VESPA S 50 4T 4V (2008) Specifications

MANUALE STAZIONE DI SERVIZIO
********
Vespa S 50 4T 4V (2008)
MANUALE
STAZIONE DI
SERVIZIO
Vespa S 50 4T 4V (2008)
The descriptions and illustrations given in this publication are not binding. While the basic specifications
as described and illustrated in this booklet 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/models shown in this publication are available in all countries. The availability of single
models should be checked at the official Piaggio sales network.
"© Copyright 2008 - 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)
MANUALE STAZIONE DI
SERVIZIO
Vespa S 50 4T 4V (2008)
Questo manuale per stazioni di servizio è stato realizzato da Piaggio & C. Spa per essere utilizzato dalle
officine dei concessionari e sub-agenzie Piaggio-Gilera. Si presuppone che chi utilizza questa
pubblicazione per la manutenzione e la riparazione dei veicoli Piaggio, abbia una conoscenza base dei
principi della meccanica e dei procedimenti inerenti la tecnica della riparazione dei veicoli. Le variazioni
importanti nelle caratteristiche dei veicoli o nelle specifiche operazioni di riparazione verranno
comunicate attraverso aggiornamenti di questo manuale. Non si può comunque realizzare un lavoro
completamente soddisfacente se non si dispone degli impianti e delle attrezzature necessarie, ed è per
questo che vi invitiamo a consultare le pagine di questo manuale riguardanti l'attrezzatura specifica e il
catalogo degli attrezzi specifici.
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
CHASSIS
PRE-DELIVERY
TIME
BRAK SYS
CHAS
PRE DE
TIME
INDEX OF TOPICS
CHARACTERISTICS
CHAR
Vespa S 50 4T 4V (2008)
Characteristics
Rules
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 naked 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 spare parts 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 solvents. Lubricate all
the work surfaces, except tapered couplings, before refitting these parts.
- 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 - 7
Vespa S 50 4T 4V (2008)
Characteristics
Vehicle identification
VEHICLE IDENTIFICATION
Specification
Chassis prefix
Engine prefix
Desc./Quantity
ZAPC383000001001
C383M
Dimensions and mass
WEIGHTS AND DIMENSIONS
Specification
Width
Length
Wheelbase
Maximum height
Kerb weight
Desc./Quantity
740 mm
1755 mm
1290 mm
1140 mm
110 ± 5 kg
Engine
ENGINE
Specification
Type
CHAR - 8
Desc./Quantity
single-cylinder, four-stroke and four-valve, air-cooled engine
Vespa S 50 4T 4V (2008)
Characteristics
Specification
Bore
Stroke
Cubic capacity
Max. Power
MAX. torque
Compression ratio
Timing system
Desc./Quantity
39 mm
41.8 mm
49.93 cm³
3.2 kW at 8250 rpm
3.8 Nm at 7750 rpm
11.5 ÷ 12 : 1
single overhead camshaft, chain-driven, on the left-hand side,
three-arm rocking levers set up with threaded set screw
1900 ÷ 2000 rpm
Sponge, soaked in a mixture (50% SELENIA Air Filter Oil and
50% unleaded petrol).
electric starter/kick-starter
engine lubrication with lobe pump (in the crankcase) driven by
a chain. Mesh pre-filter and centrifugal on the crankshaft
Gravity feed, with unleaded petrol (with a minimum octane rating of 95) with carburettor.
intake 0.10 mm
discharge 0.15 mm
depression type, KEIHIN NCV ø 20
forced air circulation
Engine idle speed
Air filter
Starting system
Lubrication
Fuel supply
Valve clearance (cold engine)
Carburettor
Cooling
OIL PUMP
Specification
Type
Distance between the rotors
Axial rotor clearance
Distance between the outer rotor and the pump body
Levelness
Desc./Quantity
Trochoidal
Admissible limit clearance: 0.15 mm
Limit values admitted: 0.09 mm
Admissible limit clearance: 0.20 mm
0.1 mm
OIL FILTER
Specification
Type
Desc./Quantity
mesh, plastic and centrifugal filter, before the oil pump and coaxially mounted onto the crankshaft keyed on the right crank
Transmission
TRANSMISSION
Specification
Transmission
Desc./Quantity
With automatic expandable pulley variator, torque server, Vbelt, automatic clutch, gear reduction unit.
Capacities
CAPACITY
Specification
Fuel tank (including a ~ 2 l reserve)
Rear hub
Engine oil
Desc./Quantity
approx. 8.5 l
85 cm³
~ 850 cc
Electrical system
When the advance check is carried out with a stroboscopic gun, add 10° flywheel keying to the table
below.
CHAR - 9
Vespa S 50 4T 4V (2008)
Characteristics
ELECTRICAL COMPONENTS
1
2
3
4
5
Specification
Ignition advance
Spark plug
Battery
Fuses
Generator
CHECKING REMOTE CONTROLS «A» OPERATING AS CIRCUIT BREAKERS
1) Check that, given regular conditions, there is no
continuity between terminals 30 and 87.
2) Apply 12V voltage to power terminals 85 and 86
of the remote control.
3) With the remote control powered, check that
there is continuity between terminals 30 and 87.
4) If these conditions are not fulfilled, the remote
control is damaged and must be replaced.
TURN INDICATOR SWITCH
CHAR - 10
Desc./Quantity
reference in table
NGK ER9EH-N
12V - 9Ah
One 15A fuse - Two 7.5A fuses
single-phase alternating current
Vespa S 50 4T 4V (2008)
Characteristics
KEY SWITCH
LIGHT SWITCH
STARTER BUTTON
HORN BUTTON
CHAR - 11
Vespa S 50 4T 4V (2008)
Characteristics
STOP BUTTON
Resistance between green cable and ground connection: approx. 170 Ohm
- Primary resistance: 0.5 ÷ 0.6 Ohm
- Resistance between primary and ground connection: infinite
- Resistance between primary and HV output: 3 ÷
3.6 kOhm
- Shielded cap: 5000 Ohm
- Power: 120 W
- resistance between BLUE cable and GROUND
CONNECTION: 1 Ohm
Frame and suspensions
CHASSIS AND SUSPENSIONS
Specification
Type
CHAR - 12
Desc./Quantity
Unitised body made of stamped plate
Vespa S 50 4T 4V (2008)
Characteristics
Specification
Front suspension
Front suspension stroke
Trail (suspension rebounded/compressed)
Rear suspension
Rear suspension travel:
Desc./Quantity
Single arm suspension with swinging arm articulated to the
steering tube. Hydraulic double-acting shock absorber and coaxial spring
70 mm
71/68 mm
Single hydraulic double-acting shock absorber, helical coaxial
spring. Chassis to engine support with swinging arm.
