or incorrect ignition advance Replace the spark plug or check the ignition circuit
components
The carburettor is dirty; fuel pump or vacuum valve Remove, wash with solvent and dry with comdamaged
pressed air or replace
Battery flat
Check the charge of the battery, if there are any
sulphur marks, replace and use the new battery
following the instructions shown in the chapter
Intake coupling cracked or clamps incorrectly
Replace the intake coupling and check the clamps
tightened
are tightened
Defective floating valve
Check the proper sliding of the float and the functioning of the valve
Carburettor nozzles clogged
Dismantle, wash with solvent and dry with compressed air
Excessive oil consumption/Exhaust smoke
EXCESSIVE CONSUMPTION
Possible Cause
Wrong valve adjustment
Overheated valves
Operation
Adjust the valve clearance properly
Remove the head and the valves, grind or replace
the valves
Misshapen/worn valve seats
Replace the head assembly
Worn cylinder, Worn or broken piston rings
Replace the piston cylinder assembly or piston
rings
Worn or broken piston rings or piston rings that Replace the piston cylinder unit or just the piston
have not been fitted properly
rings
Oil leaks from the couplings or from the gaskets Check and replace the gaskets or restore the coupling seal
Worn valve oil guard
Replace the valve oil guard
Worn valve guides
Check and replace the head unit if required
Insufficient lubrication pressure
POOR LUBRICATION PRESSURE
Possible Cause
By-Pass remains open
Operation
Check the By-Pass and replace if required. Carefully clean the By-Pass area.
TROUBL - 3
Vespa GTS 125
Troubleshooting
Possible Cause
Oil pump with excessive clearance
Oil filter too dirty
Oil level too low
Operation
Perform the dimensional checks on the oil pump
components
Replace the cartridge filter
Restore the level adding the recommended oil
type
Engine tends to cut-off at full throttle
THE MOTOR TENDS TO STOP AT MAXIMUM THROTTLE
Possible Cause
Level in tank too low
Tank breather hole obstructed
Fuel supply pipes choked or clogged
Maximum nozzle dirty - lean mixture
Water in the carburettor
Incorrect float level
Faulty fuel supply
Operation
Restore the level in the tank by bending on the float
the thrusting reed of the petrol inlet rod so as to
have the float parallel to the tank level with the
carburettor inverted.
Restore the proper tank aeration
Restore the adequate fuel supply
Wash the nozzle with solvent and dry with compressed air
Empty the tank through the appropriate bleed nipple.
Restore the level in the tank by bending on the float
the thrusting reed of the petrol inlet rod so as to
have the float parallel to the tank level with the
carburettor inverted.
Check or replace the fuel pump, and check the
vacuum intake and the pipe sealing
Engine tends to cut-off at idle
THE ENGINE TENDS TO STOP AT IDLE SPEED
Possible Cause
Air calibrated holes in carburettor blocked
Defective floating valve
Level in chamber too high
The starter remains on
Air filter blocked or dirty
Incorrect timing
Cut off device failure
Incorrect idle adjustment
TROUBL - 4
Operation
Dismantle, wash with solvent and dry with compressed air
Check the proper sliding of the float and the functioning of the valve
Restore the level of the float chamber bending on
the float the thrusting reed of the petrol inlet pin so
as to have the float parallel to the float chamber
level, with the carburettor inverted.
Check the electric connection, fuel supply and mechanical movement. Replace if required.
Remove the sponge, wash with water and car
shampoo, then soak it in a mixture of 50% petrol
and 50% specific oil. Press with your hand without
squeezing, allow it to drip dry and refit.
Time the system and check the timing system
components
Check that the following parts work properly:
valve; diaphragm; spring; and that the air calibration elements are clean; check if the sponge filter
is clean too
Adjust using the rpm indicator
Vespa GTS 125
Troubleshooting
Possible Cause
Pressure too low at the end of compression
Faulty spark plug or incorrect ignition advance
The starter remains on
Minimum nozzle dirty
Operation
Check the thermal group seals and replace worn
components
Replace the spark plug or check the ignition circuit
components
Check: electric wiring, circuit not interrupted, mechanical movement and power supply; replace if
necessary
Wash the nozzle with solvent and dry with compressed air
High fuel consumption
HIGH FUEL CONSUMPTION
Possible Cause
Loose nozzles
Fuel pump failure
Inefficient Starter
Air filter blocked or dirty
Incorrect float level
Operation
Check the maximum and minimum nozzles are
adequately fixed in their fittings
Check the low-pressure duct sealing
Check: electric wiring, circuit continuity, mechanical sliding and power supply
Remove the sponge, wash with water and car
shampoo, then soak it in a mixture of 50% petrol
and 50% specific oil. Press with your hand without
squeezing, allow it to drip dry and refit.
Restore the level in the tank by bending on the float
the thrusting reed of the petrol inlet rod so as to
have the float parallel to the tank level with the
carburettor inverted.
Transmission and brakes
Clutch grabbing or performing inadequately
IRREGULAR CLUTCH PERFORMANCE OR SLIPPAGE
Possible Cause
Faulty clutch
Operation
Check that there is no grease on the masses.
Check that the clutch mass contact surface with
the casing is mainly in the centre with equivalent
characteristics on the three masses. Check that
the clutch casing is not scored or worn in an anomalous way
Insufficient braking
INEFFICIENT BRAKING SYSTEM
Possible Cause
Inefficient braking system
Operation
Check the pad wear (1.5 min). Check that the
brake discs are not worn, scored or warped. Check
the correct level of fluid in the pumps and replace
brake fluid if necessary. Check there is no air in
TROUBL - 5
Vespa GTS 125
Troubleshooting
Possible Cause
Fluid leakage in hydraulic braking system
Brake disc slack or distorted
Operation
the circuits; if necessary, bleed the air. Check that
the front brake calliper moves in axis with the disc.
Failing elastic fittings, plunger or brake pump
seals, replace
Check the brake disc screws are locked; measure
the axial shift of the disc with a dial gauge and with
wheel mounted on the scooter.
Brakes overheating
BRAKES OVERHEATING
Possible Cause
Defective sliding of pistons
Brake disc slack or distorted
Clogged compensation holes on the pump
Swollen or glued rubber gaskets
Operation
Check calliper and replace any damaged part.
Check the brake disc screws are locked; use a dial
gauge and a wheel mounted on the vehicle to
measure the axial shift of the disc.
Clean carefully and blast with compressed air
Replace gaskets.
Electrical system
Battery
BATTERY
Possible Cause
Battery
Operation
This is the device in the system that requires the
most frequent attention and the most thorough
maintenance. If the vehicle is not used for some
time (1 month or more) the battery needs to be recharged periodically. The battery runs down completely in the course of 3 months. If the battery is
fitted on a motorcycle, be careful not to invert the
connections, keeping in mind that the black ground
wire is connected to the negative terminal while the
red wire is connected to the terminal marked+.
Turn signal lights malfunction
TURN INDICATOR NOT WORKING
Possible Cause
Electronic ignition device failure
Steering and suspensions
TROUBL - 6
Operation
With the key switch set to "ON" jump the contacts
1 (Blue - Black) and 5 (Red/Blue) on the control
unit connector. If by operating the turn indicator
control the lights are not steadily on, replace the
control unit; otherwise, check the cable harness
and the switch.
Vespa GTS 125
Troubleshooting
Heavy steering
STEERING HARDENING
Possible Cause
Steering hardening
Operation
Check the tightening of the top and bottom ring
nuts. If irregularities continue in turning the steering even after making the above adjustments,
check the seats in which the ball bearings rotate:
if they are recessed or if the balls are squashed,
replace them.
Excessive steering play
EXCESSIVE STEERING CLEARANCE
Possible Cause
Torque not conforming
Operation
Check the tightening of the top and bottom ring
nuts. If irregularities continue in turning the steering even after making the above adjustments,
check the seats in which the ball bearings rotate:
if they are recessed or if the balls are squashed,
replace them.
Noisy suspension
NOISY SUSPENSION
Possible Cause
Malfunctions in the suspension system
Operation
If the front suspension is noisy, check: the efficiency of the front shock absorbers; the condition of
the ball bearings and relevant lock-nuts, the limit
switch rubber buffers and the movement bushings.
In conclusion, check the tightening torque of the
wheel hub, the brake calliper, the shock absorber
disk in the attachment to the hub and the steering
tube.
Suspension oil leakage
OIL LEAKAGE FROM SUSPENSION
Possible Cause
Seal fault or breakage
Operation
Replace the shock absorber Check the condition
of wear of the steering covers and the adjustments.
TROUBL - 7
Troubleshooting
TROUBL - 8
Vespa GTS 125
INDEX OF TOPICS
ELECTRICAL SYSTEM
ELE SYS
Electrical system
KEY
1. Electronic ignition device
2. Immobilizer aerial
3. Magneto flywheel - Pick-up
4. Engine stop switch
5. Voltage regulator
6. Main fuse
7. Battery
8. Starter motor
9. Start-up remote control switch
10. Starter button
11. Fuses
12. Stop button on rear brake
13. Stop button on front brake
14. Wiring for antitheft device
15. Light switch
16. Light remote control
17. Rear left turn indicator
18. Rear light
A. Tail light bulb
ELE SYS - 2
Vespa GTS 125
Vespa GTS 125
Electrical system
B. Stop light bulb
C. License plate bulb
19. Rear right turn indicator
20. Front left turn indicator
21. Front position light
22. Front light
A. Tail light bulb
B. Headlight bulb
23. Front right turn indicator
24. Instrument panel
25. Fuel level transmitter
26. Engine oil pressure sensor
27. Thermistor
28. Turn indicator switch
29. Horn
30. Horn button
31. Thermoswitch
32. Electric fan
33. Key switch
34. Saddle opening actuator
35. Saddle opening button
36. Fuel pump
37. Fuel electric pump control device
38. Spark plug
39. HV coil
40. Automatic starter
Key
Ar: Orange Az: Sky blue Bi: White Bl: Blue Gi: Yellow Gr:Grey
Ma:Brown Ne: Black Ro: Pink Rs: Red Ve: Green Vi: Purple
Conceptual diagrams
ELE SYS - 3
Electrical system
Ignition
KEY
1. Electronic ignition device
2. Immobilizer aerial
4. Engine stop switch
6. Main fuse
7. Battery
33. Key switch
38. Spark plug
39. HV coil
ELE SYS - 4
Vespa GTS 125
Vespa GTS 125
Electrical system
Headlights and automatic starter section
KEY
1. Electronic ignition device
4. Engine stop switch
6. Main fuse
7. Battery
11. Fuses
15. Light switch
16. Light remote control
18. Rear light
A. Tail light bulb
C. License plate bulb
21. Front position light
22. Front light
A. Tail light bulb
B. Headlight bulb
24. Instrument panel
33. Key switch
40. Automatic starter
ELE SYS - 5
Electrical system
Battery recharge and starting
KEY
1. Electronic ignition device
3. Magneto flywheel - Pick-up
4. Engine stop switch
5. Voltage regulator
6. Main fuse
7. Battery
8. Starter motor
9. Start-up remote control switch
10. Starter button
11. Fuses
12. Stop button on rear brake
13. Stop button on front brake
18. Rear light
B. Stop light bulb
33. Key switch
ELE SYS - 6
Vespa GTS 125
Vespa GTS 125
Electrical system
Level indicators and enable signals section
KEY
1. Electronic ignition device
2. Immobilizer aerial
4. Engine stop switch
6. Main fuse
7. Battery
11. Fuses
24. Instrument panel
25. Fuel level transmitter
26. Engine oil pressure sensor
27. Thermistor
33. Key switch
ELE SYS - 7
Electrical system
Devices and accessories
KEY
1. Electronic ignition device
4. Engine stop switch
6. Main fuse
7. Battery
11. Fuses
14. Wiring for antitheft device
17. Rear left turn indicator
19. Rear right turn indicator
20. Front left turn indicator
23. Front right turn indicator
24. Instrument panel
28. Turn indicator switch
29. Horn
30. Horn button
31. Thermoswitch
32. Electric fan
33. Key switch
ELE SYS - 8
Vespa GTS 125
Vespa GTS 125
Electrical system
34. Saddle opening actuator
35. Saddle opening button
36. Fuel pump
37. Fuel electric pump control device
Checks and inspections
This section is devoted to the checks on the electrical system components.
Immobiliser
The electric ignition system is fed with direct current and is protected by an antitheft immobilizer
integrated to the control unit.
The ignition system consists of:
-Control unit
-Immobilizer aerial
-Master and service keys with built-in transponder
- HV coil
-Diagnosis LED
The diagnosis LED also works as a blinking light
to deter theft. This function is activated every time
the ignition switch is turned to the "OFF" position,
or the emergency stop switch is turned to the
"OFF" position. It remains activated for 48 hours in
order not to affect the battery charge.
When the key switch is turned to "ON", it interrupts
the function of the immobiliser lamp and a start
enable lamp comes "ON".
The duration of the flash depends on the electronic
control unit program (see figure).
In case the LED turns off and remains so even
when switching over to "ON", check if:
-The battery is charged
-The 15A main fuse (No. 7) is in working order
If the deterring LED remains off, check the control
unit power supply as follows:
- Disconnect the control unit connector and check
if:
ELE SYS - 9
Electrical system
- There is battery voltage between terminal No. 4
(Red/Black) and the ground lead.
- There is battery voltage between the terminal No.
4 (Red/Black) and the terminal No. 8 (Negative) as
shown in the figure.
- There is battery voltage between terminals No. 5
and No. 8 with the key switch set to "ON", and the
emergency cut-off switch set to "RUN".
If no faults are found, replace the control unit; otherwise check the wiring and the following components:
-Emergency cut-off switch
-Key switch contacts
Virgin circuit
If the ignition system has not been programmed,
the engine can be started but it will run limited to
2000 rpm. When trying to accelerate, some evident loss of power may be felt.
To program the system, besides setting the emergency cut-off switch to "RUN", use the (Red) MASTER and (Black) SERVICE keys as follows:
- Insert the MASTER key, turn it to "ON" and keep
it in that position for 2 seconds (limit values: 1 ÷ 3
seconds).
- Alternately insert all the available Black keys setting each of them to "ON" for 2 seconds.
- Insert the MASTER key again and turn it to "ON"
for 2 seconds. The maximum time to change keys
is 10 seconds.
A maximum of 3 (Black) service keys can be programmed at one time.
Sequence and times must be strictly observed or
it will be necessary to repeat the procedure from
the start. Once the control unit has been programmed, the control unit is inseparably matched with
the MASTER key transponder.
ELE SYS - 10
Vespa GTS 125
Vespa GTS 125
Electrical system
This matching allows programming further service
keys in case of loss, replacement, etc. Each new
time new data is programmed the previously stored one is deleted. If a service key should become
un-coded, the efficiency of the high voltage circuit
shielding must be thoroughly inspected: In any
case it is advisable to use resistive spark plugs.
Characteristic
Shielded cap resistance
~ 5000 Ω.
Diagnostic codes
The flash indicating the switching to "ON" can be followed by a phase of programmed failure warnings.
That is, the led is off for 2 seconds, and then diagnosis codes are transmitted with 0.5-second flashes.
After the failure code indication, a steadily on LED signals that ignition is disabled; see the table:
2-FLASH CODE - Example with programmed control unit, no transponder and/or malfunctioning aerial.
Ignition disabled-Vehicle immobilised
3-FLASH CODE - Example with programmed control unit, aerial working properly and unknown transponder code. Ignition disabled-Vehicle immobilised
Diagnostic code - 2 flashes
Diagnosis code: 2-flashes
When the 2-flash code is detected, carry out the following checks:
- Check if the failure continues after changing key (MASTER key included). If the failure persists with
any key, disconnect the aerial connector from the control unit and check the aerial continuity with the
020331Y multimeter.
If non-conforming values are measured, replace the aerial.
If no failures are found in the aerial, replace the control unit.
ELE SYS - 11
Electrical system
Vespa GTS 125
CAUTION
BEFORE PROGRAMMING THE NEW ELECTRONIC CONTROL UNIT CHECK THAT NO FAILURE
CODE IS INDICATED. THIS IS TO AVOID SPOILING A NEW CONTROL UNIT UNNECESSARILY.
Electric characteristic
immobilizer aerial
~ 7 ÷ 9 Ohm
Diagnostic code - 3 flashes
If the 3-flash code is detected, check if the failure
occurs when the MASTER key in inserted into the
key switch.
- If the failure disappears when the MASTER key
is used, proceed to encode the service keys
(Black).
- If the failure persists, it means that the MASTER
key and the control unit are not linked; in this case,
replace the control unit and then encode the keys.
The immobilizer system is efficient when, after
switching over to "ON", only a 0.7-second flash is
detected (see diagram).
In this case, the engine can be started.
Example with programmed control unit, transponder, programmed key and aerial working properly.
The ignition is enabled (regular use conditions)
Ignition circuit
Once the immobilizer system is enabled, the HV coil and the signals from the Pick-Up will produce a
spark in the spark plug.
The battery provides the basic power supply. The system is adjusted so that the start-up system immediately detects an eventual battery voltage drop, but this is practically irrelevant for the ignition
system.
The Pick-Up is connected to the control unit by a single cable; then, for the ground circuit, the control
unit is connected to the Pick-Up by the chassis and the engine ground lead.
To avoid disturbances in the ignition system during start-up, it is very important that the engine-chassis
ground connection bonding is efficient.
ELE SYS - 12
Vespa GTS 125
Electrical system
No spark plug
Once the lack of power to the spark plug has been
detected and the LED indicates it can be ignited,
follow this procedure:
- Pick-Up check.
Disconnect the control unit connector and check
that the cable between terminal No. 2 (Green) and
terminal No. 8 (Black) is not interrupted. Check the
Pick-Up and its power line:
Electric characteristic
Pick-up resistance value
Pick-up resistance value: 105 ÷ 124 Ohm
If a break in the circuit is found, check again the flywheel and the engine ground connectors (see engine
manual). If non-conforming values are measured, replace the Pick-Up; otherwise, repair the cable harness.
In case conforming values are measured, try replacing the control unit (without programming) and make
sure the failure has been solved by checking sparks are produced in the spark plug; only then program
the control unit.
- HV coil primary check
Disconnect the control unit connector and check
that the cable between terminal No. 3 and terminal
No. 8 is not interrupted (see figure).
If non-conforming values are measured, check
again the HV coil primary directly on the positive
and negative terminals.
If non-conforming values are measured, repair the
cables or replace the HV coil.
N.B.
THE MULTIMETER MUST BE SELECTED TO
DETECT CONTINUOUS VOLTAGE.
Electric characteristic
Resistance value:
0.4 ÷ 0.5 Ohm
ELE SYS - 13
Electrical system
- HV coil secondary check
Disconnect the spark plug cap from the HV cable
and measure the resistance between the HV cable
terminal and the HV coil negative terminal (see
figure).
If non-conforming values are measured, replace
the HV coil. To carry out a more complete diagnosis, check the peak voltage with the multimeter
adaptor.
Specific tooling
020409Y Multimeter adaptor - Peak voltage detection
Electric characteristic
Resistance value:
~ 3000 ± 300 Ohm
- Pick-Up
Disconnect the control unit connector and connect
the positive wire to connector No. 2 and the negative wire to connector No. 8 (see figure).
Use the start-up system to run the engine and
measure the voltage produced by the Pick-Up.
Replace Pick-Up if non-conforming values are
measured.
N.B.
THE MULTIMETER MUST BE SELECTED TO
DETECT CONTINUOUS VOLTAGE.
Electric characteristic
Resistance value:
> 2 Volt
- HV coil
With the control unit and HV coil connected, measure the voltage of the coil primary during the startup test with the voltage peak adaptor and connecting the positive terminal to the ground one and
the negative to the coil positive connector.
If non-conforming values are measured, replace
the control unit.
N.B.
ELE SYS - 14
Vespa GTS 125
Vespa GTS 125
Electrical system
THE PLASTIC CAP OF THE POSITIVE TERMINAL ON THE HV COIL PRIMARY IS BLACK
AND THE NEGATIVE TERMINAL ONE IS
GREEN.
Electric characteristic
Resistance value:
> 100 Volt
Battery recharge circuit
The recharge system is provided with a three phase alternator with permanent flywheel.
The alternator is directly connected to the voltage regulator.
In turn, the latter is directly connected to earth and to the battery positive passing through the 15A safety
fuse.
This system therefore requires no connection to the key switch.
The three- phase generator provides good recharge power and at low revs a good compromise is
achieved between generated power and idle stability.
For this reason, it is very important that the idle speed is adjusted as prescribed.
Specific tooling
020333Y Single battery charger
020334Y Multiple battery charger
Stator check
- With a tester, check the circuit between connections 5-3 and 5-1 is not interrupted.
- Check the earth isolation on the three phases of
stators 5-earth, 3-earth, 1-earth.
Stage indicative resistance: 0.7 - 0.9 Ω
Minimum oil pressure switch check
- With a tester, check the circuit between connections 4 and ground (with engine off) is not interrupted.
Pick-Up check
- Check that there is a resistance of about 105 ÷
124 Ω at 20° C between connection 2 and ground.
- In case of values different from the ones stated,
replace the defective parts.
N.B.