83.5 mm
Brakes
BRAKES
Specification
Front
Rear
Desc./Quantity
Disc brake, Ø 200 mm
Drum brake, Ø 110 mm
Wheels and tyres
WHEELS AND TYRES
Specification
Front tyre size
Rear tyre size
Front tyre pressure
Rear tyre pressure:
Light alloy rims (Front rim)
Light alloy rims (rear rim)
Desc./Quantity
110/70"-11"
120/70-10"
1.6 bar
2 bar
2.50" x 11"
3.00 x 10"
N.B.
CHECK AND ADJUST TYRE PRESSURE WITH TYRES AT AMBIENT TEMPERATURE. ADJUST
PRESSURE ACCORDING TO THE WEIGHT OF RIDER AND ACCESSORIES.
Tightening Torques
STEERING ASSEMBLY
Name
Upper steering ring nut
Steering lower ring nut
Handlebar locking
Torque in Nm
30 ÷ 40
8 ÷ 10
50 ÷ 55 Nm
FRAME ASSEMBLY
Name
Engine-swinging arm bolt
Frame-swinging arm bolt
Shock absorber - chassis nut
Shock absorber nut-engine
Rear wheel nut
Screws fixing the odometer reel plate
Torque in Nm
33 ÷ 41
44 ÷ 52
20 ÷ 25
33 ÷ 41
104 ÷ 126
4÷6
FRONT SUSPENSION
Name
Shock absorber upper nut
Front wheel axle nut
Shock absorber upper bracket bolts
Wheel rim screws
Shock absorber lower bolts (°)
Torque in Nm
20 ÷ 30
75 ÷ 90
20 ÷ 25
20 ÷ 25
20 ÷ 27
(°) Lock these two bolts once the central upper nut of the shock absorber has been tightened.
CHAR - 13
Vespa S 50 4T 4V (2008)
Characteristics
N.B.
FOR SAFETY LOCKS, SEE THE «PRE-DELIVERY» CHAPTER.
FRONT BRAKE
Name
Brake fluid pump-hose fitting
Brake fluid pipe-calliper fitting
Screw tightening calliper to the support
Brake disc screw
Oil bleed valve (on the calliper)
Handlebar pump
Torque in Nm
8 ÷ 12
20 ÷ 25
20 ÷ 25
5 ÷ 6.5
10 ÷ 12
7 ÷ 10
ENGINE ASSEMBLY
Name
Ignition spark plug:
Floating head cover screws
Head-cylinder stud bolt nuts
Screws fixing head and cylinder to crankcase
Chain tensioner pad screw
Timing chain tensioner central screw
Camshaft pulley screw
Rocking lever axle and camshaft bearing screw
Rocking levers adjusting nuts:
Engine oil pre-filter cover:
Engine oil drainage cap
Flywheel nut
Stator screws
Pick-up screws
Oil pump bulkhead screw
Timing chain/oil pump compartment cover screws
Oil decantation labyrinth sheet screws
Oil pump crown screw
Screws fixing oil pump to the crankcase
Oil sump screws
Inlet manifold screw
Carburettor/manifold clamp screw
Screws fixing cables to starter motor
Starter screws
Transmission cover screws
Start-up lever screw
Crankcase cooling cover screw
Clutch assembly nut
Crankshaft pulley nut
Driven pulley shaft nut
Hub oil drainage screw
Rear hub cap screws
Crankcase half union screw
Torque in Nm
10 ÷ 15 Nm
6÷7
6 ÷ 7 + 90° + 90° *
8 ÷ 10
5 ÷ 7 Nm
5-6
12 ÷ 14
3 ÷ 4 Nm
7 ÷ 9 Nm
25 ÷ 28 Nm
25 ÷ 28
40 to 44 N.m
3÷4
3÷4
4÷5
4÷5
7÷8
8 ÷ 10
5÷6
8 ÷ 10 Nm
7÷9
1.2 ÷ 1.5
1.5 ÷ 2.5
11 ÷ 13
11 ÷ 13
11 ÷ 13
2 ÷ 2.5
55 ÷ 60
18 to 20 + 90° Nm
40 to 44 Nm
3 ÷ 5 Nm
11 ÷ 13
8 ÷ 10
* When assembling the new stud bolts, nut tightening involves 3 turns of 90° each after the first locking
at 6 ÷ 7 Nm, consequently: 6 ÷ 7 Nm + 90° + 90° + 90° at criss-crossed sequences.
Overhaul data
Assembly clearances
CHAR - 14
Vespa S 50 4T 4V (2008)
Characteristics
Cylinder - piston assy.
COUPLING BETWEEN PISTON AND CYLINDER
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
Piston 3rd oversize
Initials
A
B
C
D
A1
B1
C1
D1
A2
B2
C2
D2
A3
B3
C3
D3
Cylinder
38.993 ÷ 39.000
39.000 ÷ 39.007
39.007 ÷ 39.014
39.014 ÷ 39.021
39.193 ÷ 39.200
39.200 ÷ 39.207
39.207 ÷ 39.214
39.214 ÷ 39.221
39.393 ÷ 39.400
39.400 ÷ 39.407
39.407 ÷ 39.414
39.414 ÷ 39.421
39.593 ÷ 39.600
39.600 ÷ 39.607
39.607 ÷ 39.614
39.614 ÷ 39.621
Piston
38.954 ÷ 38.961
38.961 ÷ 38.968
38.968 ÷ 38.975
38.975 ÷ 38.982
39.154 ÷ 39.161
39.161 ÷ 39.168
39.168 ÷ 39.175
39.175 ÷ 39.182
39.354 ÷ 39.361
39.361 ÷ 39.368
39.368 ÷ 39.375
39.375 ÷ 39.382
39.554 ÷ 39.561
39.561 ÷ 39.568
39.568 ÷ 39.575
39.575 ÷ 39.582
Play on fitting
0.032 ÷ 0.046
0.032 ÷ 0.046
0.032 ÷ 0.046
0.032 ÷ 0.046
0.032 ÷ 0.046
0.032 ÷ 0.046
0.032 ÷ 0.046
0.032 ÷ 0.046
0.032 ÷ 0.046
0.032 ÷ 0.046
0.032 ÷ 0.046
0.032 ÷ 0.046
0.032 ÷ 0.046
0.032 ÷ 0.046
0.032 ÷ 0.046
0.032 ÷ 0.046
N.B.