VALUES ARE STATED AT AMBIENT TEMPERATURE. A CHECK WITH THE STATOR AT OPELE SYS - 15
Electrical system
ERATING TEMPERATURE MAY RESULT IN
VALUES HIGHER THAN THOSE STATED.
Voltage regulator check
With a perfectly charged battery and lights off,
measure voltage at the battery poles with a high
running engine.
The voltage should not exceed 15.2 Volt.
In case higher voltages are detected, replace the
regulator.
In case of voltage values lower than 14 Volt, check
the stator and the corresponding cable harness.
Recharge system voltage check
Connect an ammeter induction clamp to the voltage regulator positive terminal, measure the battery voltage and turning on the vehicles lights with
engine off, wait for the voltage to set at about 12
V. Start the engine and measure the current generated by the system with lights on and a high
running engine.
In case the generated current value is lower than
10A, repeat the test using a new regulator and/
stator alternatively.
Choke Inspection
Refer to the engine section to check the resistance
and operating conditions of the component. As regards voltage supply, keep the connector connected to the system and check that the two terminals
receive battery voltage when the engine is on (see
figure).
If no voltage is detected, connect the multimeter
negative probe to the ground lead and the positive
ELE SYS - 16
Vespa GTS 125
Vespa GTS 125
Electrical system
probe to the automatic starter Orange cable; with
the key switch set to "ON" check whether there is
battery voltage; if there is no voltage, check the
wiring connections to the key switch and that the
15A fuse (No. 7) works properly.
If there is voltage, check again the ignition control
unit connector.
After disconnecting the starter, start up the engine
and keep it at idle speed; then check whether there
is voltage connecting the multimeter with the positive probe to terminal No. 5 (Blue), and the negative one to terminal No. 7 (White/Black) (see
figure).
If there is no voltage, replace the control unit after
making sure that the fuses are not blown; otherwise, check the cable harness between the starter
and the control unit and, as a last resource, replace the starter.
Turn signals system check
- If the turn indicators do not work, proceed as follows:
-Disconnect the control unit connector and check that there is battery voltage between terminal No.4
(Red/Black) and the ground lead.
-Check that the same happens between terminal No. 4 and terminal No. 8 (Black).
-Repeat the check between terminal No. 5 (Sky blue) and terminal No. 8 (Black) with the key switch set
to "ON" and the emergency switch set to "RUN".
ELE SYS - 17
Electrical system
Vespa GTS 125
If no voltage is detected, check the cable harness, the connections and make sure the 15A main fuse
is in good conditions; otherwise, proceed as follows:
- Jump terminals No.1 (Black/Blue) and No. 4 (Red/Black) (see figure), and set the turn indicator switch
alternately to the left and to the right and check that the lights turn on.
If they do, replace the control unit because it is faulty.
If they do not turn on, check the control unit-turn indicator switch connection cable harness; then, repeat
the test.
If the cable harness is in good conditions and the turn indicators still do not turn on, replace the turn
indicator switch because it is faulty.
ELE SYS - 18
Vespa GTS 125
Electrical system
Fuses
The electrical system is equipped with:
1. six protection fuses «A» located in the glove
compartment to the left
2. one 15A fuse «B» located under the helmet
compartment under the saddle hinge latch.
The chart shows the position and characteristics
of the fuses in the vehicle.
CAUTION
BEFORE REPLACING THE BLOWN FUSE,
FIND AND SOLVE THE FAILURE THAT
CAUSED IT TO BLOW. NEVER TRY TO REPLACE THE FUSE WITH ANY OTHER MATERIAL (E.G., A PIECE OF ELECTRIC WIRE).
CAUTION
MODIFICATIONS OR REPAIRS TO THE ELECTRICAL SYSTEM, PERFORMED INCORRECTLY OR WITHOUT STRICT ATTENTION TO THE
TECHNICAL SPECIFICATIONS OF THE SYSTEM, CAN CAUSE ERRORS IN FUNCTIONING
AND RISK OF FIRE.
FUSES
1
Specification
Fuse 1
2
Fuse 2
3
Fuse 3
Desc./Quantity
Current rating: 10 A
Protected circuits:
High-/low-beam
headlight bulb, highbeam warning light.
Current rating: 7.5
A
Protected circuits:
Saddle-opening actuator, immobilizer
LED, anti-theft device pre-installation,
key switch
Current rating: 7.5
A
Protected circuits:
Horn, antitheft device
pre-installation, oil
pressure sensor, oil
pressure warning
light, water temperature gauge, thermisELE SYS - 19
Vespa GTS 125
Electrical system
Specification
4
Fuse 4
5
Fuse 5
6
Fuse 6
7
Fuse 7
Desc./Quantity
tor, fuel gauge, low
fuel warning light,
fuel level transmitter.
Current rating: 5 A
Protected circuits:
Instrument panel
lighting bulbs and
warning lights, tail
lights, license plate
light.
Current rating: 5 A
Protected circuits:
Stop light, starter
motor.
Current rating: 3 A
Protected circuits:
Electric pump control
device, fuel electric
pump
Current rating: 15A
Protected circuits:
General
Dashboard
A = Digital clock with calendar
B = Cooling liquid temperature gauge
C = Right turn indicator warning light
D = Fuel gauge
E = Headlight warning light
F = High-beam warning light
G = Low oil pressure warning light
H = Low fuel warning light
I = Speedometer
L = Odometer
M = Left turn indicator warning light
N = Antitheft device LED (immobilizer)
A
1
2
3
4
5
6
ELE SYS - 20
Specification
Fuel gauge signal
High-beam warning light
Oil warning light
Fuel supply (+)
Low fuel warning light
Lighting
Desc./Quantity
Vespa GTS 125
Electrical system
B
1
2
3
4
Specification
Ground lead
Left turn indicator
Right turn indicator
Temperature signal
Desc./Quantity
Dry-charge battery
Battery cleaning
The battery should always be kept clean, especially on its top side, and the terminals should be coated
with Vaseline.
CAUTION
NEVER USE FUSES WITH A CAPACITY HIGHER THAN THAT RECOMMENDED.
USING A FUSE OF UNSUITABLE RATING MAY SERIOUSLY DAMAGE THE VEHICLE OR EVEN
CAUSE A FIRE.
CAUTION
DRINKING WATER CONTAINS MINERALS THAT CAN BE EXTREMELY HARMFUL TO THE BATTERY: USE DISTILLED WATER ONLY.
CAUTION
TO ENSURE MAXIMUM PERFORMANCE THE BATTERY MUST BE CHARGED BEFORE USE.
INADEQUATE CHARGING OF THE BATTERY WITH A LOW ELECTROLYTE LEVEL BEFORE IT
IS FIRST USED SHORTENS THE LIFE OF THE BATTERY.
Battery recharge
Normal bench charging must be carried out using the special (single or multiple) battery charger, setting
the battery charge selector to the type of battery that needs recharging (i.e., at a current equal to 1/10
of the battery rated capacity). Connections to the power supply source must be implemented by connecting corresponding poles (+ to + and - to - ).
WARNING
BEFORE RECHARGING THE BATTERY, REMOVE THE CAPS OF EACH CELL.
KEEP THE BATTERY AWAY FROM NAKED FLAMES OR SPARKS WHILE IT IS CHARGED.
FIRST DETACH THE NEGATIVE LEAD BEFORE REMOVING THE BATTERY FROM THE VEHICLE.
Specific tooling
020333Y Single battery charger
ELE SYS - 21
Electrical system
Vespa GTS 125
020334Y Multiple battery charger
Charging status check
After topping-up the electrolyte level, check the density using special densimeter
When the battery is charged, you should detect a density of 30 to 32 Bé corresponding to a specific
weight of 1.26 to 1.28 at a temperature of no lower than 15° C.
A density reading of less than 20° Bé indicates that the battery is completely flat and it must therefore
be recharged.
If the scooter is not used for a given time (1 month or more) it will be necessary to periodically recharge
the battery.
The battery runs down completely in the course of three months. If it is necessary to refit the battery in
the vehicle, be careful not to reverse the connections, remembering that the ground wire (black) marked
(-) must be connected to the -negative clamp while the other two red wires marked (+) must be connected to the clamp marked with the +positive sign.
Checking the electrolyte level
The electrolyte level must be checked frequently and must reach the upper level. Only use distilled
water, to restore this level. If it is necessary to add water too frequently, check the vehicle's electrical
system: the battery works overcharged and is subject to quick wear.
- Remove the short closed tube and the caps, then
pour sulphuric acid into the cells using the type
specified for batteries with a specific gravity of
1.26, corresponding to 30 Bé at a minimum temperature of 15°C until the upper level is reached.
- Allow to stand for at least 2 hours, then top up the
level with sulphuric acid.
- Within the following 24 hours, recharge with the
specific (single) or (multiple) battery charger at an
intensity approx. to 1/10 of the battery rated capacity and until the acid density is approximately
1.27, corresponding to 31º Bé, and these values
are stabilised.
- After charging, level the acid (adding distilled
water). Close and clean carefully.
- Once the above operations have been performed, install the battery in the vehicle ensuring
that it is wired up properly.
ELE SYS - 22
Vespa GTS 125
Electrical system
Specific tooling
020333Y Single battery charger
020334Y Multiple battery charger
1 Hold the vertical tube
2 Look at the level
3 The float must be freed
Battery installation
• Remove the battery cover after undoing the 4
screws shown in the photograph.
- Remove the strap fastening the battery
- Insert the battery breather pipe through the hole
shown in the photograph.
ELE SYS - 23
Electrical system
- Fit the battery as shown in the photograph.
N.B.
IN ORDER TO FIT THE CABLES ON THE BATTERY TERMINALS CORRECTLY, REST THE
LOWER END OF THE TERMINAL SIDE OF THE
BATTERY ON THE EDGE OF THE BATTERY
WELL.
- Using the screwdriver, tighten up the battery terminal cables as far as they will go, placing the
special Grover washer between the screw head
and the cable terminal.
N.B.
DO NOT USE WRENCHES TO TIGHTEN UP
THE SCREWS FOR FIXING THE TERMINALS
TO THE BATTERY TERMINALS
- Mount permanently the battery in the battery
chamber
- Refit the strap fastening the battery
ELE SYS - 24
Vespa GTS 125
Vespa GTS 125
Electrical system
- Refit the battery cover
ELE SYS - 25
Electrical system
ELE SYS - 26
Vespa GTS 125
INDEX OF TOPICS
ENGINE FROM VEHICLE
ENG VE
Engine from vehicle
Vespa GTS 125
This section describes the operations to carry out when removing the engine from the vehicle.
Exhaust assy. Removal
- Undo the two exhaust manifold fixings on the
head.
- Undo the three screws fixing the muffler to the
support arm.
Remove the full muffler unit.
Removal of the engine from the vehicle
-Carry out the removal operations but in reverse order and respect the locking torques indicated in the
Characteristics Chapter.
Check that there is a small clearance when the valve is in abutment against the set screw.
-Check the engine oil level and if necessary top it up with the recommended type.
- Top-up the cooling circuit.
- Check the functioning of the accelerator and the electrical devices.
CAUTION
PAY PARTICULAR ATTENTION TO POSITIONING THE THROTTLE COMMAND TRANSMISSION
PROPERLY.
ENG VE - 2
Vespa GTS 125
Engine from vehicle
- Disconnect the battery
- Remove the helmet compartment
- Remove the side fairings
Remove the full muffler assembly.
- Remove the air cleaner housing acting on the 3
screws indicated in the picture, by removing the
clamp from the blow-by pipe and disconnecting the
bellow connection to the carburettor acting on the
clamp as indicated in the photograph
CAUTION
THIS OPERATION MUST BE CARRIED OUT
WHEN THE ENGINE IS COLD.
- Remove the air intake manifold on the transmission housing acting on the two screws indicated in
the photograph and remove the plastic clip
ENG VE - 3
Engine from vehicle
- Remove the coolant inlet pipe to the pump as indicated in the photograph.
- Remove the fuel valve vacuum intake pipe from
"T" joint indicated in the photograph
- Remove the fuel supply pipe from the carburettor
- Remove the coolant outlet pipe from the engine
and the bleed pipe indicated in the photograph
ENG VE - 4
Vespa GTS 125
Vespa GTS 125
Engine from vehicle
- Remove the spark plug cap
- Remove the coolant temperature sensor connector indicated in the photo
- Remove the throttle control cable from the carburettor acting on the nut shown in the photo
- Remove the automatic starter connector from the
system located inside the protection sheath shown
in the photo
ENG VE - 5
Engine from vehicle
- Remove the positive and negative wires from the
starter motor as shown in the photograph
- Remove the connector from the flywheel wiring
shown in the photograph.
- Remove the cable from the retainer clamp on the
flywheel cover
- Remove the rear shock absorbers.
- Remove the hydraulic piping from the rear calliper by undoing the screw indicated in the photograph. Then remove the retainers fixing the piping
to the engine crankcase, indicated in the photograph.
ENG VE - 6
Vespa GTS 125
Vespa GTS 125
Engine from vehicle
- Use a jack to support the vehicle properly. Remove the engine-swinging arm fixing pin by acting
on the nut and the head of the pin indicated in the
photograph
- The engine is now free.
ENG VE - 7
Engine from vehicle
ENG VE - 8
Vespa GTS 125
INDEX OF TOPICS
ENGINE
ENG
Engine
Vespa GTS 125
This section describes the operations to be carried out on the engine and the tools to be used.
Automatic transmission
Transmission cover
- To remove the transmission cover it is necessary
to remove the plastic cover first, by inserting a
screwdriver in the slotted holes. Using the clutch
bell lock wrench shown in the figure, remove the
driven pulley shaft locking nut and washer.
Specific tooling
020423Y driven pulley lock wrench
- Remove the cap/dipstick from the engine oil filling
hole.
- Remove the ten screws.
- Remove the transmission cover.
If this operation is carried out directly on the vehicle, remove the cooling air supply coupling of the
transmission housing.
Air duct
- Remove the 4 screws and the housing.
ENG - 2
Vespa GTS 125
Engine
- To remove the intake throat on the transmission
cover, just remove the 2 fixing screws indicated in
the figure.
Removing the driven pulley shaft bearing
- Remove the clip from the inside of the cover.
- Remove the bearing from the crankcase by
means of:
Specific tooling
020376Y Adaptor handle
020375Y Adaptor 28 x 30 mm
020412Y 15 mm guide
Refitting the driven pulley shaft bearing
- Slightly heat the crankcase from the inside so as
not to damage the painted surface.
- Insert the bearing in its seat.
- Refit the seeger ring.
CAUTION
USE AN APPROPRIATE REST SURFACE TO
AVOID DAMAGING THE COVER PAINT.
N.B.
ALWAYS REPLACE THE BEARING WITH A
NEW ONE UPON REFITTING.
Specific tooling
020376Y Adaptor handle
020357Y 32 x 35 mm adaptor
020412Y 15 mm guide
ENG - 3
Engine
Removing the driven pulley
- Remove the spacer, the clutch bell and the whole
driven pulley unit.
N.B.
THE UNIT CAN ALSO BE REMOVED WITH THE
DRIVING PULLEY MOUNTED.
Inspecting the clutch drum
- Check that the clutch bell is not worn or damaged.
- Measure the clutch bell inside diameter.
Characteristic
Max. value clutch bell
Max. value: Ø 134.5 mm
Clutch bell standard value
Standard value: Ø 134 - 134.2 mm
Checking the bell working surface eccentricity
- Install the bell on a driven pulley shaft using 2
bearings (inner diameter 15 and 17 mm).
- Lock with the original spacer and nut.
- Place the bell/shaft assembly on the support to
check the crankshaft alignment.
- Using a feeler pin gauge and the magnetic base,
measure the bell eccentricity.
- Repeat the measurement in 3 positions (Central,
internal, external).
- If faults are found, replace the bell.
Specific tooling
020074Y Support base for checking crankshaft
alignment
020335Y Magnetic support for dial gauge
ENG - 4
Vespa GTS 125
Vespa GTS 125
Engine
Characteristic
clutch bell inspection: Limit eccentricity.
Admissible limit eccentricity: 0.15 mm
Removing the clutch
Removing the clutch
Fit the driven pulley spring compressor specific
tool with medium length pins screwed in position
F from the tool internal side.
- Insert the adapter ring 8 in the pins.
- Assemble the driven pulley assembly on the tool
introducing the rivets heads in the adapter ring.
- Make sure that the clutch is perfectly inserted into
the adapter ring before proceeding to loosen/tighten the clutch nut.
- Use the special 46x55 wrench component n°9 to
remove the nut fixing the clutch in place.
- Separate the driven pulley components (Clutch,
fan and spring with plastic fitting).
CAUTION
THE TOOL MUST BE FIRMLY FIXED IN THE
CLAMP AND THE CENTRAL SCREW MUST BE
BROUGHT INTO CONTACT WITH THE TOOL.
EXCESSIVE TORQUE CAN CAUSE THE SPECIFIC TOOL TO BUCKLE.
Specific tooling
020444Y009 46x55 Wrench
020444Y010 adapter ring
Inspecting the clutch
- Check the thickness of the clutch mass friction
material.
- The masses must not show traces of lubricants;
otherwise, check the driven pulley unit seals.
N.B.
UPON RUNNING-IN, THE MASSES MUST EXHIBIT A CENTRAL CONTACT SURFACE AND
MUST NOT BE DIFFERENT FROM ONE ANOTHER.
VARIOUS CONDITIONS CAN CAUSE THE
CLUTCH TO TEAR.
ENG - 5
Engine
CAUTION
DO NOT OPEN THE MASSES USING TOOLS
TO PREVENT A VARIATION IN THE RETURN
SPRING LOAD.
Characteristic
Check minimum thickness
1 mm
Pin retaining collar
- Simultaneously turn and pull the collar manually
to remove it.
N.B.
USE TWO SCREWDRIVERS IF YOU HAVE DIFFICULTY.
N.B.
BE CAREFUL NOT TO PUSH THE SCREW
DRIVERS IN TOO FAR TO AVOID DAMAGE
THAT COULD ENDANGER THE O-RING SEAL.
- Remove the four torque server pins and pull the
pulley halves apart.
Removing the driven half-pulley bearing
- Check there are no signs of wear and/or noisiness; - Replace with a new one if there are.
- Remove the retaining ring using two flat blade
screwdrivers.
- Support the pulley bushing adequately from the
threaded side using a wooden surface.
- Using a hammer and pin, knock the ball bearing
out as shown in the figure.
- Support the pulley properly using the bell as shown in the figure.
ENG - 6
Vespa GTS 125
Vespa GTS 125
Engine
Specific tooling
001467Y035 Belle for OD 47-mm bearings
- Remove the roller bearing using the modular
punch.
Specific tooling
020376Y Adaptor handle
020456Y Ø 24 mm adaptor
020363Y 20 mm guide
Inspecting the driven fixed half-pulley
- Measure the outer diameter of the pulley bushing.
- Check the contact surface with the belt to make
sure there are no flaws.
Characteristic
Half-pulley standard diameter
Standard diameter: Ø 40.985 mm
Half-pulley minimum diameter
Minimum admissible diameter Ø 40.96 mm
Inspecting the driven sliding half-pulley
- Remove the two internal grommets and the two
O-rings.
- Measure the movable half-pulley bushing inside
diameter.
Characteristic
Movable driven half-pulley max. diameter
Max. diameter admitted: Ø 41.08 mm
Movable driven half-pulley standard diameter
Standard diameter: Ø 41.000 ÷ 41.035 mm
ENG - 7
Engine
Refitting the driven half-pulley bearing
- Support the pulley bushing adequately from the
threaded side using a wooden surface.
- Fit a new roller sleeve as in the figure.
- For the fitting of the new ball bearing, follow the
example in the figure using a modular punch.
Fit the retention ring
WARNING
N.B.
FIT THE BALL BEARING WITH THE VISIBLE
SHIELD
Specific tooling
020376Y Adaptor handle
020375Y Adaptor 28 x 30 mm
020424Y Driven pulley roller casing fitting
punch
Refitting the driven pulley
- Insert the new oil guards and O-rings on the movable half-pulley.
- Lightly grease the O-rings (A) shown in the figure.
ENG - 8
Vespa GTS 125
Vespa GTS 125
Engine
- Fit the half-pulley over the bushing using the appropriate tool
- Check that the pins are not worn and proceed to
refitting them in their slots.
- Refit the torque server closure collar.
Using a curved-spout grease gun, lubricate the
driven pulley assembly with approximately 6 g of
grease. Apply the grease through one of the holes
in the bushing until it comes out through the hole
on the opposite side. This operation is necessary
to avoid the presence of grease beyond the Orings.
N.B.
THE TORQUE SERVER CAN BE GREASED
WHETHER WITH BEARINGS FITTED OR
WHEN THEY ARE BEING REPLACED; UNDERTAKING THE OPERATION WHEN THE BEARINGS ARE BEING SERVICED MIGHT BE EASIER.
Specific tooling
020263Y Sheath for driven pulley fitting
Recommended products
AGIP GREASE SM 2 Grease for the tone wheel
revolving ring
Soap-based lithium grease containing NLGI 2 Molybdenum disulphide; ISO-L-XBCHB2, DIN
KF2K-20
ENG - 9
Engine
Inspecting the clutch spring
- Measure the length of the movable driven halfpulley spring while it is unloaded.
Characteristic
Standard length
106 mm
acceptable limit after use:
101 mm
Refitting the clutch
- Support the driven pulley spring compressor appropriate tool with the control screw in vertical axis.
- Arrange the tool with the medium length pins
screwed in position «F» on the inside.
- Insert the adapter ring 8 in the pins.
- Preassemble the cooling fan to the clutch in such
a way that the keying facets are aligned and the 3
pin heads (A) of the mass axis can be seen in full.
- Insert the clutch on the adapter ring.
- Lubricate the end of the spring that abuts against
the servo-system closing collar.
- Insert the spring with its plastic holder in contact
with the clutch.
- Insert the driving belt into the pulley unit according to their direction of rotation.
- Insert the pulley unit with the belt into the tool.
- Slightly preload the spring.
- Make sure that the clutch is perfectly inserted into
the adapter ring before proceeding to tighten the
clutch nut.
- Place the tool in the clamp with the control screw
on the horizontal axis.
- Fully preload the spring.
- Apply the clutch lock nut and tighten it to the
specified torque using the specific 46x55 spanner.
ENG - 10
Vespa GTS 125
Vespa GTS 125
Engine
- Loosen the tool clamp and insert the belt according to its direction of rotation.
- Lock the driven pulley again using the specific
tool.
- Preload the clutch return spring with a traction/
rotation combined action until it reaches the pulleys maximum opening and place the belt on the
minimum rolling diameter.
- Remove the driven pulley /belt assembly from the
tool.
N.B.
FOR DESIGN REASONS, THE NUT IS SLIGHTLY ASYMMETRIC; THE FLATTEST SURFACE
SHOULD BE MOUNTED IN CONTACT WITH
THE CLUTCH.
N.B.
DURING THE SPRING PRELOADING PHASE,
BE CAREFUL NOT TO DAMAGE THE PLASTIC
SPRING STOP AND THE BUSHING THREADING.
N.B.
AN EXCESSIVE QUANTITY CAN DAMAGE THE
CLUTCH OPERATION.
Specific tooling
020444Y011 adapter ring
020444Y009 46x55 Wrench
Locking torques (N*m)
Clutch unit nut on driven pulley 55 ÷ 60
Refitting the driven pulley
- Reassemble the clutch bell and spacer.
ENG - 11
Engine
Drive-belt
- Check that the driving belt is not damaged.
- Check the width of the belt.
Characteristic
125 4T driving belt - minimum width:
21.5 mm
125 4T driving belt - standard width:
22.5 ± 0.2 mm
250 4T Transmission belt/minimum width
19.5 mm
250 4T Transmission belt/standard width
21.3 ± 0.2 mm
During the wear checks foreseen in the scheduled
maintenance services at 6,000 km, 18,000 km,
etc., check that the rim bottom of the toothing does
not show signs of incisions or cracking (see figure):
The rim bottom of the tooth must not have incisions
or cracking; if it does, change the belt.
Removing the driving pulley
- With the appropriate tool, remove the nut with the
built-in Belleville washer, the drive common to the
kick-starter version, and the steel washer.
- Remove the fixed driving half-pulley.
- Remove the steel washer separating from the
bushing.
Appropriate tools:
Specific tooling
020368Y driving pulley lock wrench
ENG - 12
Vespa GTS 125
Vespa GTS 125
Engine
Inspecting the rollers case
- Check that the internal bushing shown in the figure is not abnormally worn and measure inner
diameter A.
- Measure outer diameter B of the pulley sliding
bushing shown in the figure.
- Check that the rollers are not damaged or worn.
- Check the guide shoes for the variator back-plate
are not worn.
- Check the wear of the roller housings and of the
belt contact surfaces on both pulley halves.
- Check that stationary driving pulley does not
show signs of abnormal wear on the grooved edge
and on the surface in contact with the belt.
- Check that the O-ring is not pushed out of shape.
CAUTION
DO NOT LUBRICATE OR CLEAN SINTERED
BUSHINGS
Characteristic
Movable driving half-pulley bushing: Standard
Diameter
26.000 - 26.021 mm
Movable driving half-pulley bushing: Maximum allowable diameter
Ø 26.12 mm
Sliding bushing: Standard Diameter
Ø 25.959 ÷ 25.98 mm
Sliding bushing: Minimum admissible diameter
Ø 25.95 mm
Roller: Standard Diameter
Ø 18.9 ÷ 19.1 mm
Roller: Minimum diameter permitted
Ø 18.5 mm
ENG - 13
Engine
Refitting the driving pulley
- Preassemble the movable half-pulley with the
roller contrast plate by putting the rollers in their
housings with the larger support surface touching
the pulley according to the direction of rotation.
- Check that the roller contact plate does not have
flaws and is not damaged on the grooved edge.
- Mount the complete bushing unit on the driving
shaft.
- Fit the driven pulley/Clutch/belt unit on the engine.
ENG - 14
Vespa GTS 125
Vespa GTS 125
Engine
- Correctly refit the previously removed Bendix
back to its position.
- Reassemble the parts of the unit (internal lining,
fixed half-pulley, external lining, drive and nut),
spread Loctite 243 Quick Set threadlock on the
thread and tighten the nut to the prescribed torque.
- Avoid the half-pulley rotation with the appropriate
stop key tool..
- Rotate the engine manually until the belt is slightly taut.
CAUTION
IT IS EXTREMELY IMPORTANT THAT THE
BELT IS PERFECTLY FREE WHEN THE FIXED
DRIVING HALF-PULLEY IS ASSEMBLED. THIS
IS TO AVOID CARRYING OUT A WRONG
TIGHTENING OF THE DRIVING HALF-PULLEY.
Specific tooling
020368Y driving pulley lock wrench
Locking torques (N*m)
Drive pulley nut 75 ÷ 83
Refitting the transmission cover
- Check the presence of the 2 centring dowels and
the correct installation of the sealing gasket for the
oil sump on the transmission cover.
- Replace the cover tightening the 10 screws at the
specified torque.
- Refit the oil loading cap/bar.
- refit the steel washer and the driven pulley nut.
- Tighten the nut to the prescribed torque using the
lock wrench and the torque wrench tools.
- Replace the plastic cover.
Specific tooling
020423Y driven pulley lock wrench
Locking torques (N*m)
Transmission cover screws 11 ÷ 13 Driven pulley shaft nut 54 ÷ 60
End gear
ENG - 15
Engine
Removing the hub cover
- Empty the rear hub through the oil drainage plug.
- Remove the 7 flanged screws indicated in the
figure.
- Remove the hub cover and its gasket.
Removing the wheel axle
- Remove the wheel axis complete with gear.
- Remove the intermediate gear.
Removing the hub bearings
- Check the state of the bearings being examined
(wear, clearance and noisiness). If faults are detected, do the following.
- Use the specific bearing extractor to remove the
three 15 mm bearings (2 in the crankcase and 1 in
the hub cover).
Specific tooling
001467Y013 Pliers to extract ø 15-mm bearings
ENG - 16
Vespa GTS 125
Vespa GTS 125
Engine
Removing the wheel axle bearings
Hold up the hub cover and take out the bearing.
Specific tooling
020376Y Adaptor handle
020477Y Adaptor 37 mm
020483Y 30 mm guide
With the appropriate tools, remove the oil seal as
shown in the figure.
Specific tooling
020359Y 42x47-mm adaptor
ENG - 17
Engine
Removing the driven pulley shaft bearing
When removing the driven pulley shaft, the corresponding bearing and oil seal, remove the transmission cover and the clutch group as explained
above.
- Extract the driven pulley shaft from its bearing.
- Remove the oil guard using a screwdriver, working from inside the bearing and being careful not
to damage the housing, make it come out of the
belt transmission side.
- Remove the seeger ring shown in the figure
With the sectional punch, remove the driven pulley
shaft bearing.
Specific tooling
020376Y Adaptor handle
020375Y Adaptor 28 x 30 mm
020363Y 20 mm guide
Inspecting the hub shaft
- Check the three shafts for wear or distortion of
the toothed surfaces, the bearing housings, and
the oil seal housings.
- In case of anomalies, replace the damaged components.
Inspecting the hub cover
- Check that the fitting surface is not dented or distorted.
- Check the bearing bearings.
- In case of anomalies, replace the damaged components.
ENG - 18
Vespa GTS 125
Vespa GTS 125
Engine
Refitting the wheel axle bearing
Support the hub cover on a wooden surface.
- Heat the cover crankcase with special heat gun.
- Fit the wheel shaft bearing with a modular punch
as shown in the figure.
Specific tooling
020150Y Air heater support
020151Y Air heater
020376Y Adaptor handle
020360Y Adaptor 52 x 55 mm
020483Y 30 mm guide
Assemble the seeger ring.
- Fit the oil guard with seal lip towards the inside
of the hub and place it flush with the internal surface by means of the appropriate tool used from
the 52 mm side.
The 52 mm side of the adapter must be turned towards the bearing.
ENG - 19
Engine
Vespa GTS 125
Refitting the hub cover bearings
For the fitting of the hub box bearings the engine
crankcase and the cover must be heated with the
special heat gun.
- The three 15 mm bearings must be fitted using
the appropriate tools.
- The 42-mm side of the adapter must be turned
towards the bearing.
Specific tooling
020150Y Air heater support
020151Y Air heater
020376Y Adaptor handle
020359Y 42x47-mm adaptor
020412Y 15 mm guide
N.B.
TO FIT THE BEARING ON THE COVER, SUPPORT THE COVER WITH THE STUD BOLT SET.
- Refit the driven pulley shaft bearing with a modular punch as shown in the figure.
N.B.
IF THE BEARING HAS AN ASYMMETRICAL
BALL RETAINER, PLACE IT SO THAT THE
BALLS ARE VISIBLE FROM THE HUB INNER
SIDE.
Specific tooling
020376Y Adaptor handle
020359Y 42x47-mm adaptor
020363Y 20 mm guide
N.B.
WHEN FITTING THE BEARINGS ON THE ENGINE CRANKCASE, SUPPORT THE CRANKCASE
PREFERABLY ON A SURFACE TO ALLOW THE BEARINGS TO BE DRIVEN VERTICALLY.
- Refit the seeger ring with the opening facing the bearing and fit a new oil guard flush with the crankcase
from the pulley side.
Refitting the hub bearings
- Install the three shafts in the engine crankcase as shown in the figure.
ENG - 20
Vespa GTS 125
Engine
Refitting the ub cover
- Fit a new gasket together with the centring dowels.
- Seal the gasket of the breather pipe using black silicone sealant.
- Fit the gearbox cover, making sure the breather pipe is in the correct position.
- Place the 3 shortest screws, identifiable by their different colour, as shown in the figure.
- Fasten the breather pipe support bracket with the lower short screw.
- Assemble the remaining 4 screws and tighten the 7 screws to the prescribed torque.
Locking torques (N*m)
Rear hub cover screws 24 ÷ 27
ENG - 21
Engine
Flywheel cover
Removing the hub cover
- Remove the two clamps, the two couplings and
empty the cooling system.
- Remove the 4 retainers and the flywheel cover
Removing the stator
- Remove the electric terminal of the minimum oil
pressure switch.
- Remove the two Pick-Up screws and the one for
the wiring harness bracket as well as the two stator
fixing screws shown in the figure.
- Remove the stator and its wiring.
ENG - 22
Vespa GTS 125
Vespa GTS 125
Engine
Refitting the stator
- Refit the stator and flywheel carrying out the removal procedure in reverse, tightening the retainers to the prescribed torque.
- Place the cable harness as shown in the figure.
- Stator screws and Pick-Up
N.B.
THE PICK-UP WIRE SHOULD BE POSITIONED
BETWEEN THE UPPER SCREW AND THE REFERENCE PIN AS SHOWN IN THE DETAIL
DRAWING.
Locking torques (N*m)
Stator assembly screws (°) 3 ÷ 4
Refitting the flywheel cover
- Place the flywheel with the top dead centre mark
aligned with the crankcase.
- Place the flywheel cover by aligning the reference
marks of the drive and the crankcase cover.
- Reassemble the cover on the engine, placing the
three connectors in the drive for the water pump.
- Carry out the steps in the reverse order from the
dismantling procedure.
CAUTION
TAKE CARE TO CORRECTLY POSITION THE
FLYWHEEL CONNECTOR. MAKE SURE THE
CENTRING DOWELS ARE PRESENT.
Flywheel and starting
- Check the integrity of the internal plastic parts of the flywheel and the Pick-Up control plate.
ENG - 23
Engine
Vespa GTS 125
Removing the flywheel magneto
- Lock the rotation of the Flywheel with the calliper
spanner tool.
- Remove the nut.
- Take out the flywheel.
CAUTION
THE USE OF A CALLIPER SPANNER OTHER
THAN THE ONE SUPPLIED COULD DAMAGE
THE STATOR COILS
N.B.
THE FLYWHEEL OF THE 200 CM³ MODELS
FEATURES ENHANCED INERTIAL MASS.
Inspecting the flywheel components
- Check the integrity of the internal plastic parts of the flywheel and the Pick-Up control plate.
Refitting the flywheel magneto
- Fit the flywheel being careful to insert the key
properly.
- Lock the flywheel nut to the prescribed torque
- Check that the Pick-Up air gap is between 0.34
÷ 0.76 mm.
The air gap cannot be modified when assembling
the Pick-Up.
Different values result from deformations visible
on the Pick-Up support.
N.B.
A VARIATION IN THE AIR GAP DISTANCE
MODIFIES THE IGNITION SYSTEM IDLE
SPEED
Specific tooling
020565Y Flywheel lock calliper spanner
Locking torques (N*m)
ENG - 24
Vespa GTS 125
Engine
Flywheel nut 54 ÷ 60
Refitting the starter motor
- Fit a new O-ring on the starter motor and lubricate
it.
- Fit the starter on the crankcase, locking the two
screws to the prescribed torque.
Locking torques (N*m)
Starter motor screws 11 ÷ 13
Cylinder assy. and timing system
Removing the intake manifold
- Remove the flywheel cover completely as described in the flywheel cover section.
- Loosen the 3 crews and remove the intake manifold.
N.B.
SCREWS AGAINST ACCIDENTAL OPERATION ARE PROVIDED.
ENG - 25
Engine
Removing the rocker-arms cover
- Remove the 5 screws indicated in the figure
Removing the timing system drive
- Remove the parts listed below first: transmission
cover, drive pulley with belt, oil sump with spring
and by-pass piston, oil pump pulley cover, O-ring
on the crankshaft and the sprocket wheel separation washer.
- Remove the tappet cover.
- Remove the central screw fastener and the automatic valve-lifter retaining cover, as shown in the
figure.
- Remove the return spring of the automatic valve
lifter unit and the automatic valve lifter unit and its
end of stroke washer.
ENG - 26
Vespa GTS 125
Vespa GTS 125
Engine
- Loosen the central screw on the tensioner first.
- Remove the two fixings shown in the figure.
- Remove the tensioner with its gasket.
- Remove the internal hex screw and the counterweight shown in the figure.
- Remove the camshaft control pulley with its
washer.
- Remove the command sprocket wheel and the
timing chain.
- Remove the screws indicated in the figure, the
spacer bar and the tensioner slider.
The chain tensioning pad must be removed from
the transmission side. As regards the lower chain
guide pad, it may only be removed after the head
has been removed.
N.B.
IT IS ADVISABLE TO MARK THE CHAIN IN ORDER TO ENSURE THAT THE INITIAL DIRECTION OF ROTATION IS MAINTAINED.
ENG - 27
Engine
Removing the cam shaft
- Remove the two screws and the cam shaft retainer shown in the diagram.
- Remove the cam shaft.
- Remove the pins and the rocker arms from the
flywheel side holes.
N.B.
IN CASE OF NEED, THE HEAD MAY BE REMOVED WITH THE CAMSHAFT, PINS, ROCKING LEVERS AND FIXING BRACKET. THE
HEAD CAN ALSO BE REMOVED WITHOUT REMOVING THE CHAIN AND THE DRIVING
SHAFT CHAIN TIGHTENER.
ENG - 28
Vespa GTS 125
Vespa GTS 125
Engine
Removing the cylinder head
- Remove the spark plug.
- Remove the 2 side fixings shown in the figure.
- Loosen the 4 head-cylinder fastening nuts in two
or three stages and in criss-cross fashion.
- Remove the head, the two centring dowels and
the gasket.
N.B.
IN CASE OF NEED, THE HEAD MAY BE REMOVED WITH THE CAMSHAFT, PINS, ROCKING LEVERS AND FIXING BRACKET. THE
HEAD CAN ALSO BE REMOVED WITHOUT REMOVING THE CHAIN AND THE DRIVING
SHAFT CHAIN TIGHTENER.
Removing the valves
- Using the appropriate tool fitted with an adapter,
remove the cotters, caps, springs and valves.
- Remove the oil guards with the appropriate tool.
- Remove the lower spring supports.
CAUTION
REPLACE THE VALVES IN SUCH A WAY AS
TO RECOGNISE THEIR ORIGINAL POSITION
ON THE HEAD.
Specific tooling
020382Y011 adapter for valve removal tool
020382Y Valve cotters equipped with part 012
removal tool
020306Y Punch for assembling valve seal
rings
Removing the cylinder - piston assy.
- Remove the chain guide pad.
- Pull out the cylinder.
- Remove the cylinder base gasket.
- Remove the two stop rings, the wrist pin and the piston.
- Remove the piston seals.
ENG - 29
Engine
Vespa GTS 125
CAUTION
TO AVOID DAMAGING THE PISTON, SUPPORT IT WHILE REMOVING THE CYLINDER.
N.B.
BE CAREFUL NOT TO DAMAGE THE SEALING RINGS DURING REMOVAL.
ENG - 30
Vespa GTS 125
Engine
Inspecting the small end
- Measure the internal diameter of the small end
using an internal micrometer.
N.B.
REPLACE THE CRANKSHAFT IF THE DIAMETER OF THE ROD SMALL END EXCEEDS THE
STANDARD DIAMETER OR IT SHOWS SIGNS
OF WEAR OR OVERHEATING.
Characteristic
Checking the connecting rod small end: Maximum diameter
15.030 mm
Checking the connecting rod small end: Standard diameter
15 +0.015+0.025 mm
ENG - 31
Engine
Inspecting the wrist pin
- Measure the outer diameter of the gudgeon pin.
- Calculate the coupling clearance between pin
and connecting rod end.
- Measure the capacity diameter on the piston.
- Calculate the piston pin coupling clearance.
- Measure the outside diameter of the piston, perpendicular to the gudgeon pin axis.
- Carry out the measurement as shown in the figure.
41.1 mm (from the crown)
- Using a bore meter, measure the inner cylinder
diameter at three different points according to the
directions shown in the figure.
- Check that the head matching surface exhibits no
deformations or wear.
Maximum admissible displacement: 0.05 mm
- Pistons and cylinders are classified into categories based on their diameter. The coupling is carried out in pairs (A-A, B-B, C-C, D-D).
- The cylinder rectifying operation should be carried out with a surfacing that respects the original
angle.
- The cylinder surface roughness should be 0.9
micron.
- This is indispensable for a good seating of the
sealing rings, which in turn minimises oil consumption and guarantees optimum performance.
- The pistons are oversized due to cylinder rectification and are subdivided into three categories
1st, 2nd, 3rd with 0.2-0.4-0.6 mm oversize. They
are also classified into 4 categories A-A, B-B, CC, D-D.
N.B.
THE PIN HOUSINGS HAVE 2 LUBRICATION
CHANNELS. FOR THIS REASON MEASUREMENT OF THE DIAMETER MUST BE CARRIED
OUT ACCORDING TO THE AXIS OF THE PISTON.
ENG - 32
Vespa GTS 125
Vespa GTS 125
Engine
Characteristic
Pin diameter Standard diameter
56.997 ÷ 57.025
piston diameter
56.945 ÷ 56.973 mm
Pin diameter: Standard clearance
0.015 ÷ 0.029 mm
Pin diameter Standard diameter
14.996 - 15.000 mm
Wrist pin seat on the piston: Standard diameter
15.001 ÷ 15.006 mm
Diameter of the wrist pin seat on the piston:
Standard clearance
0.001 ÷ 0.010 mm
ENG - 33
Engine
Vespa GTS 125
Inspecting the piston
- Carefully clean the seal housings.
- Measure the coupling clearance between the
seal rings and the grooves using suitable sensors,
as shown in the diagram.
- If the clearance is greater than that indicated in
the table, replace the piston.
Inspecting the piston rings
- Alternately insert the three sealing rings into the cylinder, in the area where it retains its original diameter. Using the piston, insert the rings perpendicularly to the cylinder axis.
- Measure the opening (see figure) of the sealing rings using a feeler gauge.
- If any measurements are greater than specified, replace the piston rings.
N.B.
BEFORE REPLACING ONLY THE PISTON RINGS, ENSURE THAT THE CLEARANCE BETWEEN
THE PISTON RINGS AND THE PISTON RING GROOVES, AND BETWEEN THE PISTON AND THE
CYLINDER, IS AS SPECIFIED. IN ANY CASE, NEW PISTON RINGS USED IN COMBINATION WITH
A USED CYLINDER MAY HAVE DIFFERENT BEDDING CONDITIONS THAN THE STANDARD.