THE PISTON MUST BE INSTALLED WITH THE ARROW FACING TOWARDS THE EXHAUST SIDE,
THE PISTON RINGS MUST BE INSTALLED WITH THE WORD «TOP» OR THE STAMPED MARK
FACING UPWARDS.
- Measure the outside diameter of the gudgeon
pin.
Characteristic
Pin outside diameter
13 +0 -0.004 mm
Minimum admissible diameter gudgeon pin
12.990 mm
CHAR - 15
Characteristics
Vespa S 50 4T 4V (2008)
- Measure the diameter of the bearings on the piston.
Characteristic
Pin seat diameter
13 +0.005 +0.010 mm
- Calculate the piston pin coupling clearance.
N.B.
THE PIN HOUSINGS HAVE 2 LUBRICATION CHANNELS. FOR THIS REASON, MEASUREMENT
MUST BE MADE ACCORDING TO THE PISTON AXIS.
Characteristic
Standard clearance
0.005 ÷ 0.014 mm
- Carefully clean the seal housings.
- Measure the coupling clearance between the
sealing 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.
N.B.
MEASURE THE CLEARANCE BY INSERTING THE BLADE
OF THE FEELER THICKNESS GAUGE FROM THE SECOND
SEAL SIDE.
Fitting clearance
Top piston ring - standard coupling clearance
0.03 ÷ 0.065 mm Top piston ring - maximum clearance allowed after use 0.07 mm Middle piston
ring - standard coupling clearance 0.02 ÷ 0.055
mm Middle piston ring - maximum clearance allowed after use 0.06 mm oil scraper ring - standard coupling clearance 0.04 ÷ 0.16 mm oil scraper
ring - maximum clearance allowed after use
0.17 mm
- Using a bore meter, measure the inner cylinder
diameter at three different points according to the
directions shown in the figure.
- Check that the coupling surface with the head is
not worn or misshapen.
CHAR - 16
Vespa S 50 4T 4V (2008)
Characteristics
- 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).
Characteristic
Maximum allowable run-out:
0.05 mm
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 thickness 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.
SEAL RINGS
Name
1st Compression ring
Description
Dimensions
39 x 1
Initials
A
Quantity
0.08 ÷ 0.20
CHAR - 17
Vespa S 50 4T 4V (2008)
Characteristics
Name
2nd Compression ring
Oil scraper ring
1st Compression ring
1st Oversize
2nd Compression ring
1st Oversize
Oil scraper ring 1st
Oversize
1st Compression ring
2nd Oversize
2nd Compression ring
2nd Oversize
Oil scraper ring 2nd
Oversize
1st Compression ring
3rd Oversize
2nd Compression ring
3rd Oversize
Oil scraper ring 3rd
Oversize
Description
Dimensions
39 x 1
39 x 2
39.2 x 1
Initials
A
A
A
Quantity
0.05 ÷ 0.20
0.20 ÷ 0.70
0.08 ÷ 0.20
39.2 x 1
A
0.05 ÷ 0.20
39.2 x 2
A
0.20 ÷ 0.70
39.4 x 1
A
0.08 ÷ 0.20
39.4 x 1
A
0.05 ÷ 0.20
39.4 x 2
A
0.20 ÷ 0.70
39.6 x 1
A
0.08 ÷ 0.20
39.6 x 1
A
0.05 ÷ 0.20
39.6 x 2
A
0.20 ÷ 0.70
Crankcase - crankshaft - connecting rod
AXIAL CLEARANCE BETWEEN CRANKSHAFT AND CRANKCASE
Name
Half-shaft, transmission
side
Flywheel-side half-shaft
Connecting rod
Spacer tool
Description
Dimensions
14 +0 -0.005
Initials
A
16 +0 -0.005
14.8 +0.05 -0
45.00 / Fits and clearances D = 0.15 ÷ 0.30
B
C
E
Characteristic
Clearance between crankshaft and connecting rod
A = 0.15 ÷ 0.30 mm
CHAR - 18
Quantity
Vespa S 50 4T 4V (2008)
Characteristics
Measure the bearings along X and Y axes
Characteristic
Crankshaft bearing, transmission side
20 -0.012 -0.025 mm
Crankshaft bearing, flywheel side
17 +0.007 0 mm
- 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.
Specific tooling
020074Y Support base for checking crankshaft alignment
CHAR - 19
Characteristics
Vespa S 50 4T 4V (2008)
- Install the crankshaft on the support and measure
the displacement at the 4 points shown in the figure.
N.B.
IF VALUES OTHER THAN THOSE ALLOWED ARE DETECTED, TRY STRAIGHTENING THE CRANKSHAFT BY INSERTING A WOODEN WEDGE BETWEEN THE HALF
SHAFTS OR BY CLOSING THEM WITH A VICE AS NEEDED. IF EVEN AFTER THIS OPERATION THE VALUES ARE
NOT THOSE ADMITTED, REPLACE THE CRANKSHAFT.
Characteristic
Off-line maximum admitted - A
0.15 mm
Off-line maximum admitted - B
0.02 mm
Off-line maximum admitted - C
0.02 mm
Off-line maximum admitted - D
0.10 mm
- Using a bore gauge, measure the connecting rod
small end diameter.
N.B.
IF THE CONNECTING ROD SMALL END DIAMETER EXCEEDS THE STANDARD DIAMETER, EXHIBITS WEAR OR
OVERHEATING, PROCEED TO REPLACE THE CRANKSHAFT AS DESCRIBED IN THE CRANKCASE AND
CRANKSHAFT CHAPTER.
Characteristic
Rod small end diameter
13 +0.015 + 0.025 mm
Max. diameter admitted: check the small end
13.030 mm
Calculate the coupling clearance between pin and rod small end
Characteristic
Pin - connecting rod clearance
0.015 ÷ 0.029 mm
Cylinder Head
Before performing head service operations, thoroughly clean all coupling surfaces. Note the position of
the springs and the valves so as not to change the original position during refitting
CHAR - 20
Vespa S 50 4T 4V (2008)
Characteristics
- Using a trued bar check that the cylinder head
surface is not worn or distorted.
- Check that the camshaft and rocking lever pin
bearings show no signs of wear.
- Check that the cylinder head cover surface, the
intake manifold and the exhaust manifold are not
worn.
- It is advisable to replace the head if any failure is
found.
Characteristic
Maximum allowable run-out:
0.1 mm
- 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.
Measure the camshaft bearing seats and rocking
lever support pins with a bore meter
HEAD CHECK
Specification
Standard diameter (mm) A
Standard diameter (mm) B
Standard diameter (mm) C
Desc./Quantity
Ø 32.015 ÷ 32.025 mm
Ø 16.0 ÷ 16.018
Ø 11.0 ÷ 11.018
CHAR - 21
Vespa S 50 4T 4V (2008)
Characteristics
Measure the unloaded spring length.
•
Standard length: 31.3 mm
•
Admissible limit after use: 29.3
- Clean the valve seats of any carbon residues.
- Using the Prussian blue, check the width of the
impression on the valve seat "V".
Characteristic
Standard value:
1 - 1.3 mm
Admissible limit:
1.6 mm
- If the impression width on the valve seat is larger than the prescribed limits, true the seats with a 45°
mill and then grind.
- In case of excessive wear or damages, replace the head.
STANDARD VALVE LENGTH
Specification
Inlet: standard length
Outlet: standard length
CHAR - 22
Desc./Quantity
74.9 mm
74.35 mm
Vespa S 50 4T 4V (2008)
Characteristics
- Measure the diameter of the valve stems in the
three positions indicated in the diagram.
STANDARD DIAMETER
Specification
Inlet
drainage
Desc./Quantity
3.970 ÷ 3.985 mm
3.960 ÷ 3.975 mm
MINIMUM DIAMETER PERMITTED
Specification
Inlet
drainage
Desc./Quantity
3.958 mm
3.945 mm
- Calculate the clearance between valve and valve guide.
- Check the concentricity of the valve head by arranging a dial gauge at right angle relative to the
valve head and rotate it on a "V" shaped abutment.
Characteristic
Admissible limit:
0.03 mm
- Check the deviation of the valve stem by resting
it on a «V» shaped abutment and measuring the
extent of the deformation with a dial gauge.
Characteristic
Limit values admitted:
0.1 mm
CHAR - 23
Vespa S 50 4T 4V (2008)
Characteristics
Measure the valve guides
VALVE GUIDE DIAMETER
Specification
Valve guide
Valve guide
Desc./Quantity
Standard diameter: 4 + 0.012 mm
Maximum admissible diameter: 4 + 0.022 mm
- After measuring the valve guide diameter and the
valve stem diameter, check clearance between
guide and stem.
INLET
Specification
Standard clearance
Admissible limit
Desc./Quantity
0.015 ÷ 0.042 mm
0.06 mm
OUTLET
Specification
Standard clearance
Admissible limit
Desc./Quantity
0.025 ÷ 0.052 mm
0.07 mm
- If no anomalies are found during the above checks, you can use the same valves. To obtain better
sealing performance, grind the valve seats. 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).
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.
CAUTION
DO NOT REVERSE THE FITTING POSITIONS OF THE VALVES (RIGHT - LEFT).
CHAR - 24
Vespa S 50 4T 4V (2008)
Characteristics
- Inspect the cam shaft for signs of abnormal wear
on the cams.
Characteristic
Standard diameter - Bearing A:
Ø 12 +0.002 +0.010
mm Standard
diameter - Bearing B:
Ø 16-0.015 -0.023 mm
Minimum diameter allowed - Bearing A:
Ø 11.98 mm
Minimum diameter allowed - Bearing B:
Ø 15.96 mm
-Using a gauge, measure the cam height.
Check the axial clearance of the camshaft
- 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.
N.B.
A BALL BEARING IS FITTED ON BEARING «A»; CONSEQUENTLY, BEARING «B» IS THE MOST IMPORTANT AS IT
WORKS DIRECTLY ON THE HEAD ALUMINIUM
Characteristic
Standard height - Inlet
24.397 mm
Standard height - Outlet
23.996 mm
Fitting clearance
Maximum admissible axial clearance: 0.5 mm
- Measure the outside diameter of the rocking lever pins
- Check the rocker pins do not show signs of wear or scoring.
- Measure the internal diameter of each rocking lever.
- Check that the pad in contact with the cam is not worn.