Removing the piston
- Install piston and wrist pin onto the connecting rod, aligning the piston arrow the arrow facing towards
the exhaust.
- Fit the pin stop ring onto the appropriate tool.
- With opening in the position indicated on the tool
S = left
ENG - 34
Vespa GTS 125
Engine
D = right
- Place the wrist pin stop ring into position using a punch
- Fit the wrist pin stop using the plug as shown in the figure
CAUTION
USING A HAMMER MIGHT DAMAGE THE STOPS' HOUSING.
N.B.
THE TOOL FOR INSTALLING THE STOP RINGS MUST BE USED MANUALLY.
Specific tooling
020430Y Pin lock fitting tool
Choosing the gasket
- Provisionally fit the piston into the cylinder, without any base gasket.
- Assemble a dial gauge on the specific tool
Support to check piston position 020428Y
- Set the dial gauge to zero placing the tool on a
contrasting surface. Keeping the zero position, assemble the tool on the cylinder and lock it with 2
supplied nuts as shown in the figure.
ENG - 35
Engine
- Rotate the crankshaft until TDC (the inverted
point of the dial gauge rotation)
- Position the dial gauge on the piston as shown in
the figure and measure how much the piston protrudes.
- By means of the table shown in the specifications
chapter identify the cylinder base gasket thickness
to be used for refitting. Correctly identify the cylinder base gasket thickness to keep the correct
compression ratio.
- Remove the specific tool and the cylinder.
N.B.
MEASURE PISTON PROTRUSION.
See also
Slot packing system
ENG - 36
Vespa GTS 125
Vespa GTS 125
Engine
Refitting the piston rings
- Place the oil scraper spring on the piston.
- Refit the oil scraper ring with the join of spring
ends on the opposite side from the ring gap and
the word 'TOP' towards the crown of the piston.
The chamfered side of the oil scraper ring should
always be facing the piston crown.
- Fit the middle piston ring with the identification
letter facing the crown of the piston. In any case,
the step must be facing opposite the piston top.
- Fit the top piston ring with the word 'TOP' or the
reference mark facing the crown of the piston.
- Offset the piston ring gaps on the three rings by
120° to each other as shown in the figure.
- Lubricate the components with engine oil.
N.B.
THE TWO PISTON RINGS ARE MADE WITH A
TAPERED CYLINDRICAL CONTACT CROSSSECTION. THIS IS TO ACHIEVE A BETTER
BEDDING.
Refitting the cylinder
- Insert the cylinder base gasket with the thickness determined above.
- Using the fork support and the piston ring retaining band, refit the cylinder as shown in the figure.
N.B.
BEFORE FITTING THE CYLINDER, CAREFULLY BLOW OUT THE LUBRICATION DUCT AND OIL
THE CYLINDER BARREL.
Specific tooling
020393Y Piston fitting band
020287Y Clamp to assemble piston on cylinder
ENG - 37
Engine
Inspecting the cylinder head
- Using a trued bar and feeler gauge check that the
cylinder head surface is not worn or distorted.
Maximum allowable run-out: 0.05 mm
- Check that the camshaft and the rocker pin capacities exhibit no wear.
- Check that the cylinder head cover surface, the
intake manifold and the exhaust manifold are not
worn.
Characteristic
bearing «A»
Ø 12.000 - 12.018 mm
bearing «B»
Ø 20.000 ÷ 20.021 mm
bearing «C»
Ø 37.000 - 37.025 mm
ENG - 38
Vespa GTS 125
Vespa GTS 125
Engine
Inspecting the timing system components
- Check that the guide shoe and the tensioner shoe
are not worn out.
- Ensure that the camshaft control pulley chain assembly and the sprocket wheel are not worn.
- If you encounter wear, replace the parts or, if the
chain, sprocket wheel and pulley are worn replace
the whole assembly.
- Remove the centre screw with the washer and
the tensioner spring. Check that the one-way
mechanism is not worn.
- Check the condition of the tensioner spring.
- If examples of wear are found, replace the whole
assembly.
Inspecting the valve sealings
- Insert the valves into the cylinder head.
- Alternatively check the intake and exhaust
valves.
- The test is carried out by filling the manifold with
petrol and checking that the head does not ooze
through the valves when these are just pressed
with the fingers.
ENG - 39
Engine
Inspecting the valve housings
- Check the width of the imprint on the valve
seat«V» wear limit max. 1.6 mm.
- Remove any carbon formation from the valve
guides.
- Measure the inside diameter of each valve guide.
- Take the measurement at three different heights
in the rocker arm push direction.
- If the width of the impression on the valve seat or
the diameter of the valve guide exceed the specified limits, replace the cylinder head.
Characteristic
Valve seat wear Intake guide
limit accepted: 5.022
Valve seat wear Intake guide
Standard diameter: 5.000 ÷ 5.012 mm
Valve seat wear Exhaust guide
Accepted limit 5.022
Valve seat wear Exhaust guide
Standard diameter: 5.000 ÷ 5.012 mm
Inspecting the valves
- Measure the diameter of the valve stems in the
three positions indicated in the diagram.
- Calculate the clearance between valve and valve
guide.
- Check that there are no signs of wear on the surface of contact with the articulated register terminal.
- If the checks above give no failures, you can use
the same valves. For best sealing results, it is advisable to grind the valves. Grind the valves gently
with a fine-grained lapping compound. During the
grinding, keep the cylinder head with the valve axes in a horizontal position. This will prevent the
lapping compound residues from penetrating between the valve stem and the guide (see figure).
ENG - 40
Vespa GTS 125
Vespa GTS 125
Engine
CAUTION
TO AVOID SCORING THE FAYING SURFACE,
DO NOT KEEP ROTATING THE VALVE WHEN
NO LAPPING COMPOUND IS LEFT. CAREFULLY WASH THE CYLINDER HEAD AND THE
VALVES WITH A SUITABLE PRODUCT FOR
THE TYPE OF LAPPING COMPOUND BEING
USED.
N.B.
DO NOT CHANGE THE POSITIONS THE
VALVES ARE FITTED IN
Characteristic
Valve check standard length
Outlet: 94.4 mm
Valve check standard length
Inlet: 94.6 mm
Valve check Maximum admissible clearance
Outlet: 0.072 mm
Valve check Maximum admissible clearance
Inlet: 0.062 mm
Valve check standard clearance
Outlet: 0.025 ÷ 0.052 mm
Valve check standard clearance
Inlet: 0.013 ÷ 0.040 mm
Valve check Minimum admissible diameter
Outlet: 4.95 mm
Valve check Minimum admissible diameter
Inlet: 4.96 mm
Valve check Standard diameter:
Inlet: 4.972 ÷ 4.987 mm
Valve check Standard diameter:
Outlet: 4.96 ÷ 4.975 mm
ENG - 41
Engine
Inspecting the springs and half-cones
- Check that the upper spring caps and the cotter
halves show no signs of abnormal wear.
Refitting the valves
- Lubricate the valve guides with engine oil.
- Place the valve spring supports on the head.
- Using the special punch, fit the four valve seals.
- Fit the valves, the springs and the caps. Using
the appropriate tool with adapter, compress the
springs and insert the cotters in their seats.
N.B.
DO NOT CHANGE THE VALVE FITTING POSITION. FIT THE VALVE SPRINGS WITH THE
REFERENCE COLOUR ON COTTER SIDE
(TURNS WITH GREATER PITCH).
Specific tooling
020306Y Punch for assembling valve seal
rings
020382Y Valve cotters equipped with part 012
removal tool
020382Y011 adapter for valve removal tool
ENG - 42
Vespa GTS 125
Vespa GTS 125
Engine
Inspecting the cam shaft
- Inspect the cam shaft for signs of abnormal wear
on the cams.
- Check the cam height.
- Check there is no wear on the cam shaft retaining
plate and its associated groove on the cam shaft.
- If any of the above dimensions are outside the
specified limits, or there are signs of excessive
wear, replace the defective components with new
ones.
- Check there are no signs of wear on the automatic valve-lifter cam, or the end-of stroke roller,
or the rubber buffer on the automatic valve-lifter
retaining cover.
- Check that the valve lifting spring has not yielded.
- Replace any defective or worn components.
- Check the rocker pins do not show signs of wear
or scoring.
- Measure the internal diameter of each rocker
arm.
Check there are no signs of wear on the pad from
contact with the cam and on the jointed adjustment
plate.
Characteristic
Internal rocker arm diameter: Standard diameter
Diameter 12.000 - 12.011 mm
Rocker arm pin diameter: Standard diameter
Diameter 11.977 - 11.985 mm
ENG - 43
Engine
Cam shaft check: Maximum admissible axial
clearance
0.42 mm
Cam shaft check: Standard axial clearance:
0.11 - 0.41 mm
Cam shaft check: Standard height
Outlet: 29.209 mm
Cam shaft check: Standard height
Inlet: 30.285 mm
Cam shaft check: Minimum admissible diameter
Bearing B diameter: 19.950 mm
Cam shaft check: Minimum admissible diameter
Bearing A Ø: 36.94 mm
Cam shaft check: Standard diameter
Bearing B diameter: 19.959 ÷ 19.98 mm
Cam shaft check: Standard diameter
Bearing A Ø: 36.95 ÷ 36.975 mm
Refitting the head and timing system components
Assemble the lower timing chain sprocket wheel
on the crankshaft, with the chamfer facing the insertion side.
- Loop the timing chain around the sprocket on the
crankshaft.
- Fit the chain tensioner slider from the cylinder
head side.
- Fit the spacer and the screw fastener.
- Tighten the screws to the prescribed torque.
Locking torques (N*m)
Slider screw 10 ÷ 14 Nm
ENG - 44
Vespa GTS 125
Vespa GTS 125
Engine
Fit the pins and rocking levers.
- Lubricate the two rocking levers through the
holes at the top.
- Lubricate the 2 bearings and insert the cam shaft
in the cylinder head with the cams corresponding
to the rockers.
- Insert the retention plate and tighten the two
screws shown in the figure to the prescribed torque.
Locking torques (N*m)
Plate screws 4 ÷ 6 Nm
Insert the spacer on the cam shaft.
- Rotate the engine so that the piston is at top dead
centre, using the reference marks on the flywheel
and the crankcase.
- Holding this position insert the chain on the camshaft control pulley.
- Insert the pulley on the cam shaft while keeping
the reference 4V in correspondence with the reference mark on the head.
- Assemble the counterweight with the corresponding fixing screw and tighten to the prescribed
torque.
Locking torques (N*m)
Counterweight screw 7 ÷ 8.5
Fit the end-of stroke ring on the valve-lifting mass
and fit the automatic valve-lifting cam to the camshaft.
N.B.
LUBRICATE WITH GREASE THE END-OFSTROKE RING IN ORDER TO AVOID ACCIDENTAL LEAKS THAT MAY FALL INTO THE
ENGINE. ASSEMBLE THE AUTOMATIC
VALVE-LIFTER RETURN SPRING. DURING
THIS OPERATION THE SPRING MUST BE LOADED AT APPROXIMATELY 180°.
ENG - 45
Vespa GTS 125
Engine
Assemble the limiting bell using the counterweight
fixing screw as a reference.
- Tighten the clamping screw to the prescribed torque.
Locking torques (N*m)
Limiting bell screw 11 ÷ 15 Nm
Set the tensioner cursor to the rest position.
- Fit the chain tensioner on the cylinder, using a
new gasket, and tight the two screws to the prescribed torque.
Insert the chain tensioning screw, together with the
spring and washer, tightening it to the prescribed
torque.
Locking torques (N*m)
Tensioner screws 11 ÷ 13 Tensioner cover 5 ÷
6 Nm
Adjust valve clearance
- Fit the spark plug.
Electrode distance 0.8 mm
Locking torques (N*m)
Spark plug 12 ÷ 14
Refit the cylinder head cover, tightening the 5 screws to the prescribed torque. Make sure the gasket
is positioned properly.
Remove the flywheel cover completely as already described in the flywheel chapter.
- Reassemble the oil pump control, the chain compartment cover, the by-pass and the oil sump as
described in the lubrication chapter.
- Reassemble the driving pulley, the belt and the transmission cover as described in the transmission
chapter.
Locking torques (N*m)
Tappet cover screws 6 - 7 Nm
TIMING SYSTEM COMPONENTS ASSEMBLY
Name
Tappet cover screws
Spark plug
Tensioner cover
Tensioner screws
Limiting bell screw
ENG - 46
Torque in Nm
6 - 7 Nm
12 ÷ 14
5 ÷ 6 Nm
11 ÷ 13
11 ÷ 15 Nm
Vespa GTS 125
Name
Counterweight screw
Plate screws
Slider screw
Engine
Torque in Nm
7 ÷ 8.5
4 ÷ 6 Nm
10 ÷ 14 Nm
- Fit the timing chain guide pad.
- Insert the centring dowel between the cylinder
head to the cylinder, fit the cylinder head gasket
and the cylinder head.
- Lubricate the stud bolt threading.
- Tighten up the nuts to a pre-torque of 7±1 N·m
- Rotate by a 180° angle (2 rotations of 90° each)
- To carry out the operations described above, follow the tightening sequence in the figure.
- Fit the two screws on the outside of the timing
chain side and tighten them to the prescribed torque.
N.B.
BEFORE INSTALLING THE HEAD, MAKE
SURE THAT THE LUBRICATION CHANNEL IS
CLEAN USING A COMPRESSED AIR JET.
Locking torques (N*m)
Timing chain tensioner support screw 11 ÷ 13
ENG - 47
Engine
Vespa GTS 125
Refitting the rocker-arms cover
- Refit the cylinder head cover, tightening the 5
clamping screws to the prescribed torque.
- Make sure the gasket is positioned properly.
Locking torques (N*m)
Tappet cover screws 6 - 7 Nm
Refitting the intake manifold
Fit the intake manifold and do up the three screws.
N.B.
USE COMMERCIALLY AVAILABLE INSERTS
AND INSERT HOLDERS FOR THE SPECIAL
SCREWS FOR 125 CM³ MODELS.
Crankcase - crankshaft
Splitting the crankcase halves
Precautionary remove the following units:
transmission cover, driving pulley, driven pulley and belt, rear hub cover, gears, bearings and oil seals
as described in the transmission chapter.
-Remove the oil sump, the by-pass, the chain compartment cover and the oil pump as in the lubrication chapter.
- Remove the flywheel cover together with the water pump, the flywheel and the stator as described in
the magneto flywheel chapter.
- Remove the oil filter and the oil pressure switch.
- Remove the cylinder/piston/head unit as described in the cylinder head timing system chapter.
- Remove the two retainers indicated in the figure and the starter motor.
ENG - 48
Vespa GTS 125
Engine
Before opening the engine crankcase, it is advisable to check axial clearance of the crankshaft. To
do this, use a plate and a support with appropriate
tool dial gauge.
Higher clearances are signs of wear on the supporting surfaces of the crankshaft casing.
Standard clearance: 0.15 ÷ 0.40 mm
Remove the 11 coupling screws to the crankcase.
- Separate the crankcase while keeping the crankshaft in one of the two halves of the crankcase.
Remove the crankshaft.
CAUTION
KEEP THE CRANKSHAFT IN ONE OF THE TWO
HALVES OF THE CRANKCASE WHEN SEPARATING IT. IF YOU FAIL TO DO THIS, THE
CRANKSHAFT MIGHT ACCIDENTALLY FALL.
- Remove the coupling gasket of the crankcase
halves.
- Remove the two screws and the internal cover
shown in the diagram.
CAUTION
WHILE OPENING THE CRANKCASES AND REMOVING THE DRIVING SHAFT, CHECK THAT
THE THREADED SHAFT ENDS DO NOT INTERFERE WITH THE MAIN BUSHINGS. FAILURE
TO OBSERVE THIS PRECAUTION CAN DAMAGE THE MAIN BUSHINGS.
- Remove the oil guard on the flywheel side.
- Remove the oil filter fitting shown in the diagram
ENG - 49
Engine
Vespa GTS 125
Fitting clearance
Connecting rod axial clearance 0.20 - 0.50
Check the radial clearance on the connecting rod.
Standard clearance: 0.036 ÷ 0.054 mm
-Check the surfaces that limit the axial free-play
are not scored and measure the width of the crankshaft between these surfaces, as shown in the
diagram.
Standard dimensions:
55.75 ÷ 55.90 mm
N.B.
WHEN MEASURING THE WIDTH OF THE
CRANKSHAFT, MAKE SURE THAT THE MEASUREMENTS ARE NOT MODIFIED BY THE RADIUSES OF FITTINGS WITH THE CRANKSHAFT
BEARINGS.
If the axial clearance between crankshaft and crankcase exceeds the standard and the crankshaft does
not have any defect, the problem must be due to either excessive wear or wrong machining on the
engine crankcase.
Check the diameters of both bearings of the crankshaft according to the axes and surfaces shown in
the figure. The half-shafts are classified in two categories Cat. 1 and Cat. 2 as shown the chart
below.
Characteristic
Standard diameter - Category 2
29.004 ÷ 29.010
Standard diameter - Category 1
28.994 ÷ 29.000
ENG - 50
Vespa GTS 125
Engine
The crankshaft can be reused when the width is within the standard values and the surfaces show no
signs of scoring.
Inspecting the crankshaft alignment
To install the drive shaft on the support and to
measure the misalignment in the 4 points indicated
in figure.
- Check that the driving shaft cone, the tab seat,
the oil seal capacity, the toothed gear and the
threaded tangs are in good working order.
- In case of failures, replace the crankshaft.
The connecting rod head bushings cannot be replaced. For the same reason, the connecting rod
may not be replaced and, when cleaning the
crankshaft, be very careful that no impurities get in
through the shaft's lubrication holes.
In order to prevent damaging the connecting rod
bushings, do not attempt cleaning the lubrication
duct with compressed air.
- Make sure that the 2 caps on the crankpin are
properly fitted.
- A wrong installation of a cap can seriously affect
the bushing lubrication pressure.
N.B.
THE MAIN BEARINGS ARE NOT GRINDABLE
Specific tooling
020074Y Support base for checking crankshaft
alignment
Characteristic
Off-line maximum admitted
A = 0.15 mm
B = 0.01 mm
C = 0.01 mm
D = 0.10 mm
Measure the capacity of both axes X-Y
Specific tooling
020074Y Support base for checking crankshaft alignment
ENG - 51
Vespa GTS 125
Engine
CRANKSHAFT ALIGNMENT
Titolo
Durata/Valore
Crankshaft alignment
Inspecting the crankcase halves
- Before proceeding to check the crankcase
halves, thoroughly clean the all surfaces and oil
ducts.
- On the transmission-side crankcase half, take
particular care when handling the oil pump compartment and the oil ducts, the by-pass duct, the
main bushings and the cooling jet on the transmission side (see diagram).
- Take particular care, also, that there are no signs
wear in the oil by-pass valve housing (see Chapter
Lubrication), as this could prevent a good seal in
the valve, which regulates the oil pressure.
- On the flywheel side crankcase half, take particular care cleaning the oil ducts for the main bushings, the oil duct for the jet that lubricates the
ENG - 52
Testo Breve (< 4000
car.)
Indirizzo Immagine
Vespa GTS 125
Engine
cylinder head and the oil drainage duct at the flywheel side oil seal.
- Inspect the coupling surfaces on the crankcase
halves for scratches or deformation, taking particular care with the cylinder/crankcase surfaces and
the crankcase halves surfaces.
- Defects in the crankcase coupling gasket between the crankcase halves or the mating surfaces
shown in the diagram, could cause a drop in the
oil pressure lubricating the main bearings and connection rod.
- Check the main bearing seats that limit axial
clearance in the crankshaft show no signs of wear.
The dimension between these seats is measured
by way of the procedure described previously for
measuring the crankshaft axial clearance and dimensions.
N.B.
THE JET IS FED THROUGH THE MAIN BUSHINGS. PROPER OPERATION OF THIS COMPONENT IMPROVES THE PISTON TOP COOLING.
CLOGGING HAS EFFECTS THAT ARE DIFFICULT TO DETECT (PISTON TEMPERATURE
INCREASE). FAILURE OR LEAK CAN CONSIDERABLY DECREASE THE MAIN BUSHING
AND CONNECTING ROD LUBRICATION PRESSURE.
N.B.
THE HEAD LUBRICATION CHANNEL IS PROVIDED WITH A SHUTTER JET; THIS GIVES A
"LOW PRESSURE" HEAD LUBRICATION; THIS
CHOICE WAS MADE TO REDUCE THE OIL
TEMPERATURE IN THE SUMP. THE JET
CLOGGING IMPAIRS THE HEAD LUBRICATION AND THE TIMING MECHANISMS. A JET
FAILURE CAUSES A DECREASE OF THE MAIN
BUSHING AND CONNECTING ROD LUBRICATION PRESSURE.
ENG - 53
Engine
Inspecting the crankshaft plain bearings
-T
o obtain a good bushing lubrication it is necessary
to have both an optimal lubricating pressure (3,2
bar) and a good oil flow rate; the bushings must be
correctly positioned so as not to obstruct the oil
supply channels.