ROCKING LEVERS AND PIN DIAMETER:
Specification
Rocking levers - Inside diameter
Rocking levers - Pins diameter
Desc./Quantity
11.015 ÷ 11.035 mm
10.977 ÷ 10.985 mm
CHAR - 25
Vespa S 50 4T 4V (2008)
Characteristics
Slot packing system
Characteristic
Compression ratio
11.5 ÷ 12 : 1
PISTON PROTRUSION CHECK
Name
shimming_1
shimming_2
Measure A
1.7 ÷ 1.95
1.95 ÷ 2.2
Thickness
0.25
0.35
Products
RECOMMENDED PRODUCTS TABLE
Product
AGIP ROTRA 80W-90
Description
Rear hub oil
AGIP CITY HI TEC 4T
Oil to lubricate flexible transmissions
(brakes, throttle control and odometer)
Oil for air filter sponge
AGIP FILTER OIL
AGIP CITY HI TEC 4T
AGIP GREASE MU3
AGIP BRAKE 4
MONTBLANC MOLYBDENUM
GREASE
AGIP GREASE PV2
AGIP GP 330
CHAR - 26
Specifications
SAE 80W/90 Oil that exceeds the requirements of API GL3 specifications
Oil for 4-stroke engines
Mineral oil with specific additives for increased adhesiveness
Engine oil
SAE 5W-40, API SL, ACEA A3, JASO MA
Synthetic oil
Grease for odometer transmission gear Soap-based lithium grease with NLGI 3;
case
ISO-L-XBCHA3, DIN K3K-20
Brake fluid
FMVSS DOT 4 Synthetic fluid
Grease for driven pulley shaft adjusting
Grease with Molybdenum disulphide
ring and movable driven pulley housing
Grease for steering bearings, bolt seatSoap-based lithium and zinc oxide
ings for swinging arms and faying surface
grease containing NLGI 2; ISO-Lof driven pulley spring (only pulley side)
XBCIB2
Grease for brake levers, throttle
White calcium complex soap-based
spray grease with NLGI 2; ISO-L-XBCIB2
INDEX OF TOPICS
TOOLING
TOOL
Vespa S 50 4T 4V (2008)
Tooling
TOOLS
TOOL - 28
Stores code
001467Y008
Description
Pliers to extract 17 mm ø bearings
001467Y029
Bell for bearings, O.D. 38 mm
004499Y
Bearing extractor. Fitted with: 1 Bell, 2
Sleeve, 3 Screw, 6 Ring, 27 Half rings, 34
Half rings
005095Y
Engine support
008119Y009
Tube to assemble shafts and axles
020004Y
Punch for removing fifth wheels from
headstock
Vespa S 50 4T 4V (2008)
Tooling
Stores code
020055Y
Description
Wrench for steering tube ring nut
020074Y
020150Y
Tool to align crankshaft
Air heater support
020151Y
Air heater
020162Y
Flywheel extractor
020171Y
Punch for driven pulley roller bearing
020265Y
Bearing fitting base
TOOL - 29
Vespa S 50 4T 4V (2008)
Tooling
TOOL - 30
Stores code
020288Y
Description
Fork to assemble piston on cylinder
020291Y
Valve fitting/ removal tool
020306Y
Punch for assembling valve seal rings
020329Y
MityVac vacuum-operated pump
020330Y
Stroboscopic light to check timing
020331Y
Digital multimeter
Vespa S 50 4T 4V (2008)
Tooling
Stores code
020332Y
Description
Digital rpm indicator
020334Y
Multiple battery charger
020335Y
Magnetic support for dial gauge
020340Y
Flywheel and transmission oil seals fitting
punch
020358Y
020359Y
37x40-mm Adaptor
42x47-mm Adaptor
TOOL - 31
Vespa S 50 4T 4V (2008)
Tooling
TOOL - 32
Stores code
020360Y
Description
52x55-mm Adaptor
020362Y
12 mm guide
020363Y
20-mm guide
020364Y
25-mm guide
020376Y
Adaptor handle
020431Y
Valve oil seal extractor
Vespa S 50 4T 4V (2008)
Tooling
Stores code
020432Y
Description
Tool to fit the start-up sector spring
020439Y
17 mm guide
020444Y
020448Y
Pin fitting/removal tool
Pin lock fitting tool
020449Y
Piston position check support
020450Y
Camshaft fitting/removal tool
020451Y
020452Y
Driving pulley lock wrench
Tube for removing and refitting the driven
pulley shaft
TOOL - 33
Vespa S 50 4T 4V (2008)
Tooling
TOOL - 34
Stores code
020456Y
Description
Ø 24 mm adaptor
020565Y
Flywheel lock calliper spanner
020683Y
Valve pressing member
INDEX OF TOPICS
MAINTENANCE
MAIN
Vespa S 50 4T 4V (2008)
Maintenance
Maintenance chart
SCHEDULED MAINTENANCE TABLE
I: CHECK AND CLEAN, ADJUST, LUBRICATE OR REPLACE IF NECESSARY.
C: CLEAN, R: REPLACE, A: ADJUST, L: LUBRICATE
* Replace every 2 years
Km x 1000
Safety locks
Spark plug
Driving belt
Throttle control
Tyre condition and
wear
Air filter
Oil filter (mesh)
Solenoid filter
Valve clearance
Electrical system
and battery
Cylinder ventilation system
Brake control levers
Brake oil level (*)
Hub oil level
Engine oil
Brake Pads/Shoes
Tyre pressure
Headlight
Vehicle test drive
Idle speed
Odometer gear
Variable speed
rollers
Suspensions
Steering
Transmissions
1
I
3
6
9
R
I
A
15
I
18
21
R
I
C
C
C
I
I
C
C
I
I
12
I
R
R
A
I
24
I
R
R
A
I
I
30
33
R
I
C
C
C
I
I
C
C
36
I
R
R
A
I
39
I
45
R
I
C
C
C
I
I
C
C
42
L
I
R
R
I
I
L
I
I
A
I
I
R
I
I
I
I
A
I
I
R
R
I
I
A
I
A
L
R
I
I
I
I
I
R
R
I
I
A
I
A
L
R
I
A
L
The carburettor features a solenoid valve "A" that,
via an ECU, manages an extra flow of air.
It is connected to the carburettor via flexible pipes
as shown in the figure.
The valve is placed under the helmet compartment
as shown in the picture.
Pipe "B" is coupled to a filter placed inside the
body. The solenoid filter should be cleaned according to the kilometres travelled as instructed in
the scheduled maintenance chart.
I
A
L
51
I
54
57
R
I
60
I
R
R
A
I
C
C
C
I
I
C
C
I
I
L
I
I
R
I
I
48
I
R
R
A
I
C
C
C
I
I
C
C
I
Carburettor
MAIN - 36
27
L
I
I
I
R
I
I
I
I
I
I
R
R
I
I
A
I
A
L
R
I
A
L
L
I
I
I
R
I
I
I
I
I
I
R
R
I
I
A
I
A
L
R
I
A
L
L
I
I
I
R
I
I
I
I
I
I
R
R
I
I
A
I
A
L
R
I
A
L
Vespa S 50 4T 4V (2008)
Maintenance
- 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 valve in case of wear due to
excessive clearance.
- 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
1. Needle valve - 2. Idle speed adjustment screw - 3. Max jet - 4. Accelerating pump - 5. Tapered pin 6. Jet holder - 7. Float - 8. Chamber - 9. Starter device - 10. Vacuum valve - 11. Cover - 12. Minimum
jet.
MAIN - 37
Maintenance
Vespa S 50 4T 4V (2008)
Checking the spark advance
The vehicle is fitted with a variable advance electronic device. There are two timing references on
the flywheel cover in order to ensure a better precision when detecting the reference on the fan.
CAUTION
SHOULD THE FLASH INDICATIONS BE UNSTABLE AND
THE RPM INDICATION DOES NOT CORRESPOND WITH
THE TRUE ENGINE SPEED VARIATION (FOR EXAMPLE,
VALUES SHOWN ARE HALVED), INSTALL A 10 ÷ 15 KΩ
RESISTIVE CABLE CONNECTED IN SERIES TO AN HV CABLE. IF THE IRREGULAR READING CONTINUES AFTER
THIS OPERATION, CHECK THE COMPONENTS OF THE
IGNITION SYSTEM.
When the advance check is carried out with a stroboscopic gun, add 10° flywheel keying to the table
below.
Spark plug
Disconnect and remove the spark plug tube.
- Examine it carefully and replace it if the insulator
is chipped or cracked.
- Measure electrode gap with a thickness gauge
and, if necessary, adjust the gap by carefully bending the outer electrode forward or away.
- Make sure the sealing washer is in good conditions.
MAIN - 38
Vespa S 50 4T 4V (2008)
Maintenance
- Fit the spark plug, screw it manually and lock it
to the prescribed torque with a spark plug spanner.
Electric characteristic
Candela
NGK ER9EH-6N
Distanza elettrodi:
0,6 mm
Locking torques (N*m)
Candela 8 ÷ 10
Hub oil
Check
Rest the vehicle on its centre stand on an even
surface.
- Unscrew the oil dipstick "A", dry it with a clean
cloth and reinsert it, screwing it in thoroughly.
- Pull out the dipstick and check that the oil level is
above the "middle" notch (dipstick with 3 notches).
For dipsticks with 2 notches, the oil level must remain in the lower half of the dipstick.
-Screw up the oil dipstick again and make sure it
is locked properly into place.
Recommended products
AGIP ROTRA 80W-90 rear hub oil
SAE 80W/90 Oil that exceeds the requirements of
API GL3 specifications
MAIN - 39
Maintenance
Replacement
Remove the oil filler cap/dipstick "A".
- Unscrew the oil drainage plug "B" shown in the
figure and drain out all the oil.
- Screw the drainage plug back and fill up the hub
with the required oil (about 100 cm³)
Air filter
Once the lower section of the left side cover has
been removed, take out the air cleaner cap by unscrewing the 4 fixing screws and the 2 knobs (they
can be reached by tipping the saddle and removing the helmet compartment); afterwards, remove
the filtering element.
Cleaning:
- Wash with water and car shampoo;
- Dry with a clean cloth and short blasts of compressed air; do not wring;
- Immerse it in a mixture of 50% oil and 50 % petrol.
- Allow the filtering element to drip dry and then
press it in your hands but without squeezing.
CAUTION
NEVER RUN THE ENGINE WITHOUT THE AIR FILTER,
THIS WOULD RESULT IN AN EXCESSIVE WEAR OF THE
PISTON AND CYLINDER.
Engine oil
MAIN - 40
Vespa S 50 4T 4V (2008)
Vespa S 50 4T 4V (2008)
Maintenance
Replacement
Loosen the oil filler plug.
- Unscrew the drainage plug from the mesh filter
on the flywheel side, and let the oil drain off.
- Tighten the drainage plug and refill with ~
600-650 cm³ of oil.
Check
Park the vehicle on a level surface and rest it on
its stand (cold engine).
- Check that the oil level is between the MAX and
MIN marks on the dipstick.
- The MAX level reference indicates ~ 850 cm³ in
the engine.
- If the oil level is close to the MIN mark, top-up by
adding oil but do not exceed the MAX level.
Recommended products
AGIP CITY HI TEC 4T Oil to lubricate flexible
transmissions (brakes, throttle control and odometer)
Oil for 4-stroke engines
Engine oil filter
- Change oil when the engine is hot.
- Place a container under the oil sump and remove
the oil drainage cap.
- After draining the oil, clean the mesh filter with a
specific solvent and then blow it with compressed
air.
- The filter can be reached after removing cap
"A" (see figure).
MAIN - 41
Maintenance
- After this operation, refit the filter and screw the
oil cap at the prescribed torque using a new ORing
- Refill the engine with oil through the oil filling hole
located in the oil sump.
- Engine oil capacity: ~ 850 cc.
- Lock the cap manually.
N.B.
Run the engine for a couple of minutes and check the oil level
when the engine is cold. The level should always be below the
MAX mark
N.B.
For the first top-up or when servicing, add 850 cm³ of engine
oil; for any other case, add 650 cm³ and top-up, if required.
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
Locking torques (N*m)
Engine oil pre-filter cover 25 ÷ 28 Nm
Checking the ignition timing
- Turn the flywheel clockwise until its 2nd notch
coincides with the Pick-up reference mark as
shown in the figure.
Make sure that the reference point on the camshaft
command crown is aligned with the reference point
on the head as shown in the second figure.
If the reference is opposite the indicator on the
head, turn the crankshaft once more as the piston
must be at the TDC of the bursting phase.
N.B.
TIME THE TIMING SYSTEM UNIT AS DESCRIBED IN CHAPTER 6 IF IT IS NOT IN PHASE
MAIN - 42
Vespa S 50 4T 4V (2008)
Vespa S 50 4T 4V (2008)
Maintenance
Checking the valve clearance
- Remove the spark plug access cover, undo the
4 fixing screws indicated in the figure and remove
the tappet cover.
- To check valve clearance, centre the reference
marks of the timing system point as described
above.