- The main bushings are comprised of two halfbearings, one with holes and channels for lubrication whereas the other is solid.
- The solid half-bearing is intended to stand the
thrusts caused by combustion, and for this reason
it is arranged opposite the cylinder.
- To prevent obstructions in the oil feeding channels, the matching surface of the two half-bearings
must be perfectly perpendicular to the cylinder axis, as shown in the figure.
- The oil feeding channel section is also affected
by the bushings driving depth compared with the
crankshaft axial clearance of the limiting surface.
- Check the inside diameter of the main bushings
in the three directions indicated in the diagram.
- Repeat the measurements for the other bushing
half. see diagram.
- There are three crankcase versions: with RED
main bushings, with BLUE main bushings and with
YELLOW main bushings.
- There is only one type of main bushing housing
hole in the crankcase
The standard bushing diameter after driving is variable on the basis of a coupling selection.
- The bushing housings in the crankcase are available in two categories, Cat. 1 and Cat. 2, as are
the crankshafts.
- The main bushings are available in three thickness categories, identified by colour markings, as
shown in the table below.
ENG - 54
Vespa GTS 125
Vespa GTS 125
Engine
TYPE
IDENTIFICATION
A
RED
B
BLUE
C
YELLOW
Type "A" Type "B" Type "C"
- RED
- BLUE
- YELLOW
Main half-
1.970 ÷
1.9703 ÷
1.976 ÷
bearing
1.973
1.976
1.979
Bush-
Crank-
Internal bush-
Possible
ing cat-
case
ing diameter
fitting
egory
halves
after fitting
category
A
1
29.025 ÷
Original
29.040
B
1
2
29.019 ÷
Original
29.034
and spare
29.028 ÷
29.043
C
2
29.022 ÷
Original
29.037
Match the shaft with two category 1 crank webs
with the category 1 crankcase (or cat. 2 with cat.
2) Furthermore a replacement crankcase cannot
be matched with a crankshaft with mixed categories. The replacement crankshaft has half-shafts
of the same category.
Crankcase
Engine half-
Bushing
halves
shaft
Cat. 1
Cat. 1
B
Cat. 2
Cat. 2
B
Cat. 1
Cat. 2
A
Cat. 2
Cat. 1
C
N.B.
TO KEEP THIS POSITION OF THE BUSHINGS
ON THE CRANKCASE, FITTING IS FORCED ON
STEEL RINGS INSERTED IN THE CASTING OF
BOTH CRANKCASE HALVES.
ENG - 55
Engine
N.B.
DO NOT TAKE THE MEASUREMENT ON THE
TWO HALF-SHELL COUPLING SURFACE
SINCE THE ENDS ARE RELIEVED TO ALLOW
BENDING DURING THE DRIVING OPERATION.
N.B.
CRANKCASES FOR REPLACEMENTS ARE
SELECTED WITH CRANKCASE HALVES OF
THE SAME CATEGORY AND ARE FITTED
WITH CATEGORY B BUSHINGS (BLUE)
Characteristic
Standard driving depth
1.35 ÷ 1.6
Diameter of crankcase without bushing
32.953 ÷ 32.963
Refitting the crankcase halves
Lubrication
Conceptual diagrams
LUBRICATION CIRCUIT
ENG - 56
Vespa GTS 125
Vespa GTS 125
Engine
ENG - 57
Engine
Oil pressure check
- After removing the flywheel cover as described
in the "Flywheel" chapter, remove the electrical
connexion of the minimum oil pressure switch and
then remove the switch.
- With the engine idling at 1650 rpm and the oil
temperature at ~90°C, check that the oil pressure
is between 0.5 ÷ 1.2 atm.
- With the engine idling at 6000 rpm and the oil
temperature at ~90°C, check that the oil pressure
is between 3.2 ÷ 4.2 atm.
- Remove the appropriate tools once the measurement is complete, refit the oil pressure switch
and washer, tightening it to the specified torque
and fit the fan cover.
- If the oil pressure is outside the specified limits,
in the following order, check: the oil filter, the oil
by-pass valve, the oil pump and the crankshaft
seals.
N.B.
THE CHECK MUST BE CARRIED OUT WITH
OIL AT THE CORRECT LEVEL AND WITH AN
OIL FILTER IN GOOD CONDITION.
Characteristic
Oil pressure
Minimum pressure admitted at 6000 rpm: 3.2 atm.
Locking torques (N*m)
Minimum oil pressure sensor 12 ÷ 14
ENG - 58
Vespa GTS 125
Vespa GTS 125
Engine
Crankshaft oil seals
Refitting
- Fit the internal bulkhead by locking the two
screws to the prescribed torque.
- Fit the oil filter fitting and tighten it to the specified
torque.
- Place a new gasket on one of the crankcase
halves, preferably on the transmission side, together with the locating dowels.
- Lubricate the main bushings and insert the crankshaft in the transmission side crankcase half.
- Reassemble the two crankcase halves.
- Fit the 11 screws and tighten them to the prescribed torque.
- Lubricate the flywheel oil seal.
- Using the appropriate tool, assemble the oil seal.
- Fit a new O-ring on the pre-filter and lubricate it.
- Insert the filter on the engine with the relative cap.
Tighten to the specified torque.
N.B.
FAILURE TO USE THE SPECIFIC TOOL CAN
RESULT IN AN INCORRECT DEPTH POSITION
AND AS A CONSEQUENCE IN INADEQUATE
OIL SEALING.
Specific tooling
020425Y Punch for flywheel-side oil seal
Locking torques (N*m)
Internal engine crankcase bulkhead (transmission-side half shaft) screws 4 ÷ 6 Oil filter on
crankcase fitting 27 ÷ 33 Engine-crankcase
coupling screws 11 ÷ 13 Engine oil drainage
plug/mesh filter 24 ÷ 30
ENG - 59
Engine
Oil pump
- Check there are no signs of wear on the oil pump
shaft or body.
- Check there are no signs of scoring or wear on
the oil pump cover.
- If you detect non-conforming measurements or
scoring, replace the faulty parts or the unit.
- Fit the pump cover in the position that permits the
crankcase fixing screws to be aligned.
- Make sure the gasket is positioned properly and
refit the pump on the engine crankcase. The pump
can only be fitted in one position. - Tighten the
screws to the prescribed torque.
- Fit the sprocket wheel with a new O-ring.
- Fit the chain.
- Fit the central screw and the belleville washer.
Tighten to the prescribed torque.
- Fit the oil pump cover by tightening the two
screws to the prescribed torque.
N.B.
FIT THE BELLEVILLE WASHER SO THAT ITS
OUTER RIM TOUCHES THE PULLEY. MAKE
SURE THAT THE PUMP TURNS FREELY.
Locking torques (N*m)
Screws fixing oil pump to the crankcase 5 - 6
Oil pump control crown screw 10 ÷ 14 Oil pump
cover screws 0.7 ÷ 0.9
Removing the oil sump
- Remove the oil filler plug, the transmission cover,
the complete driving pulley assembly with belt and
the sprocket wheel, as described in the "Transmission" chapter.
- Drain the oil as described previously.
- Remove the seven screws, shown in the diagram, and the two rear brake fluid pipe fixing
brackets.
- Remove the screw, the by-pass piston, the gasket and centring dowels shown in the figure.
ENG - 60
Vespa GTS 125
Vespa GTS 125
Engine
Inspecting the by-pass valve
- Check the unloaded spring length.
- Check that the small piston is not scored.
- Ensure that it slides freely on the crankcase and that it guarantees a good seal.
- If not, eliminate any impurities or replace defective parts.
Characteristic
By-pass check up: Standard length
54.2 mm
Refitting the oil sump
- Refit the by-pass valve plunger in its housing.
- Insert the pressure-regulating spring.
- Fit a new sump seal.
- Refit the two centring dowels.
- Refit the sump, taking care to locate the spring in
the appropriate recess machined into the inside of
the sump.
- Refit the rear brake cable brackets and the
screws in the reverse order from which they were
removed.
- Tighten the screws to the prescribed torque.
- Refit the driving pulley assembly, the drive belt,
the sprocket wheel and the transmission cover, as
described in the "Transmissions" chapter.
- When testing the lubrication system, refer to
chapter "Crankcase and Crankshaft", regardENG - 61
Engine
ing lubrication of the crankshaft and connecting rod
Locking torques (N*m)
Oil sump screws 10 ÷ 14
SAS valve
Inspecting the one-way valve
- Remove the SAS valve.
- Provisionally assemble the rubber coupling of the
SAS valve outlet to ensure tightness.
- Connect the MITYVAC vacuum pump to the rubber coupling as shown in the photograph.
- Set the pump to the low-pressure position (VACUUM).
- Operate the pump slowly.
- Check that the one way valve allows the air to
pass through causing a slight vibration.
- Switch the pump to pressure mode (PRESSURE).
- Operate the pump slowly and check if there is an
increase of pressure. A small leakage is considered to be normal.
If anomalies are detected, replace the pump.
N.B.
A MALFUNCTIONING ONE-WAY VALVE CAN
RESULT IN RUBBER COUPLING AND FILTER
OVERHEATING
N.B.
ABSENCE OF VIBRATION INDICATES INEFFICIENT SEALING
Specific tooling
020329Y MityVac vacuum-operated pump
ENG - 62
Vespa GTS 125
Vespa GTS 125
Engine
Inspecting the cut-off
- Remove the SAS valve.
- Connect the MITYVAC pump in low-pressure
mode (VACUUM) to the CUT-OFF valve vacuum
intake.
- Apply a vacuum value higher than 0.5 BAR.
- Check that this value is kept all the time.
- If a worn seal is detected, replace it.
- With a "T" bypass and flexible rubber hoses make
a parallel connection between the rubber coupling
and the vacuum intake of the CUT-OFF valve.
- Connect the bypass to the MITYVAC pump.
- Set the pump set to the low-pressure mode
(VACUUM).
- Using a pair of long flat pliers, choke the rubber
hose next to the valve.
- Operate the pump until vacuum is higher than 0.5
BAR.
- Release the hose and check how the vacuum reacts. - Under normal functioning conditions the
vacuum undergoes a slight fall and then readjusts.
There follows a slow and continuous loss of depression up to approximately 0.4 BAR. At this point
the valve opens and the depression is suddenly
set to zero.
Lack of tightness or the fact that the valve opens
at different vacuum values should be regarded as
anomalies. In this case, replace it.
N.B.
LACK OF TIGHTNESS IN THE CUT-OFF VALVE
RESULTS IN EXHAUST NOISE (EXPLOSIONS
IN THE MUFFLER). INCORRECT CUT-OFF
VALVE CALIBRATION CAN RESULT IN CATALYTIC CONVERTER MALFUNCTIONING
N.B.
A FAULTY CUT-OFF VALVE DIAPHRAGM, BESIDES JEOPARDISING THE CORRECT OPERATION OF THE CUT-OFF VALVE, ALSO DAMAGES IDLE FUNCTIONING
Specific tooling
ENG - 63
Engine
020329Y MityVac vacuum-operated pump
Fuel supply
- To clean the filtering element proceed as follows:
remove the 4 filter cover fixing screws indicated in
the figure; remove the cover and take out the paper filtering element, clean with compressed air
and refit.
- Make sure the filtering element is in the correct
position.
- Check that the air passage sections are not damaged or deformed.
- Check the correct sealing of the coupling between the filter housing and the cover.
N.B.
FAILURE TO OBSERVE THESE INSTRUCTIONS MAY RESULT IN WRONG VACUUM INSIDE THE FILTER HOUSING, WHICH IN TURN
MAY PRODUCE VARIATIONS IN CARBURETION.
Removing the carburettor
Kehin
- To detach the carburettor from the engine, it is
necessary to move the air filter and remove the
transmission throttle control, the automatic starter
connection, the clamps anchoring the carburettor
to the filter housing and to the inlet manifold, the
air delivery pipe to the diaphragm, and the intake
fitting.
- Take out the carburettor and rotate it so as to
remove the screw with the water joint and the
pipes.
N.B.
THIS LAST OPERATION IS NECESSARY SO
AS NO TO EMPTY THE COOLING SYSTEM.
ENG - 64
Vespa GTS 125
Vespa GTS 125
Engine
- Remove the protection, the bracket and the starter acting on the screw shown in the figure.
- Remove the 2 screws and the starter support with
the gasket.
- Remove the clamp and cover with the airing filter
of the diaphragm chamber.
- Remove the 4 fixing screws shown in the figure
and the vacuum chamber cover.
WARNING
DURING THE REMOVAL OF THE CARBURETTOR COVER TAKE SPECIAL CARE NOT TO
RELEASE THE SPRING ACCIDENTALLY.
ENG - 65
Engine
- Remove the vacuum valve together with the diaphragm.
- Unscrew the bayonet joint 1/8 of a turn and remove, take out the spring and vacuum valve needle
- Remove the 4 screws indicated in the figure.
ENG - 66
Vespa GTS 125
Vespa GTS 125
Engine
- Remove the chamber with the accelerating
pump, its control and gasket.
- Remove the oil pump seal.
- Remove the intake and outlet valves of the intake
pump from the tank
N.B.
CAUTION, THE ACCELERATION PUMP
VALVES ARE MADE UP OF NOZZLES, SPRING
AND BALL.
N.B.
AVOID REMOVING THE PISTON OF THE PUMP
AND ITS CONTROL.
Adequately support the carburettor and using a
rod and hammer remove the float pin acting from
the throttle control side.
- Remove the float and the plunger.
- Remove the maximum nozzle
ENG - 67
Engine
-Remove the maximum nozzle.
-Remove diffuser.
ENG - 68
Vespa GTS 125
Vespa GTS 125
Engine
- Remove the sprayer.
N.B.
WHEN CLEANING THE CARBURETTOR BODY
REMOVE THE SPRAYER TO AVOID LOSING
PARTS. IF THE SPRAYER IS FORCED IN ITS
HOUSING DO NOT ATTEMPT TO REMOVE IT
AS THIS WILL ONLY DAMAGE IT.
-Remove the minimum nozzle.
- Remove the minimum flow set screw and the
spring.
CAUTION
DO NOT ATTEMPT REMOVING PARTS EMBEDDED IN THE CARBURETTOR BODY SUCH
AS: FUEL SUPPLY PIPE, PLUNGER HOUSING,
STARTER NOZZLE, PIT COVER FOR PROGRESSIONS AND INLET NOZZLE, MINIMUM
AND MAXIMUM AIR GAUGE, THROTTLE
VALVE CONTROL SHAFT. DO NOT REMOVE
THROTTLE-SHAFT CONNECTION SCREWS.
THE FIXING SCREWS ARE CAULKED AFTER
ASSEMBLY AND THEIR REMOVAL DAMAGES
THE SHAFT.
Refitting the carburettor
ENG - 69
Engine
Vespa GTS 125
Kehin
- Before refitting, wash the carburettor body accurately with petrol and compressed air.
- Pay special attention to the fuel supply pipe and
the plunger seat.
- For maximum circuit, check the air adjustment is
correct as shown in the figure.
- For the minimum circuit, make sure the following
points are properly cleaned: air gauging, outlet
section controlled by flow screw, progression
holes near the throttle valve.
- For the starter circuit, blow the connection pipe properly with the jet. This is necessary because the
nozzle support hides other inaccessible internal calibrations.
- Blow the intake nozzle properly.
N.B.
THE ACCELERATION NOZZLE OUTLET IS EXTREMELY SMALL AND IS ORIENTED TO THE
THROTTLE VALVE. NOZZLE INCORRECT ORIENTATION RESULTS IN INADEQUATE SPRAYING.
- Check that there are 5 closing ball joints for the operating pipes on the carburettor body.
ENG - 70
Vespa GTS 125
Engine
- Check that the coupling surfaces, the tank and the diaphragm are not dented.
-Check that the depression valve housing pipe is not scratched.
- Check that the throttle valve and the shaft do not show abnormal wear.
- Check that the plunger seat does not show abnormal wear.
- Replace the carburettor in case of irregularities.
- Check that the return spring of the accelerating pump rocking lever is not deformed by over-stretching.
N.B.
TO AVOID DAMAGES, DO NOT INTRODUCE METAL OBJECTS IN THE ADJUSTED SECTIONS.
- Wash and blow the minimum nozzle properly and
reassemble it.
- Properly wash and blow the components of the
sprayer maximum circuit, the diffuser and the nozzle.
- Introduce the sprayer in the carburettor body with
the shortest cylindrical part directed to the diffuser.
- Assemble the diffuser making sure the sprayer is
being adequately inserted and lock it.
-Assemble the maximum nozzle.
- Check that the tapered pin does not show signs
of wear on the sealing surfaces of the shock absorber pin and the return clamp.
- Replace the rod if worn out.
- Check that the float is not worn on the pin housing or on the contact plate with the plunger and that
there are no fuel infiltration.
- Replace it in case of anomalies.
ENG - 71
Vespa GTS 125
Engine
- Introduce the float with the rod on the fuel feeding tube side.
N.B.
INTRODUCE THE RETURN SPRING ON THE FLOAT PLATE ADEQUATELY
- Remove the drainage screw from the tank, wash
and blow it properly and make sure the acceleration pump pipes are clean.
- Operate the acceleration pump piston repeatedly
and blow with compressed air.
- Reassemble the acceleration pump valves following this order:
INTAKE VALVE (A)
•
Spring
•
Ball
•
Nozzle
IN VALVE (M)
•
Ball
•
Spring
•
Nozzle
N.B.
THE IN VALVE NOZZLE, CORRESPONDING
TO THE ACCELERATION PUMP, IS MILLED.
-Check the screw tightness introducing a small
amount of fuel in the tank.
- Assemble a new gasket on the tank.
- Assemble the tank on the carburettor body fastening the 4 screws.
- Check that the control roller is free to rotate in its
own seat.
N.B.
MAKE SURE THE TANK GASKET IS CORRECTLY INTRODUCED
N.B.
AVOID DEFORMING THE ACCELERATION
PUMP CONTROL ROCKING LEVER.
ENG - 72
Vespa GTS 125
Engine
- Wash and blow the flow screw properly.
- Check that screw is not deformed and/or rusty.
- Assemble the spring on the screw.
- Screw the flow screw on the carburettor body.
- The screw final position should be determined by an exhaust fume analysis.
- Adjust the carburettor by turning the screw twice from the close position.
Level check
Kehin
- Place the carburettor inclined as shown in the
figure.
- Check that the float reference is parallel to the tank coupling surface
- If different positions are detected, change the plunger control metal plate direction to obtain the position
described above.
Inspecting the valve and needle
ENG - 73
Engine
Kehin
- Check that the tapered pin of the vacuum valve
does not show wear.
- Check that the depression valve does not show
threads on the external surfaces.
- Check that the vacuum intake hole is not clogged.
- Check that the diaphragm is not damaged or has
hardened, otherwise replacement the whole valve.
- Insert the tapered pin into the vacuum valve
housing.
- Reassemble the vacuum valve on the carburettor
body taking care that the tapered pin is inserted
into the sprayer.
N.B.
THE VALVE CAN BE INSERTED IN ONLY ONE
POSSIBLE POSITION.
- Reassemble the spring with the pin lock.
- Remove the cover of the vacuum chamber being
careful to correctly insert the spring in its place on
the cover.
- Tighten the screws.
ENG - 74
Vespa GTS 125
Vespa GTS 125
Engine
- Wash and blow dry the filter sponge of the ambient pressure intake.
- Reassemble the filter with its clamp.
- Wash and blow dry the starter support.
Assemble a new gasket on the carburettor body
and tighten the 2 fixing screws.
Inspecting the automatic choke device
ENG - 75
Engine
Kehin
- Check that the automatic starter piston is not deformed or rusty.
- Check that the piston slides freely from the seat
to the support.
- Check that the piston sealing gasket is not deformed.
- The starter must be more or less functional depending on the ambient temperature.
- Measure the protrusion of the piston as shown in
the figure and check its corresponding value.
- Make sure that the starter is adjusted for the ambient temperature.
- The starter should disconnect progressively by
means of electrical heating.
- Check the starter resistance when adjusted to the
ambient temperature.
With a 12V battery power the automatic starter and
check that the piston protrudes as much as possible.
- The correct warm up time depends on the ambient temperature.
- If protrusion, resistance or timing values are different from the ones prescribed, replace the starter.
- Assemble the starter to the carburettor being
careful to position the O-Ring correctly, insert the
plate with the machined side contacting the starter,
tighten the fixing screws.
- Position the starter as shown in the figure.
- Assemble the protection casing.
N.B.
TO CARRY OUT THIS CHECK PAY SPECIAL
ATTENTION NOT TO GENERATE SHORT CIRCUITS USE A CABLE SECTION WITH A TERMINAL SUITABLE TO BE CONNECTED TO THE
STARTER.
Characteristic
Starter pin travel
ENG - 76
Vespa GTS 125
Vespa GTS 125
Engine
10
Starter device resistance
~ 20 Ω
Adjusting the idle
- The engine does not require frequent idle speed
adjustments, but it is essential to strictly follow certain rules when adjusting the idle speed.
- Before adjusting the carburettor make sure to respect the lubrication requirements, valve clearance, and complying timing, spark plug should be
in optimum conditions, air filter clean and sealed,
and the exhaust system tight.