- Use a thickness gauge to check valve clearance
- If the valve clearance values, inlet and outlet respectively, differ from those indicated below, replace the calibrated pads in order to restore the
correct valve clearance.
Characteristic
Inlet (with cold engine)
0.10 mm
Outlet (with cold engine)
0.15 mm
Headlight adjustment
Proceed as follows:
1. Place the vehicle, in running order and with the
tyres inflated to the prescribed pressure, on a flat
surface 10-m away from a white screen situated in
a shaded area, making sure that the longitudinal
axis of the scooter is perpendicular to the screen;
2. Turn on the headlight and check that the borderline of the projected light beam on the screen
is not lower than 9/10 of the distance from the
ground to the centre of vehicle headlamp and higher than 7/10;
3. If otherwise, adjust the right headlight with screw
«A».
N.B.
THE ABOVE PROCEDURE COMPLIES WITH THE EUROPEAN STANDARDS REGARDING MAXIMUM AND MINIMUM HEIGHT OF LIGHT BEAMS. REFER TO THE STATUTORY REGULATIONS IN FORCE IN EVERY COUNTRY
WHERE THE VEHICLE IS USED.
MAIN - 43
Maintenance
SAS filters inspection and cleaning
Undo the two screws «A» of the side fairing and
remove the fairing. Undo the three screws «B» and
remove the housing cover of the secondary air
system. Detach the housing cover and remove the
filtering element «C» made of sponge. Wash the
sponge with water and neutral soap, then dry with
a clean cloth and short blasts of compressed air.
While cleaning the filter, check the condition of the
reed valve «D», and fit it back in place on the
housing.
Before closing the cover of the SAS housing,
check the good condition of the sealing O-ring; replace it if damaged or deformed.
N.B.
The reed valve can be inserted in only one direction on the
SAS housing
MAIN - 44
Vespa S 50 4T 4V (2008)
INDEX OF TOPICS
TROUBLESHOOTING
TROUBL
Vespa S 50 4T 4V (2008)
Troubleshooting
Engine
Poor performance
POOR PERFORMANCE
Possible Cause
Air filter obstructed or dirty.
Carburettor nozzles clogged or dirty
Dirty or faulty vacuum-operated cock
Clutch slipping
Inefficient automatic transmission
Lack of compression: parts, cylinder and valves worn
Oil level exceeds maximum
Excess of encrustations in the combustion chamber
Incorrect timing or worn timing system elements
Muffler obstructed
Fuel filter on vacuum operated cock blocked
Wrong valve adjustment
Valve seat distorted
Worn cylinder, Worn or broken piston rings
Operation
Dismantle the sponge, wash with water and shampoo, then
soak it in a mixture of 50% petrol and 50% Selenia Air Filter Oil,
then allow to drip dry. Wring out water manually without
squeezing and reassemble.
Dismantle, wash with solvent and dry with compressed air
Check the filter on the cock, remove the petrol and wash the
tank, if necessary. Replace the cock as a last resource.
Check the clutch system and/or the bell and replace if necessary
Check the rollers and the pulley movement, replace the damaged parts and lubricate the driven pulley moveable guide with
Montblanc Molybdenum Grease
Replace the worn parts
Check for causes and fill to reach the correct level
Descale the cylinder, the piston, the head and the valves
Time the system again or replace the worn parts (see 50 4T
Engines manual)
Replace
Clean the cock filter
Adjust the valve clearance properly
Replace the head assembly
Replace the piston cylinder assembly or just the piston rings
Rear wheel spins at idle
REAR WHEEL
Possible Cause
Idling rpm too high
Clutch fault
Air filter housing not sealed
Purifier-carburettor fitting damaged
Operation
Check the idling speed and, if necessary, adjust the C.O.
Check the spring/friction mass and the clutch bell
Correctly refit the filter housing and replace it if it is damaged
Replace
Starting difficulties
START-UP PROBLEMS
Possible Cause
Defective spark plug or with incorrect electrode gap
Battery flat
- Engine flooded.
Vacuum operated cock failure
TROUBL - 46
Operation
Check and if necessary replace the spark plug and the electrode gap
Check the state of the battery. If it shows signs of sulphation
replace it and bring the new battery into service charging it for
eight hours at a current of 1/10 of the capacity of the battery
itself
Start the vehicle keeping the throttle fully open alternately making the engine run for approx. five seconds and stopping for
other five seconds. If however it does not start, remove the
spark plug, the engine over with the throttle open being careful
to keep the cap in contact with the spark plug and the spark
plug grounded but away from its hole. Refit a dry spark plug
and start the vehicle.
Check that fuel is adequately supplied through the pipe by applying a vacuum to the suction pipe
Vespa S 50 4T 4V (2008)
Troubleshooting
Possible Cause
Failing automatic starter on the carburettor
Wrong ignition advance
Incorrect valve sealing or valve adjustment
Rpm too low at start-up or engine and start-up system damaged
Altered fuel characteristics
Carburettor nozzles clogged or dirty
Operation
Check the electrical wiring and mechanical movement, replace
if necessary.
Check flywheel keying on the crankshaft, replace control unit if
necessary
Inspect the head and/or restore the correct clearance
Check the starter motor and the system.
Drain off the fuel no longer up to standard; then, refill
Dismantle, wash with solvent and dry with compressed air
Engine tends to cut-off at full throttle
ENGINE STOP FULL THROTTLE
Possible Cause
Maximum jet clogged
Water or condensation in the carburettor chamber
Incorrect ignition advance
Air filter blocked or dirty.
Incorrect float level
Fuel supply pipes choked or clogged
Tank breather hole obstructed
Level in chamber too low
Operation
Remove the carburettor, wash with solvent and dry with compressed air
Remove the chamber, wash with solvent and dry with compressed air or empty the tank through the appropriate bleed
screw
Use a stroboscopic light to check ignition advance and the flywheel correct keying
Dismantle the sponge, wash with water and shampoo, then
soak it in a mixture of 50% petrol and 50% of specific oil (Selenia Air Filter Oil), then hand dry without squeezing, allow to
drip dry and then reassemble.