- Warm up the engine by running it at least 5 minutes at approximately 50 kph.
- Connect a millimetre thermometer (020331y) on
the sump, using a cover with oil expressly prepared for probes.
- Start the engine and before adjusting the idle
speed, make sure that the oil temperature is between 70÷80 °C.
- Using the rpm indicator of the analyser or an independent one (020332y), adjust the idle set
screw until 1600 ÷ 1700 rpm is obtained.
N.B.
THE WASTED SPARK IGNITION SYSTEM OFFERS REMARKABLE POWER. READINGS
MAY NOT BE ACCURATE IF INADEQUATE
RPM INDICATORS ARE USED. CORRECT
COUPLING OF THE RPM INDICATOR WILL BE
INDICATED WHEN IT CAN READ RPM OVER
6000 ÷ 8000
ENG - 77
Engine
ENG - 78
Vespa GTS 125
INDEX OF TOPICS
SUSPENSIONS
SUSP
Suspensions
Vespa GTS 125
This section is devoted to operations that can be carried out on the suspension.
Front
Removing the front wheel
- Remove the 5 fixing screws indicated in the photograph.
Locking torques (N*m)
Wheel fixing screw 20 ÷ 25
Front wheel hub overhaul
- Remove the ball bearing seeger ring indicated in
the photograph
Extract the ball bearing using the specific tool
Specific tooling
001467Y014 Pliers to extract ø 15-mm bearings
001467Y017 Bell for bearings, outside Ø 39 mm
SUSP - 2
Vespa GTS 125
Suspensions
- Remove the oil seal on the roller bearing side
using a screwdriver.
- Remove the roller bearing using the specific tool
Specific tooling
020376Y Adaptor handle
020456Y Ø 24 mm adaptor
020363Y 20 mm guide
- Heat the roller bearing seat with a heat gun
- Use the specific tool to introduce and push the
bearing until it stops, with the shielded side facing
out
- Refit the ball bearing locking seeger ring
Specific tooling
020151Y Air heater
020376Y Adaptor handle
020359Y 42x47-mm adaptor
020412Y 15 mm guide
- Use the specific tool to fit and push the roller casing until it stops
- Refit the oil seal on the roller bearing side
- Lubricate the area between the roller bearing and
the ball bearing
Specific tooling
020038Y Punch
Recommended products
AGIP GREASE MU3 Grease for odometer
transmission gear case
SUSP - 3
Suspensions
Vespa GTS 125
Soap-based lithium grease with NLGI 3; ISO-LXBCHA3, DIN K3K-20
Refitting the front wheel
- To refit, carry out the removal operations but in reverse order and comply with the specified locking
torque.
Locking torques (N*m)
Wheel fixing screw 20 ÷ 25
Steering column
Removal
- Remove the front wheel
- Remove the brake calliper
- Loosen the screw fixing the odometer cable plate
and take out the cable.
- Remove the suspension arm housing by unscrewing the three screws indicated in the photograph.
SUSP - 4
Vespa GTS 125
Suspensions
- Remove the retainer fixing the odometer cable to
the mudguard indicated in the photograph
- Remove the retainer fixing the brake piping to the
front shock absorber upper plate
- Remove the retainer fixing the brake piping to the
suspension arm
SUSP - 5
Suspensions
- Pre-loosen the 3 nuts fixing the mudguard to the
suspension
- Remove the rear handlebar cover.
- Remove the screw fixing the handlebar to the
steering tube
- Tilt the handlebar towards the shield back plate
being careful not to scratch the plastic parts
- Remove the steering tube ring nut cover
- Use a specific tool to remove the counter-ring nut,
the spacer washer and the ring nut of the upper
disk of the fifth wheel fitting
- Slide off the steering tube and remove permanently the mudguard from the suspension
Specific tooling
020055Y Wrench for steering tube ring nut
SUSP - 6
Vespa GTS 125
Vespa GTS 125
Suspensions
To refit, carry out the removal operations but in reverse order; grease the fifth wheel fittings and tighten
to the prescribed torques.
Locking torques (N*m)
Upper ring nut 30 ÷ 40 Nm Lower ring nut 30 ÷ 40 Nm Handlebar to steering tube 45 ÷ 50 Nm
Overhaul
Carry out this operation only if strictly necessary and in any case remove and replace the old part with
a new one.
- Remove the steering tube
- Use a special tool remove the upper disk of the
fifth wheel fitting seat on the headstock by operating form the lower part of the headstock as indicated in the photograph. Afterwards remove the
lower disk of the fifth wheel operating from the upper part
Specific tooling
020004Y Punch for removing fifth wheels from
headstock
- Remove the fifth wheel fitting and the dust guard
on the steering tube as shown in figure, using the
specific tool. Proceed giving a few taps with the
mallet.
Specific tooling
020004Y Punch for removing fifth wheels from
headstock
- Refit the fifth wheel fitting and the dust guard on
the steering tube until they stop, using the specific
tool.
Specific tooling
006029Y Punch for fitting fifth wheel seat on
steering tube
SUSP - 7
Suspensions
- Use the specific tool to fit the fifth wheel fitting on
the headstock as indicated in the figure
Specific tooling
020037Y Punch
- Remove the steering tube
- Remove the attachment bracket
- Use the specific tool with the part 1 and operate
the handgrip until removing temporarily the pin and
the Nadella opposite the tool thrusting direction.
- To extract the second Nadella, use the tool with
the part 2, instead of part 1, on opposite side to the
one indicated in the figure.
Specific tooling
020021Y Front suspension service tool
- Fit the two dust guard rings "C" on the swinging
hub as shown in drawing "A".
- Connect the swinging hub to the steering tube
with the guiding pin, part 5.
- Use the specific tool fitted with part 3 on the stem
and part 4 on the tool base.
- Lubricate the pin with Z2 grease and insert it
temporarily on the swinging hub, move the tool
handgrip until part 3 is fully inserted on the steering
tube.
- Once the pin has been fitted, insert the two
spacers part 17 slightly hitting with a mallet (see
next figure).
CAUTION
USE NEW ROLLER CASINGS, PIN, SEALING
RINGS AND DUST GUARDS FOR REFITTING.
Specific tooling
020021Y Front suspension service tool
SUSP - 8
Vespa GTS 125
Vespa GTS 125
Suspensions
To fit sealing rings, roller casings and wedging
washers proceed as follows
- Lubricate the sealing rings with mineral oil and
half fill the roller casings with Z2 grease.
- Insert the seal ring on the pin and the roller bushing with wedging washers at the same time.
- Remove the specific tool and then the part 5
(guide) partially ejected in the previous assembly
stage; part 4 must be always fitted.
- Replace part 3 with part 16 on the stem.
- Push, from the handgrip, the wedging washer roller casing - seal ring unit, placing part 16 until it
stops on the swinging hub
- Repeat the operation described above using the
tool fitted with part 16 and part 22* instead of part
4 on the stem, on the side opposite the one shown
in the figure to refit the second wedging washer roller casing - sealing ring unit.
To position roller casings on the pin (pin end in
contact with the internal bottom of the roller casings) proceed as follows:
- Use the tool with part 20 and 21 fitted to the stem
as indicated in the figure.
- Push the two roller casings with the handgrip until
their bottoms make contact with the pin end.
- Use the specific tool fitted with parts 3 and 4 as
indicated for fitting the spin and push with the
handgrip until the washer is wedged in the swinging hub.
- Remove the spacers, part 17, fill with grease the
area between the steering tube and the swinging
hub, and place the dust guard rings in that place.
Carry out this operation only if strictly necessary and in any case remove and replace the old part with
a new one.
SUSP - 9
Suspensions
- Remove the steering tube
- Use a special tool remove the upper disk of the
fifth wheel fitting seat on the headstock by operating form the lower part of the headstock as indicated in the photograph. Afterwards remove the
lower disk of the fifth wheel operating from the upper part
Specific tooling
020004Y Punch for removing fifth wheels from
headstock
- Remove the fifth wheel fitting and the dust guard
on the steering tube as shown in figure, using the
specific tool. Proceed giving a few taps with the
mallet.
Specific tooling
020004Y Punch for removing fifth wheels from
headstock
- Refit the fifth wheel fitting and the dust guard on
the steering tube until they stop, using the specific
tool.
Specific tooling
006029Y Punch for fitting fifth wheel seat on
steering tube
- Use the specific tool to fit the fifth wheel fitting on
the headstock as indicated in the figure
Specific tooling
020037Y Punch
SUSP - 10
Vespa GTS 125
Vespa GTS 125
Suspensions
- Remove the steering tube
- Remove the attachment bracket
- Use the specific tool with the part 1 and operate
the handgrip until removing temporarily the pin and
the Nadella opposite the tool thrusting direction.
- To extract the second Nadella, use the tool with
the part 2, instead of part 1, on opposite side to the
one indicated in the figure.
Specific tooling
020021Y Front suspension service tool
Refitting
To refit, carry out the removal operations but in reverse order; grease the fifth wheel fittings and tighten
at the specified locking torques
Locking torques (N*m)
Handlebar to steering tube 45 ÷ 50 Nm Upper steering ring nut 30 ÷ 40 Lower steering ring nut
8 ÷ 10
Front shock absorber
Removal
- Remove the steering tube
- Remove the shock absorber lower clamps
- Remove the shock absorber upper clamps
Refitting
To refit, carry out the removal operations in reverse order, observing the prescribed tightening torques.
Locking torques (N*m)
shock absorber lower clamp 20 - 27 Nm shock absorber upper clamp 20 ÷ 30
SUSP - 11
Suspensions
Shock-absorber - calliper bracket
- Remove the front wheel hub with the brake disc
- Remove the front shock absorber lower clamps
- Remove the bracket locking Seeger ring
- Unscrew the bracket
- Before refitting the bracket in the wheel axle,
place the O-ring as shown in the photograph so
that it is correctly placed after fitting the bracket.
- Refit the washer and the Seeger ring.
- Refit the lower screws fixing the shock absorber
to the bracket and tighten at the prescribed torque
Locking torques (N*m)
Shock absorber lower clamp 20 ÷ 27
Overhaul
- The bracket for the shock absorber -calliper attachment has two roller bearings separated one
from the other as shown in the photograph
SUSP - 12
Vespa GTS 125
Vespa GTS 125
Suspensions
- Remove the two roller bearings from the bracket
with the specific tool operating on the shock absorber attachment side as shown in the photograph
Specific tooling
020376Y Adaptor handle
020441Y 26 x 28 mm adaptor
020365Y 22 mm guide
- Remove the oil seal on the wheel hub side with
the screwdriver as shown in the photograph
- Suitably hold the brake calliper - shock absorber
attachment bracket
- Fit a new oil seal and move it until it stops using
the specific tool
Specific tooling
020376Y Adaptor handle
020360Y Adaptor 52 x 55 mm
- Assemble a new roller bearing on the shock absorber side and move it until it stops using the
specific tool
Specific tooling
020036Y Punch
SUSP - 13
Suspensions
Vespa GTS 125
- Suitably hold the brake calliper - shock absorber
attachment bracket
- Assemble a new roller bearing on the wheel hub
side and move it until it stops using the specific tool
Specific tooling
020037Y Punch
Rear
Removing the rear wheel
- Remove the bracket supporting the rear shock
absorber and the muffler;
- Remove the rear wheel by unscrewing the 5
screws indicated in the photograph
Refitting the rear wheel
To refit, carry out the removal operations but in reverse order, observing the prescribed torques.
Locking torques (N*m)
Wheel fixing screws: 20 ÷ 25 Nm
Swing-arm
SUSP - 14
Vespa GTS 125
Suspensions
Removal
- Place the scooter on its centre stand;
- Remove the engine housing
- Remove the swinging arm/engine fitting shown in
the photo
- Move the engine back
- remove the spring anchoring the swinging arm to
the frame as shown in the photo
- Remove the two screws fixing the buffer support
bracket to the frame
SUSP - 15
Suspensions
- Remove the left and right caps located under the
footrest to reach the pin fixing the swinging arm to
the body.
- Remove the pin. Then remove the swinging arm.
- Check the entire swinging arm assembly.
- Check all the centring bushing components and
silent block rubber buffers.
- Replace the work components that cause excessive clearance on the rear suspension.
Overhaul
- Make sure the silent bloc is not broken. If there
is, replace it.
- Remove the seeger ring shown in the photograph
SUSP - 16
Vespa GTS 125
Vespa GTS 125
Suspensions
- Remove the full silent bloc bracket
- Undo the silent bloc ring shown in the photograph
- Hold the full silent bloc bracket in the clamp
- Using the appropriate tool, remove the silent bloc
from the bracket from the side corresponding to
the inside of the vehicle. This is to guarantee the
tool is centred properly on the support
- Install a new silent bloc, making sure it aligns
properly with the reference tooth.
- Fit the silent blocs, making sure the chamfered
part of the silent bloc matches the chamfered part
of the bracket
SUSP - 17
Suspensions
- Using the appropriate tool, fit the silent bloc as
shown in the photo
- Check there is no sticking in the movement of the
connection of the swinging arm on the engine side
to the swinging arm on the frame side.
- Check the axial clearance between the two
swinging arms using a feeler gauge
Characteristic
Standard clearance
0.40 ÷ 0.60 mm
Allowable limit after use:
1.5 mm
- To check the clearance on the frame-side arm,
mount the retainer using the pin fixing the swinging
arm to the frame and two adaptor rings of the appropriate tool 020229Y. Alternatively use two
washers with inner diameter for 12-mm pins, min.
outer diameter: 30 mm: min. thickness: 4 mm.
- Check there is no sticking in the rotation.
- Check the axial clearance of the swinging arm on
the frame side
Characteristic
Standard clearance
0.40 ÷ 0.60 mm
Allowable limit after use:
1.5 mm
SUSP - 18
Vespa GTS 125
Vespa GTS 125
Suspensions
- Separate the swinging arm on the engine side
from the vehicle side arm.
- Remove the plastic bushings and the internal
spacer shown in the photo.
- Using a suitable pin remove the roller casings as
shown in the photographs
- Using an appropriate tool plant new roller casings, being careful to position the bearings with the
O-rings facing outwards
Specific tooling
020244Y 15-mm diameter punch
020115Y Ø 18 punch
Characteristic
Length of the swinging arm tube on the engine
side:
L 175.3 + 0.3 0
Length of the internal swinging arm spacer on
the engine side:
L 183 + 0.3 0
Engine side swinging arm plastic bushing
shim:
3.5 ± 0.05 mm
Frame-side swinging arm plastic bushing
shim:
3.5 ± 0.05 mm
Length of the internal swinging arm spacer on
the frame side:
290 ± 0.1 mm
SUSP - 19
Suspensions
Vespa GTS 125
Length of the swinging arm tube on the frame
side:
283 ± 0.1 mm
- Lubricate roller casings and the plastic bushings
with grease
- Insert the spacers
- Assemble the two arms with the relative bolt in
the position shown in the photograph
- Adjust the bolt as shown in the photograph
- Position the frame side swinging arm with the
most protruding part pointing towards the silent
block side as shown in the photograph
Recommended products
AGIP GREASE PV2 Grease for the steering
bearings, pin seats and swinging arm
Soap-based lithium and zinc oxide grease containing NLGI 2; ISO-L-XBCIB2 of the swinging arm
Refitting
- To refit, perform the removal operations in reverse.
- Grease the bearings and the rolling parts with the recommended grease.
-Complete the fitting by tightening the nuts on the relative bolts to the proper tightening torque.
Locking torques (N*m)
Engine and vehicle side swinging arm junction bolt 33 ÷ 41 Nm Swinging arm pin - Engine 64 72 Body shell - Swinging arm pin 76 ÷ 83 Screw fixing the silent-block support plate to the
body 42 ÷ 52
Shock absorbers
Removal
Proceed as follows:
- place the scooter on its centre stand;
- remove the luggage rack
- lift the engine a little with a jack so as to free the
two shock absorbers;
- remove the muffler assembly;
- undo the shock absorber spring assembly clamping screw from the support fixed to the engine on
SUSP - 20
Vespa GTS 125
Suspensions
the one side and from that fixed to the muffler on
the other;
- undo the two upper nuts (one on each side) fixing
the shock absorber spring assembly to the frame
and remove the shock absorbers themselves.
Refitting
To refit, carry out the above removal operations in reverse order, observing the prescribed torques.
Locking torques (N*m)
Lower shock absorber clamping screw 33 ÷ 41 Nm Upper shock absorber fixing screws 20 ÷ 25
Nm
Exhaust bracket
Removal
Remove the full muffler assembly.
- Remove the two fixing screws of the bracket to
the engine crankcase
- Remove the split pin, the cover and the fixing nut
of the rear wheel axle and its spacer
- Remove the shock absorber lower clamp
Refitting
- The refitting procedure is in the reverse order of the removal operation being careful to respect the
torques indicated and the spacer assembly layout as shown in the photo.
SUSP - 21
Suspensions
Vespa GTS 125
Locking torques (N*m)
Bracket fixing screws to the engine crankcase: 20 ÷ 25 Nm Shock absorber lower clamp 33 ÷
41 Wheel axle clamping 104 ÷ 126 Nm
Centre-stand
REMOVAL
- Use a jack to support the vehicle properly.
- Remove the two return springs from the centre
stand.
- Undo the nut shown in the figure.
- Remove the bolt from the right side.
- Remove the centre stand.
FITTING
- On refitting tighten the nut to the specified torque.
Locking torques (N*m)
Centre stand fixing bolt 25 ÷ 30 Nm
Side stand
REMOVAL
- Uncouple the centre stand return spring;
Remove the screw shown in the photograph
FITTING
To refit, carry out the removal operations in reverse order and comply with the specified torque.
Locking torques (N*m)
Side stand fastening bolt 40 - 45 Nm
SUSP - 22
INDEX OF TOPICS
BRAKING SYSTEM
BRAK SYS
Braking system
This section è is devoted to the description of the braking system components.
Rear brake calliper
Removal
- Remove the rear wheel.
- Remove the pad retention pin.
- Using a pin partially remove the brake pad retention pin.
- Remove the screws fixing the brake calliper to
the crankcase then remove the brake calliper complete with pipe.
- Complete the extraction of the pad retention pin,
the spring and the pads.
N.B.
IF IT IS NECESSARY TO REPLACE OR SERVICE THE BRAKE CALLIPER, BEFORE REMOVING THE FITTINGS FIXING THE CALLIPER TO
THE SUPPORT BRACKET, FIRST LOOSEN
THE OIL HOSE FITTING AFTER HAVING EMPTIED THE SYSTEM OF THE CIRCUIT BEING
EXAMINED.
Overhaul
- Remove the rear brake calliper.
- Suitably hold the brake calliper in a clamp
- Remove the two calliper coupling screws as
shown in the photo
- Remove the two pistons from the calliper body
with the aid of short blasts of compressed air
through the brake fluid holes
- Remove the dust ring and the O-ring of each half
calliper.
- Remove the O-rings in the half calliper.
N.B.
WHEN REMOVING THE O-RINGS, BE CAREFUL NOT TO SCRATCH THE HALF CALLIPER
SEATS
BRAK SYS - 2
Vespa GTS 125
Vespa GTS 125
Braking system
- Check that the pistons and their seats show no
scratches.
- Wash and blow all the components carefully
- Fit the O-rings and new dust guards
- Refit the pistons in their seats being careful to
lubricate with brake fluid
- Re-couple the half callipers and lock the two
screws at the specified torque
Locking torques (N*m)
Calliper coupling screw 22 ÷ 27
Refitting
- Insert the brake pads in the calliper.
- Insert the pad fixing pin and the retention screw
being careful to position the terminals of it pointing
towards the bleed screw as shown in the photo.
- Insert the clip on the pad fixing pin
N.B.
FAILURE TO RESPECT THE PAD POSITIONING REQUIREMENTS WITH RESPECT TO THE
DIRECTION OF ROTATION COULD INHIBIT
PROPER BRAKE FUNCTION AND QUIETNESS.
BRAK SYS - 3
Braking system
- Keep the brake pads in contact with the pistons
and insert the calliper in the brake disc.
- Fix the calliper to the crankcase with the two
screws with elastic washer at the prescribed torque as shown in the photograph
- Fix the brake pipe joint to the calliper and tighten
at the prescribed torque
- Bleed the system and refit the rear wheel
Locking torques (N*m)
Brake calliper support clamping 20 ÷ 25 Nm
Brake pipe connection 20 to 25 N•m
Front brake calliper
BRAK SYS - 4
Vespa GTS 125
Vespa GTS 125
Braking system
Removal
- Remove the front wheel
- Pre-loosen the two fixing pins of the brake pads
- Remove the two front brake calliper devices fastening them to the support as shown in the photograph.
N.B.
WHEN A PROCEDURE IS PLANNED INCLUDING THE SERVICE OR REPLACEMENT OF THE
CALLIPER, FIRST LOOSEN THE FITTING CONNECTING THE PIPE TO THE BRAKE CALLIPER
Overhaul
Proceed as follows:
1) remove the two male hexagonal screws (1) and
take out the two pads (10);
2) remove the two male hexagonal screws (2) and
remove the reaction plate (3);
3) take out the fixed plate (4) from the guide;
4) remove the internal elements from the floating
body (5) with the help of short blows of compressed air through the brake fluid pipe in order to
facilitate the expulsion of pistons (6).
5) Check:
- that the plates and the body are whole and in
good condition;
- that the cylinder and the floating body of the calliper do not show signs of scratches or erosion,
otherwise replace the entire calliper;
- that the guides of the fixed plate are not scratched
or eroded, otherwise replace the entire plate;
BRAK SYS - 5
Braking system
- that the brake pad check spring works properly.
CAUTION
ALL THE INTERNAL COMPONENTS MUST BE
REPLACED EVERY TIME THE CALLIPER IS
SERVICED.
The brake pad check spring
1. pad fixing screws
2. reaction plate fixing screws
3. reaction plate
4. fixed plate
5. floating body
6. piston
7. piston sealing rings
8. guide protection rubbers
9. brake pad check spring
10. pads
Refitting
Insert the following on the front brake body:
-The sealing rings and the pistons (1).
-Refit the plate (2).
- Arrange the pad holding clamp (3).
-Refit the pads and bleed air.
-Place the calliper on the disk and lock it to the
support by tightening the bolts at the prescribed
torque.
-Lock the pipe joint to the calliper at the prescribed
torque.
-Follow the same procedure for the rear brake calliper.
Locking torques (N*m)
Screws fixing the front calliper to the support: 20 ÷ 25 Nm Screw fixing the oil connection to the calliper: 20 ÷ 25 Nm
Rear brake disc
BRAK SYS - 6
Vespa GTS 125
Vespa GTS 125
Braking system
Removal
- Remove the rear brake calliper.
- Remove the brake disc and the hub from the
wheel axle
- To remove the brake disc from the hub, hold the
unit firmly with a vice and operate on the 5 fixing
screws indicated in the photograph
Refitting
- To reassemble the brake disc on the hub, carry out the removal operations in the reverse order arranging the brake disc on the hub on the side opposite the wheel keying
- Follow the direction of rotation shown by the arrow and tighten to the prescribed torque.
- Fit the hub unit
- disc in the wheel axle
Locking torques (N*m)
Disk to the hub 11 ÷ 13 Nm
Disc Inspection
- Remove the rear brake calliper.
- Check the disc thickness with a micrometer
Characteristic
Minimum thickness allowed after use:
3.5 mm
Standard thickness:
4 +0.2-0.2 mm
- Repeat the measurement at no fewer than six points on the disc.
- Check the regular nature of the rotation of the brake disc assembly using the appropriate tool fixed
onto the brake calliper as shown in the photo.
- In order to be able to anchor the appropriate tool properly use a metal plate with M8 threaded hole
and fix it to one of the two rear brake calliper attachment points.
- Suitably fix the flange to the wheel axle with the original nut and spacer and a Æ 17 mm bearing.
N.B.
SO AS NOT TO GET A DISTORTED READING, CAUSE THE DRIVEN PULLEY SHAFT TO TURN
IN ORDER TO ROTATE THE DISC.
Specific tooling
020335Y Magnetic support for dial gauge
BRAK SYS - 7
Braking system
Characteristic
Max. deviation allowed:
0.1 mm
- If you detect incorrect values, replace the disc. If
the anomaly persists, replace the hub.
Front brake disc
Removal
- Remove the front wheel
- Remove the front brake calliper
- Remove the hub and the disc operating on the
wheel axle nut
- Hold the hub and the disc firmly and remove the
brake disc undoing the six screws indicated in the
photograph
BRAK SYS - 8
Vespa GTS 125
Vespa GTS 125
Braking system
Refitting
- Carry out the operations in the reverse order from
the removal being careful to respect the direction
of disc rotation shown by the arrow printed on it
- Tighten the six screws to the specified torque.
Locking torques (N*m)
Brake disc screws: 6 +0.5 -1 Nm
Disc Inspection
- Remove the front wheel
- Use a micrometer to check the disc thickness as
shown in the photograph
- Repeat the measurement in at least 6 points on
the disk
- Remove the front brake calliper
- In order to secure the appropriate tool adequately
use a metal plate with M8 threaded hole and fix it
to one of the two front brake calliper attachment
points
- Place the dial gauge on the disk outer edge
- Make the wheel hub turn and check the disk deviation
Specific tooling
020335Y Magnetic support for dial gauge
Characteristic
Standard thickness:
4 +0.2-0.2 mm
Max. deviation allowed:
0.1 mm
Front brake pads
BRAK SYS - 9
Braking system
Removal
- Remove the front wheel
- Pre-loosen the two fixing pins of the brake pads
- Remove the brake calliper
- Remove permanently the two pad fixing screws
- Check that there are no flaws or warping. If there
is, replace it.
- Check the thickness of the friction material is
more than 1.5 mm. If it is not , replace it
- The replacement must be made with greater residual thickness if the pad has not worn evenly. A
0.5 mm thickness difference in the residual friction
material is permitted
Refitting
To fit, proceed as follows:
- Insert the two pads in the callipers.
BRAK SYS - 10
Vespa GTS 125
Vespa GTS 125
Braking system
- Screw the two pad lock pins to the correct torque, and apply the recommended product.
- Fit the calliper on its support, tightening the two screws to the prescribed torque.
N.B.
IF IT IS NOT POSSIBLE TO CORRECTLY POSITION THE CALLIPER ON THE DISC DURING FITTING, GENTLY EXPAND THE PADS.
Recommended products
Loctite 243 Medium strength threadlock
Loctite 243 medium-strength threadlock
Locking torques (N*m)
Screw tightening calliper to the support 20 ÷ 25 Pad fastening pin 19.6 ÷ 24.5
Rear brake pads
Removal
- Remove the rear brake calliper.
- Remove the brake pad and check there are no
faults or warping. If there is, replace it.
- Check the thickness of the friction material is
more than 1.5 mm. If it is not , replace it
- The replacement must be made with greater residual thickness if the pad has not worn evenly. A
0.5 mm thickness difference in the residual friction
material is permitted
BRAK SYS - 11
Braking system
Vespa GTS 125
See also
Removal
Refitting
- Insert the brake pads
- Insert the fixing pin being careful to position the
clip with the ends towards the bleed screw as in
the photo.
- Insert the clip on the pin
- Fix the rear brake calliper to the bracket and
tighten the two screws to the specified torque.
Locking torques (N*m)
Rear brake calliper tightening screw 20 ÷ 25
Nm
Fill
Front
- Remove the rubber hood from the bleed screw.
- Insert a rubber pipe in the bleed screw to permit
the brake fluid to be recovered.
- With the left-had brake lever, load the system and
bring it up to the required pressure.
- Keeping the left-hand brake lever pulled, loosen
the bleed screw to permit the air in the system to
escape. Then do up the bleed screw
- Repeat the operation until only brake fluid comes out of the rubber pipe.
- Remove the fluid recovery pipe and refit the rubber hood over the bleed screw.
- Top up the brake fluid to the right level in the tank.
If necessary, bleeding can be done using a special vacuum pump
N.B.
DURING THE BLEEDING OPERATIONS, MAKE SURE THE BRAKE FLUID DOES NOT COME INTO
CONTACT WITH THE BODYWORK SO AS NOT TO DAMAGE IT. FURTHERMORE, DURING THE
BRAK SYS - 12
Vespa GTS 125
Braking system
BLEEDING OPERATIONS REGARDING THE BRAKE CALLIPERS, MAKE SURE THE BRAKE
FLUID DOES NOT COME INTO CONTACT WITH THE DISC BRAKES AND WITH THE BRAKE
PADS. FAILURE TO COMPLY WITH THIS NORM WILL ENDANGER THE PROPER WORKING AND
EFFICIENCY OF THE BRAKING SYSTEM
Specific tooling
020329Y MityVac vacuum-operated pump
Locking torques (N*m)
System bleed calliper fitting: 20 ÷ 25 Nm
Brake fluid level check
- Position the vehicle on a flat surface and on the
centre stand
- Remove the brake pump cover as indicated in the
photo
- Use the appropriate spyglass on the pump to
check the level of the brake fluid, as shown in the
photograph
- If the level is below the minimum, fill using the two
screws shown in the figure
- Remove the gasket and fill with DOT 4 until the
spyglass is completely covered
CAUTION
MAKE SURE THE BRAKE FLUID DOES NOT
GET INTO YOUR EYES OR ON YOUR SKIN OR
CLOTHES. IF THIS HAPPENS ACCIDENTALLY,
WASH WITH WATER.
CAUTION
THE BRAKING CIRCUIT FLUID IS HIGHLY
CORROSIVE. THEREFORE, WHEN TOPPING
IT UP, AVOID LETTING IT COME INTO CONTACT WITH THE PAINTED PARTS OF THE VEBRAK SYS - 13
Vespa GTS 125
Braking system
HICLE. THE BRAKING CIRCUIT FLUID IS HYGROSCOPIC, WHICH MEANS THAT IT
ABSORBS MOISTURE FROM THE SURROUNDING AIR. IF MOISTURE CONTAINED IN
THE BRAKE FLUID EXCEEDS A CERTAIN
VALUE, THIS WILL RESULT IN INEFFICIENT
BRAKING.
CAUTION
- BRAKING CIRCUIT FLUID IS HYGROSCOPIC.
IT ABSORBS HUMIDITY FROM THE SURROUNDING AIR. IF THE LEVEL OF HUMIDITY
IN THE BRAKE FLUID EXCEEDS A GIVEN VALUE, BRAKING EFFICIENCY WILL BE REDUCED.
Locking torques (N*m)
Float chamber screws 15 ÷ 20 Nm
Never use brake liquid in open or partially used
containers.
Under normal climatic conditions, the fluid must be
changed every 20,000 km or anyway every two
years.
For refitting purposes carry out the operations in
the reverse order from the removal operation and
respect the tightening torque of the tank cover
screws.
Front brake pump
Removal
- Remove the rear handlebar cover.
- Remove the two screws fixing the brake pump to the handlebar indicated in the photograph
- Remove the oil pipe joint from the pump
- Remove the connector to the stop light switch
BRAKE PUMP TECHNICAL DATA:
Specification
Pump right piston diameter
Pump left piston diameter
BRAK SYS - 14
Desc./Quantity
Ø 12.7
Ø 11
Vespa GTS 125
Braking system
Overhaul
Proceed as follows:
1) Remove the brake lever by loosening the retaining screw; open the cover (2) and take out the diaphragm (3);
2) remove the cap (4) and take out the internal parts in order;
3) Check that:
- The pump body shows no signs of internal damage or corrosion;
- The plunger shows no sign of damage or abnormal wear;
- The plunger return spring is in good condition.
CAUTION
ALL THE SEALS AND GASKETS MUST BE REPLACED EVERY TIME THE PUMP IS SERVICED.
BRAK SYS - 15
Braking system
Vespa GTS 125
1. Reservoir cap screw
2. Reservoir cap.
3. Diaphragm.
4. Bellows.
5. Sealing ring
6. Piston.
7. Gasket.
8. Spring.
9. Reservoir
Refitting
To refit, carry out the removal operations but in reverse order, observing the specified torques.
Locking torques (N*m)
Oil pipe joint to the pump: 20 - 25 Brake pump fixing screws to the handle bar: 7 ÷ 10 Nm
BRAK SYS - 16
INDEX OF TOPICS
COOLING SYSTEM
COOL SYS
Cooling system
Vespa GTS 125
Water pump - overhaul
Water pump assembly
With a hot air gun heat the inner side of the flywheel cover.
AVOID OVERHEATING AS THIS MAY ALTER
THE PAINTED SURFACE.
Specific tooling
020151Y Air heater
- Place the flywheel cover on the ring base following the same procedure as for removal.
- Place the two bearings on the specific punch.
N.B.
USE A NEW BEARING WHEN REFITTING
- Use grease to keep the bearings on the appropriate tool.
- Use a plastic mallet to insert the bearings on the housing up to the stop.
- Assembly the ceramic ring and the corresponding rubber gasket. The ceramic ring chamfering
should always face towards the gasket.
- Lubricate the rubber gasket and insert the unit on
the flywheel cover.
Use the punch of the appropriate tool manually if
necessary.
ALWAYS USE NEW CERAMIC RING AND GASKETS. ASSEMBLING THE CERAMIC SEALING
RING IN A MANNER OTHER THAN MANUALLY
MAY DAMAGE THE RING.
Specific tooling
020440Y Water pump service tool
- Insert the drive on the guide pin of the support
base which is part of the appropriate tool. Check
that the convex part faces upwards.
COOL SYS - 2
Vespa GTS 125
Cooling system
- Insert the flywheel cover with bearings on the appropriate tool.
- Insert the shaft together with the mechanical gaskets on the bearings.
- With the appropriate punch and socket, insert the
shaft in the bearings and the drive until the end of
stroke of the appropriate tool cannot be seen.
N.B.
CENTRE THE PUNCH CORRECTLY ON THE
ROTOR. PUSH THE SHAFT IN AND CHECK
THAT THE FLYWHEEL COVER ROTATES
SMOOTHLY. FAILURE TO RESPECT THIS
PROCEDURE DAMAGES THE DRIVE.
- Reassemble the rotor cover with a new O-Ring.
-Tighten the 3 fixing screws to the torque below:
N.B.
DO NOT LUBRICATE THE O-RING. FAILURE
TO RESPECT THIS RULE RESULTS IN RING
DISTORTION.
Locking torques (N*m)
Water pump cover screws 3 ÷ 4
Removal
- Check the water pump if noise in the bearings or liquid leaking from the drainage hole inside the cover
is detected.
-Remove the flywheel cover together with the water pump from the engine.
- Remove the rotor cover by unscrewing the 3 retainers indicated in the figure.
-Place the flywheel cover on the ring base which is part of the tool
N.B.
COOL SYS - 3
Cooling system
Vespa GTS 125
TO AVOID DAMAGING THE COVER SURFACE THAT SEALS THE COOLANT, USE THE RING
BASE WITH THE ACCURATELY MACHINED SURFACE FACING THE FLYWHEEL COVER.
Specific tooling
020440Y Water pump service tool
-With an appropriate socket and punch, forming part of the specific tool 020440y, extract the shaft
together with the rotor from the drive and the bearings.
- Use a screwdriver to remove the static part of the ceramic seal from the flywheel cover.
COOL SYS - 4
Vespa GTS 125
Cooling system
- Place the flywheel cover below the socket making
sure it is perfectly levelled.
- Use the punch in the inverted position to extract
the two ball bearings.
Water pump ceramic seal
Our Leader, Quasar, and Master liquid cooled engines are equipped with water pumps fitted with the
ceramic seal in the subject. This component is intended to guarantee the leak tightness of the coolant
in relation to the pump shaft. The seal achieved via two special ceramics, a static one and a spinning
one, kept in contact by the thrust of a spring, coaxially mounted onto the pump shaft. The efficiency of
this system is guaranteed by the accurate machining and cleaning of the components as they are fitted;
in any case, ceramic seals are subjected to a running in period. During this period (1,000 ± 1,500 km),
there may be small leaks through draining holes, which remain visible on the aluminium crankcase.
This phenomenon is particularly visible there where the hole is more exposed (Quasar and Master). In
such cases we recommend cleaning the casing in order to be able to check again for leaks after a
distance of more than 1500 km. If leaks continue or in the event of real losses, the ceramic seal should
be replaced. For these operations, observe the tools and instructions given in the relevant service
station manuals.
Note: The ceramic seal may be overhauled according to the following couplings:
•
Coupling "A": seal ring no. 485084 with ceramic seal no. 486216
•
Coupling "B": seal ring no. 841329 with ceramic seal no. 841330
The couplings above may be selected according to their availability, as they are interchangeable.
Component check
- Check that the rotor does not show abnormal wear or dents;
- Check that the rotor shaft is not rusty;
- Check that there is no rust on the bearing seats or the ceramic seal;
- Check that the drive does not show dents and that it is perfectly integral with the steel hub.
COOL SYS - 5
Cooling system
Check
1) Look to see that the thermostat is not damaged.
2) Fill a metal container with approx. 1 litre of water.
Immerse the thermostat, and keep it in the centre
of the container.
Immerse the multimeter temperature probe, and
keep it close to the thermostat.
Heat up the container using the thermal gun.
Check the temperature when the thermostat starts
to open:
Heat up until the thermostat is completely open.
3) Replace the thermostat if it is not working properly.
CAUTION
TO EXECUTE THE TEST CORRECTLY, MAKE
SURE NEITHER THE THERMOSTAT NOR THE
THERMOMETER TOUCHES THE CONTAINER.
Specific tooling
020331Y Digital multimeter
020151Y Air heater
Characteristic
Thermostat check: Opening start temperature
69.5 ÷ 72.5°C
COOL SYS - 6
Vespa GTS 125
INDEX OF TOPICS
CHASSIS
CHAS
Chassis
Vespa GTS 125
This section è is devoted to the operations that can be carried out on the vehicle's bodywork.
Seat
- Remove the helmet compartment
- Remove the two screws shown in the photograph
- Remove the saddle
- Remove the helmet compartment
- Remove the 2 nuts indicated in the photograph
- Free the electric cables form the retaining clamps
indicated in the photograph
- Remove the saddle opening transmission cable
- Remove the saddle manual opening transmission cable.
CHAS - 2
Vespa GTS 125
Chassis
- Remove the electric connector from the saddle
opening actuator
- Remove the two screws shown in the photograph
- Remove the clip from the transmission
- Remove the actuator from the supporting bracket
Rear rack
- Remove the helmet compartment
- Remove the 4 screws indicated in the figure
- Remove the two screws, indicated in the figure,
that fix the luggage rack to the body
CHAS - 3
Chassis
Rear handlebar cover
- Remove the front handlebar cover
- Undo the 4 screws indicated in the photograph
-Disconnect the odometer cable
-After disconnecting the wiring remove the rear
handlebar.
Instrument panel
- Remove the rear handlebar cover;
- Remove the four screws indicated in the figure
- Remove the instrument panel.
Front handlebar cover
- Remove the front grille
- Remove the front screw indicated in the figure
CHAS - 4
Vespa GTS 125
Vespa GTS 125
Chassis
-Undo the 2 screws indicated in the figure;
- Remove the front handlebar cover
- Disconnect the front headlamp connectors
Headlight assy.
- Operate the screw indicated in the figure to remove the front turn indicator
Knee-guard
- Remove the rear handlebar cover.
- Remove the two screws indicated in the photograph and located on the shield under the grille
CHAS - 5
Chassis
- Remove the expansion tank cover and then its
cap
- Remove the central screw inside the glove-box,
indicated in the photograph
- Remove the two screws indicated in the photograph and located below the expansion tank cover
and the left cover respectively
- Remove the shield back plate lower screws, to
the right and left side of the shield back plate, as
indicated in the photograph
CHAS - 6
Vespa GTS 125
Vespa GTS 125
Chassis
- Remove the electric saddle opening switch, the
fuse box and the manual saddle opening cable as
shown in the photograph
Removing the ignition key-switch when on *off*
- Remove the shield back plate.
- Remove the immobilizer aerial as shown in the
figure.
- Detach the electrical wiring.
- Remove the ignition key-switch, by removing the
spring retainer shown in the figure.
CHAS - 7
Chassis
- Lightly push the master-cylinder and extract the
lock from the notch shown in the figure.
- Hence extract the master-cylinder complete with
the key-switch.
- For the reassembly proceed in the reverse order.
Removing the ignition key-switch when on *lock*
In position "Lock", it is not possible to access the
cylinder retaining spring. The spring must then be
removed as shown in the figure, allowing the lock
spring to be pressed out.
N.B.
FOR REASSEMBLY FROM THIS POSITION,
RELEASE THE STEERING WHEEL AND SET
THE LOCK BODY (INSIDE AND OUTSIDE
PART) TO "OFF". THEN, PROCEED AS DESCRIBED IN PARAGRAPH REMOVAL, LOCK
IN OFF POSITION.
CHAS - 8
Vespa GTS 125
Vespa GTS 125
Chassis
Front wheel housing
•
Remove the front fork;
•
Unscrew the central stud of the wheel
well at the frame;
•
Disconnect the brake pipe to the pump
and pull it out;;
•
Remove the odometer transmission..
Taillight assy.
- Operate the screw indicated in the figure to remove the rear turn indicator
Remove screw «A» to remove the rear headlight
assembly.
Access to taillight bulbs, stop light bulb and license
plate bulb.
To reassemble, repeat the operation in the reverse
order.
N.B.
IF MISTING IS NOTICED ON THE INSIDE OF
THE HEADLAMP GLASS, THIS DOES NOT INDICATE A FAULT AND IS RELATED TO THE
HUMIDITY AND/OR TO LOW TEMPERATURES.
THE PHENOMENON SHOULD QUICKLY DISAPPEAR WHEN THE LIGHT IS SWITCHED ON.
THE PRESENCE OF DROPS OF WATER, ON
THE OTHER HAND, COULD INDICATE THAT
CHAS - 9
Chassis
WATER IS INFILTRATING. CONTACT THE
PIAGGIO AFTER-SALES SERVICE NETWORK.
Footrest
- Remove the shield back plate
- Remove the battery compartment cover
- Remove the side fairings
- Remove the central screw located under the battery compartment cover as indicated in the figure
- Remove the passenger footrests undoing the two
screws indicated in the figure
- Remove the right and left screws fixing the footrest indicated in the figure
- Remove the right and left lower covers as shown
in the figure
CHAS - 10
Vespa GTS 125
Vespa GTS 125
Chassis
- Remove the screws under the non-slip rubber
mat of the footrest as indicated in the photograph
Side fairings
- Remove side fairings, right and left, by undoing
the 2 screws shown in the figure
Rear mudguard
- Remove the air filter
- Remove the screw indicated in the photograph
- Remove the mudguard
Helmet bay
- Lift the saddle and remove the helmet compartment
CHAS - 11
Chassis
Vespa GTS 125
Fuel tank
- Remove the helmet compartment
- Remove the side fairings
- Remove the muffler
- Remove the luggage rack
- Remove the shock absorber upper clamps
- Remove the two screws, indicated in the figure,
that fix the tank to the body
- Remove the screw indicated in the figure that fixes the tank to the body after removing the rear headlight assembly
- Remove the two turn indicators
- Use a jack to lift the body so that there is enough
space between the vehicle rear side and the engine to slide off the tank
To refit, perform the steps in the reverse direction
to disassembly
CHAS - 12
Vespa GTS 125
Chassis
Rear central cover
- Remove the four screws indicated in the figure
Front mudguard
- First remove the steering tube and uncouple the
front brake pipes from the calliper in order to remove the front mudguard
- Remove the three mudguard-steering tube
clamps indicated in the figure
Radiator fan
- In order to carry out any operation on the radiator
unit, flow out the coolant in the coolant delivery
pipe in the pump, indicated in the photograph.
CHAS - 13
Chassis
Vespa GTS 125
- Remove the shield back plate;
- Remove the coolant feed and return hoses from
the right radiator;
- Unscrew the 4 screws fixing the radiator to the
body;
- Detach the radiator
- Detach the pipe from the plastic duct by removing
the plastic clip shown in the photograph. Then remove the duct.
- The same procedure also applies to the left radiator for which it is necessary to remove the electrical fan first by undoing the 3 screws indicated in
the photograph.
To refit, perform the removal operations but in reverse order being careful when positioning the news
clips for the fluid hoses and when filling the cooling system.
Front central cover
- Remove the "PIAGGIO" clip-on badge
- Unscrew the screw indicated in the figure
- Remove the grille
CHAS - 14
INDEX OF TOPICS
PRE-DELIVERY
PRE DE
Vespa GTS 125
Pre-delivery
Carry out the listed tests before delivering the vehicle.
Warning- be very careful when handling fuel.
Aesthetic inspection
Appearance checks:
- Paintwork
- Fitting of plastics
- Scratches
- Dirt
Tightening torques inspection
• Safety Locks • Cover retaining screws
SAFETY LOCKS
Name
Shock absorber upper fixing: rear
Shock absorber bottom fixing: rear
Left shock absorber lower support bolts
Front wheel axle nut
Rear wheel axle nut
Rear brake disc bolts
swinging arm bolt - chassis
Engine swinging arm bolt
Handlebar clamping bolts
Upper steering ring nut
Lower steering ring nut
Torque in Nm
20 to 25 N•m
33 to 41 N•m
20 ÷ 25
75 ÷ 90
104 ÷ 126
11 ÷ 13
76 ÷ 83 Nm
64 ÷ 72 Nm
45 ÷ 50 Nm
30 ÷ 40
8 ÷ 10
Electrical system
• Main switch
• Lights: high beams, low beams, side/taillights (front and rear) and relevant warning lights
- Regulating the headlights according to the regulations currently in force
• Front and rear stop light buttons and relative light •Turn indicators and relative telltales
• Instrument lighting
• instruments: fuel and temperature indicator
•Instrument panel lights
• Horn
• Electrical start up
• Engine stop by emergency stop switch and side stand
• Electrical saddle opening button
CAUTION
TO ENSURE MAXIMUM PERFORMANCE, THE BATTERY MUST BE CHARGED BEFORE USE.
INADEQUATE CHARGING OF THE BATTERY WITH A LOW LEVEL OF ELECTROLYTE BEFORE
IT IS FIRST USED SHORTENS THE LIFE OF THE BATTERY.
PRE DE - 2
Vespa GTS 125
Pre-delivery
CAUTION
WHEN INSTALLING THE BATTERY, ATTACH THE POSITIVE LEAD FIRST AND THEN THE NEGATIVE LEAD.
WARNING
BATTERY ELECTROLYTE IS TOXIC AND IT MAY CAUSE SERIOUS BURNS. IT CONTAINS SULPHURIC ACID. AVOID CONTACT WITH EYES, SKIN AND CLOTHING.
IN CASE OF CONTACT WITH EYES OR SKIN, RINSE WITH ABUNDANT WATER FOR ABOUT 15
MINUTES AND SEEK MEDICAL ATTENTION AT ONCE.
IF IT IS SWALLOWED, IMMEDIATELY DRINK LARGE QUANTITIES OF WATER OR VEGETABLE
OIL. SEEK IMMEDIATE MEDICAL ATTENTION.
THE BATTERIES PRODUCE EXPLOSIVE GAS; KEEP THEM AWAY FROM NAKED FLAMES,
SPARKS AND CIGARETTES. IF THE BATTERY IS CHARGED IN A CLOSED PLACE, TAKE CARE
TO ENSURE ADEQUATE VENTILATION. ALWAYS PROTECT YOUR EYES WHEN WORKING
CLOSE TO BATTERIES.
KEEP OUT OF THE REACH OF CHILDREN
CAUTION
NEVER USE FUSES WITH A CAPACITY HIGHER THAN THE RECOMMENDED CAPACITY. USING
A FUSE OF UNSUITABLE RATING MAY SERIOUSLY DAMAGE THE VEHICLE OR EVEN CAUSE
A FIRE.
Levels check
Level check:
- Hydraulic brake system liquid level.
- Rear hub oil level
- Engine coolant level
- Engine oil level
Road test
Test ride
- Cold start
- Instrument operations
- Response to the throttle control
- Stability on acceleration and braking
- Rear and front brake efficiency
- Rear and front suspension efficiency
- Abnormal noise
Static test
Static control after the test ride:
• Hot engine restart
• Starter operation
• Minimum seal (turning the handlebar)
• Uniform steering rotation
• Possible losses
PRE DE - 3
Pre-delivery
Vespa GTS 125
• Electrical radiator fan operation
CAUTION
CHECK AND ADJUST TYRE PRESSURE WITH TYRES AT AMBIENT TEMPERATURE.
CAUTION
NEVER EXCEED THE RECOMMENDED INFLATION PRESSURES OR TYRES MAY BURST.
Functional inspection
Functional check up:
• Hydraulic braking system: lever travel
• Clutch: proper functioning check
• Engine: proper general functioning and no abnormal noise check
• Other: papers check, frame and engine number check, tools and equipment, licence plate fitting, lock
check, tyre pressure check, rear-view mirror and any accessory fitting
PRE DE - 4
INDEX OF TOPICS
TIME
TIME
Vespa GTS 125
Time
This section is devoted to the time necessary to carry out repairs.
For each operation, the description, code and time envisages are specified.
Engine
ENGINE
1
Code
001001
2
3
003064
003057
Action
Engine from frame - Removal
and refit.
Engine oil - change
Engine retainer - Tighten nuts
Duration
Crankcase
CRANKCASE
1
Code
001153
2
001133
TIME - 2
Action
Crankcase halves gasket Replacement
Engine crankcase- Replacement
Duration
Vespa GTS 125
Time
Crankshaft
CRANKSHAFT
1
Code
001099
2
001117
Action
Oil seal, flywheel side - Replacement
Crankshaft - Replacement
Duration
Cylinder assy.
TIME - 3
Vespa GTS 125
Time
CYLINDER- PISTON
1
Code
001002
2
001154
Action
Cylinder-Piston - Replacement
Pin ring piston unit - Service
Duration
Cylinder head assy.
VALVE HEAD
1
2
3
4
5
6
TIME - 4
Code
001126
001045
001049
001056
001083
001057
Action
Head - Replacement
Valves - Replacement
Valves - Adjustment
Head gasket - Replacement
Thermistor - Replacement
Thermostat - Replacement
Duration
Vespa GTS 125
Time
Rocker arms support assy.
CAM SHAFT
1
Code
001148
2
001044
Action
Rocking lever valve - Replacement
Camshaft - Replacement
Duration
Cylinder head cover
TIME - 5
Vespa GTS 125
Time
HEAD COVER
1
2
3
Code
001093
001089
001088
4
001074
Action
Spark plug - Replacement
Head cover - Replacement
Head cover gasket - Replacement
Oil vapour recovery pipe - Replacement
Duration
Chain tensioner
CHAIN TIGHTENER
1
Code
001129
2
001124
TIME - 6
Action
Chain tightener - Overhaul
and replacement
Lubrication by-pass - Replacement
Duration
Vespa GTS 125
Time
Oil filter
OIL FILTER
1
2
Code
001123
001160
Action
Oil filter -Replacement
Oil pressure sensor - Replacement
Duration
Driven pulley
DRIVEN PULLEY
1
2
3
Code
001022
001012
001110
Action
Clutch - Replacement
Driven pulley - Service
Driven pulley - Replacement
Duration
TIME - 7
Vespa GTS 125
Time
4
Code
001155
Action
Clutch bell - Replacement
Duration
Oil pump
OIL SUMP PUMP
1
Code
001125
2
3
4
5
001051
001042
001112
001122
6
7
001130
001172
TIME - 8
Action
Chain guide pads - Replacement
Belt/Timing chain - Change
Oil pump - Service
Oil pump - change
Oil pump chain - Replacement
Oil sump - Replacement
Chain cover flap - change
Duration
Vespa GTS 125
Time
Final gear assy.
FINAL REDUCTION
1
Code
001010
2
3
003065
001156
4
004125
Action
Reduction gear - Replacement
Gear box oil - Replacement
Geared reduction unit cover Replacement
Rear wheel axle - Replacement
Duration
TIME - 9
Vespa GTS 125
Time
Driving pulley
DRIVING PULLEY
1
Code
001086
2
3
001011
001066
4
001006
TIME - 10
Action
Driving half-pulley - Replacement
Driving belt - Replacement
Driving pulley - Removal and
Refitting
driving pulley - Service
Duration
Vespa GTS 125
Time
Transmission cover
TRANSMISSION COVER
1
Code
001135
2
001096
3
001131
Action
Transmission cover bearing Replacement
Transmission crankcase cover - Replacement
Transmission air intake - Replacement
Duration
TIME - 11
Vespa GTS 125
Time
Starter motor
ELECTRICAL START UP
1
2
Code
001020
001017
3
001141
TIME - 12
Action
Starter motor - Replacement
Start-up pinion - Replacement
Belt anti-flapping roller - Replacement
Duration
Vespa GTS 125
Time
Flywheel magneto
MAGNETO FLYWHEEL
1
2
Code
001087
001113
3
001067
4
001058
5
001161
6
001162
7
001173
Action
Flywheel cover - replace
Water pump / Pump rotor Replacement
Stator - Removal and Refitting
Complete flywheel - Replacement
Secondary air filter - Replacement
Secondary air filter box - Replacement
Rotor - Replacement
Duration
TIME - 13
Vespa GTS 125
Time
Carburettor
CARBURETTOR
1
2
Code
001013
007020
3
4
5
001008
001063
001081
6
7
003058
001136
TIME - 14
Action
Intake manifold - change
Carburettor heating tubing replacement
Carburettor - Inspection
Carburettor - Replacement
Automatic choke - Replacement
Carburettor - Adjustment
Exhaust emissions - Adjustment
Duration
Vespa GTS 125
Time
Exhaust pipe
MUFFLER
1
2
Code
001009
001095
Action
Muffler - Replacement
Muffler guard - Replacement
Duration
TIME - 15
Vespa GTS 125
Time
Air cleaner
AIR CLEANER
1
2
Code
001015
001014
3
004122
TIME - 16
Action
Air filter box - Replacement
Air filter - Replacement /
cleaning
Air cleaner/ carburettor fitting
- Replacement
Duration
Vespa GTS 125
Time
Frame
FRAME
1
2
3
Code
004001
004085
004149
4
5
004053
004015
6
7
004023
004159
Action
Chassis - Replacement
Fairing (1) - Replacement
Shield central cover - Replacement
Spoiler - Replacement
Footrest - Removal and Refitting
Shield rim - Replacement
Plates / Stickers - Replacement
Duration
TIME - 17
Vespa GTS 125
Time
Centre-stand
STAND
1
2
Footrests
TIME - 18
Code
004102
004004
Action
Side stand - Replacement
Stand - Replacement
Duration
Vespa GTS 125
Time
MATS AND COVERS
1
2
3
Code
005007
004079
004071
4
5
005046
004078
Action
Battery - Replacement
Footrest - replacement
Battery compartment - replacement
Battery cover - change
Front/rear footrest rubber Replacement
Duration
Rear cover
REAR SHIELD
1
2
Code
004083
004081
Action
Glove box - Replacement
Glove box door - Replacement
Duration
TIME - 19
Vespa GTS 125
Time
Underseat compartment
HELMET COMPARTMENT
1
Code
004136
2
004016
3
005048
TIME - 20
Action
License plate support - Replacement
Helmet compartment - Removal and Refitting
Licence plate holder - Replacement
Duration
Vespa GTS 125
Time
Mudguard
MUDGUARDS
1
Code
004002
2
004009
3
003044
Action
Front mudguard - Replacement
Rear mudguard - Replacement
Shock absorber cover - Replacement
Duration
TIME - 21
Vespa GTS 125
Time
Fuel tank
FUEL TANK
1
2
3
Code
004005
005010
004109
4
004007
TIME - 22
Action
Fuel tank - Replacement
Tank float - Replacement
Fuel tank breather - Replacement
Fuel valve - Replacement
Duration
Vespa GTS 125
Time
Expansion tank
EXPANSION TANK
1
2
Code
007002
007016
3
007001
4
007014
5
007013
6
007003
7
001052
Action
Water cooler - Replacement
Fan complete with support Replacement
Expansion tank - Replacement
Radiator thermal switch - Replacement
Expansion tank / radiator
connecting hose - Replacement
Delivery line and coolant return - Replacement
Coolant and air bleed - Replacement
Duration
TIME - 23
Vespa GTS 125
Time
Rear shock-absorber
REAR SHOCK ABSORBER
1
Code
003007
Action
Rear shock
absorber Removal and
Refitting
Steering column bearings
TIME - 24
Duration
Vespa GTS 125
Time
STEERING FIFTH WHEELS
1
Code
003002
2
003073
Action
Steering fifth wheel - Replacement
Steering clearance - Adjust
Duration
Handlebar covers
HANDLEBAR COVERS
1
Code
004018
2
004019
Action
Front handlebar covers - Replacement
Rear handlebar covers - Replacement
Duration
TIME - 25
Vespa GTS 125
Time
Handlebar components
HANDLEBAR COMPONENTS
1
Code
003001
2
002067
3
002024
4
5
6
7
005017
002059
002071
003059
8
9
002060
002063
10
003061
11
002037
TIME - 26
Action
Handlebar - Removal and refitting
Rear brake pump - Replacement
Front brake pump - Removal
and refitting
Stop switch - Replacement
Right-hand knob - change
Left hand grip - Replacement
Counterweight - Replacement
Throttle grip - Replacement
Throttle control transmission
- Replacement
Accelerator transmission adjust
Brake or clutch lever - Replacement
Duration
Vespa GTS 125
Time
Swing-arm
SWINGING ARM
1
Code
001072
2
004058
Action
Swinging arm - Engine-chassis connection - Replacement
Silent block - Replacement
Duration
TIME - 27
Vespa GTS 125
Time
Brake hoses
CALLIPER BRAKE PIPING
1
Code
003071
2
003070
3
4
002040
002048
5
6
002068
002021
7
002020
8
002007
9
002002
10
002047
11
002080
TIME - 28
Action
Rear brake pads/shoes Check wear
Front brake pads / Shoes Check wear
Front brake calliper - Check
Rear brake calliper - Replacement
Rear brake calliper - Check
Front brake piping - Replacement
Rear brake pipes - Removal
and refitting
Front brake pads/shoes - removal and installation
Rear brake pad/s shoes - removal and refitting
Front brake fluid and air
bleeding system - Replacement
Rear brake oil bleeding system - Replacement
Duration
Vespa GTS 125
Time
Seat
SADDLE
1
Code
004136
2
004016
3
005048
Action
License plate support - Replacement
Helmet compartment - Removal and Refitting
Licence plate holder - Replacement
Duration
TIME - 29
Vespa GTS 125
Time
Instrument panel
INSTRUMENT PANEL
1
2
3
4
Code
004066
005014
005041
005077
5
005006
6
7
005040
005121
8
9
005039
005078
10
005038
11
005076
TIME - 30
Action
Driving mirror - Replacement
Odometer - Replacement
Starter button - Replacement
Emergency stop switch - Replacement
Light switch or turn indicators
- Replacement
Horn button - Replacement
Saddle opening button - Replacement
Headlight switch - replace
Odometer glass - Replacement
Instrument panel warning
light bulbs - Replacement
Clock / battery - Replacement
Duration
Vespa GTS 125
Time
Locks
LOCKS
1
Code
002083
2
002092
3
004158
4
005072
5
005099
6
004054
7
8
004010
005016
Action
Saddle opening transmission
- Replacement
Transmission splitter/ hook
transmission - Replacement
Saddle opening splitter - Replacement
Immobilizer aerial - Replacement
Electric saddle opening device - Replacement
Saddle lock catch - Replacement
Anti-theft lock - Replacement
Key switch - Replacement
Duration
TIME - 31
Vespa GTS 125
Time
Turn signal lights
TURN INDICATOR LIGHTS
1
2
3
Code
005002
005005
005032
4
005067
5
005008
6
005066
7
005031
8
9
005090
005068
10
005022
11
005012
12
005091
TIME - 32
Action
Front headlamp - change
Taillight - Replacement
Transparent licence plate
cover - replace
Front turn indicator bulb - Replacement
Front headlamp bulbs - Replacement
Rear light bulbs - Replacement
Licence plate light bulb - Replacement
Stop light bulb - Replacement
Rear turn indicator bulb - Replacement
Rear turn indicators - Replacement
Front turn indicator - Replacement
Turn indicator glass - Replacement
Duration
Vespa GTS 125
Time
Front wheel
FRONT WHEEL
1
2
Code
002041
003033
3
4
004123
003037
5
6
003047
003063
Action
Brake disc - Replacement
Front wheel hub- Replacement
Front wheel - Replacement
Front wheel rim- Replacement
Front tyre - Replacement
Tyre pressure - Check
Duration
Grease tone wheel or drive
Please take note that the code has been introduced:
900001 - Tone wheel / drive greasing - 15'.
Never mistake the codes 002011 (movement sensor replacement) and 005089 (tone wheel replacement) in the event of noise of the indicated
components. The grease recommended is TUTELA MRM 2 (soap-based lithium grease with Molybdenum disulphide).
In the following points we indicate with an arrow
the area to be greased (1 - Drive, 2 - Tone wheel)
TIME - 33
Vespa GTS 125
Time
Rear wheel
REAR WHEEL
1
2
Code
001016
004126
3
001071
4
002070
5
003077
6
002028
7
003063
TIME - 34
Action
Rear wheel - Replacement
Rear wheel tyre - Replacement
Front wheel rim - Removal
and refitting
Rear brake disc - Replacement
muffler/rear shock absorber
support arm - Service
Rear wheel hub - Replacement
Tyre pressure - Check
Duration
Vespa GTS 125
Time
Fuel pump
FUEL PUMP
1
2
Code
004073
004089
3
4
004072
004086
5
004086
Action
Fuel pump - Replacement
Tank / petrol pump pipe - Replacement
Fuel filter - Replacement
Petrol pump depression tube
- Replacement
Petrol pump depression tube
- Replacement
Duration
TIME - 35
Vespa GTS 125
Time
Electric devices
ELECTRIC DEVICES
1
Code
001094
2
3
4
001069
005003
002049
5
6
7
001023
005009
005001
8
9
005114
005035
10
005011
11
12
005054
005019
13
002051
14
15
005024
002025
TIME - 36
Action
Spark plug cap - Replacement
HV coil - replace
Horn - Replacement
Odometer cable - Replacement
Control unit - Replacement
Voltage regulator - replace
Electrical system - Removal
and refitting
Electrical system - Service
Headlight remote control Replacement
Start-up remote control
switch - Replacement
Fuse holder - Replacement
Fuse terminal block - Replacement
Odometer transmission assembly - Replacement
Battery fuse - Replacement
Brake piping - Replacement
Duration
Vespa GTS 125
Time
Front suspension
FRONT SUSPENSION
1
Code
003011
2
3
4
003045
003010
003035
5
003034
6
001064
Action
Front shock absorber - Removal and Refitting
Steering tube - Replacement
Front suspension - Service
Shock absorber support and
brake calliper - Replacement
Front wheel hub bearing - Replacement
Odometer reel - Replacement
Duration
TIME - 37
Was this manual useful for you? yes no
Thank you for your participation!

* Your assessment is very important for improving the work of artificial intelligence, which forms the content of this project

Download PDF

advertisement