Restore the correct level in the chamber (the float must be parallel to the upper cover contact plane, that is the throttle valve
membrane cover)
Restore the adequate fuel supply
Restore the proper reservoir aeration
Restore the correct level in the chamber (the float must be parallel to the upper cover contact plane, that is the throttle valve
membrane cover)
Engine tends to cut-off at idle
ENGINE STOP IDLING
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.
Wrong idling adjustment
Spark plug defective or faulty
Pressure too low at the end of compression
Incorrect timing
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 correct level in the chamber (the float must be parallel to the upper cover contact plane, that is the throttle valve
membrane cover)
Check that the small piston slides smoothly and check the automatic starter power supply; replace it if required
Dismantle the sponge, wash with water and shampoo, then
soak it in a mixture of 50% petrol and 50% of specific oil (Selenia Air Filter Oil), then hand dry without squeezing, allow to
drip dry and then reassemble.
Correctly adjust the engine idling and check the level of the
C.O.
Replace the spark plug with one with the specified degree and
check the plug gap
Check the thermal group seals and replace worn components
Time the system and check the timing system components
TROUBL - 47
Vespa S 50 4T 4V (2008)
Troubleshooting
High fuel consumption
EXCESSIVE FUEL CONSUMPTION
Possible Cause
Air filter blocked or dirty.
Operation
Dismantle the sponge, wash with water and shampoo, then
soak it in a mixture of 50% petrol and 50% of specific oil (Selenia Air Filter Oil), then hand dry without squeezing, allow to
drip dry and then reassemble.
Check that the starter runs correctly and it is properly powered
Check the maximum and minimum nozzles are adequately
fixed in their fittings
Check and restore the correct fuel level in the chamber
The starter remains on
Loose nozzles
Incorrect float level
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 faying surface with the bell 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
Possible Cause
Worn brake pads or shoes
Air bubbles inside the hydraulic braking system
Brake disc or drum deformed
Fluid leakage in hydraulic braking system
Excessive backlash in the rear brake control cable
The brake fluid has lost its properties
Return spring broken
Shoe control bolt not lubricated
Operation
Replace the brake pads or shoes and check for brake disk or
drum wear conditions.
Carefully bleed the hydraulic braking system, (there must be
no flexible movement of the brake lever).
Use a dial gauge to check the levelness of the disk with the
wheel correctly fitted and the concentricity of the rear drum;
check the brake disc screws are locked
Elastic fittings, piston seals or brake pump breakdown, replace
Adjust backlash with the appropriate adjuster on the shoe control lever
Replace the front brake fluid and top up to the correct level in
the pump
Replace spring.
Lubricate with Z2 grease.
Brakes overheating
BRAKES OVERHEATING
Possible Cause
Defective plunger sliding
Brake disc or drum deformed
TROUBL - 48
Operation
Check calliper and replace any damaged part.
Use a dial gauge to check the levelness of the disk with the
wheel correctly fitted and the concentricity of the rear drum;
check the brake disc screws are locked
Vespa S 50 4T 4V (2008)
Troubleshooting
Electrical system
Battery
BATTERY
Possible Cause
Operation
The battery is the electrical device in the system that requires The battery is the electrical device in the system that requires
the most frequent inspections and thorough maintenance.
the most frequent inspections and 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 5 ÷ 6 months. If the battery is fitted
on a motorcycle, be careful not to invert the connections, keeping in mind that the black earth wire is connected to the negative
terminal while the red wire is connected to the terminal marked
+.
Turn signal lights malfunction
ELECTRICAL SYSTEM MALFUNCTION
Possible Cause
Turn indicators do not turn on
Operation
Check turn indicators device and/or wiring as described in the
«Electrical system» chapter.
Steering and suspensions
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: replace them if they are recessed or if the balls are flattened.
Excessive steering play
EXCESSIVE STEERING CLEARANCE
Possible Cause
Excessive steering clearance
Operation
Check the tightening of the top ring nut. If irregularities continue
in turning the steering even after making the above adjustments, check the seats in which the ball bearings rotate: replace if they are recessed.
Noisy suspension
NOISY SUSPENSION
Possible Cause
Noisy suspension
Operation
If the front suspension is noisy, check: that the front shock absorber works properly and the ball bearings are good condition.
TROUBL - 49
Vespa S 50 4T 4V (2008)
Troubleshooting
Possible Cause
Operation
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.
Check that the swinging arm connecting the engine to the
chassis and the rear shock absorber work properly
Suspension oil leakage
OIL LEAKAGE FROM SUSPENSION
Possible Cause
Oil leakage from suspension
TROUBL - 50
Operation
Replace the damper.
INDEX OF TOPICS
ELECTRICAL SYSTEM
ELE SYS
Vespa S 50 4T 4V (2008)
Electrical system
Instruments and warning lights control board
INSTRUMENT BOARD - WARNING LIGHTS AND INSTRUMENT PANEL
1
2
3
4
5
6
7
8
9
Specification
Left turn indicator warning light
High-beam warning light
Fuel gauge
Instrument panel lighting bulbs
Headlight warning light
Low fuel warning light
Right turn indicator warning light
Instrument panel lighting bulbs
Pre-set warning light
Checks and inspections
In case the cause of ignition failure or malfunction
cannot be easily identified at sight, first of all replace the control unit by another one in operating
conditions.
Remember that the engine must be off to disconnect and replace the control unit.
If after replacement the vehicle starts properly, the
control unit is failing and must be replaced.
If the failure persists, check the generator and the
stator components as follows:
After visually checking the electrical connections,
use a specific tester to measurement the stator
winding and the pickup (see table).
If any failure is found after checking the loading coil
and the pick-up, replace the stator and the damaged parts.
ELE SYS - 52
Desc./Quantity
12V - 2W
12V - 1.2W
12V - 1.2W
12V 1.2W
12V - 1.2W
12V - 2W
12V - 2W
Vespa S 50 4T 4V (2008)
Electrical system
Disconnect the connector on the flywheel cover
and measure the resistance between either contact and the earthing.
Specific tooling
020331Y Digital multimeter
PICK-UP CHECK
1
Specification
1) Brown cable and earth
1
Specification
1) Black cable and earth
Desc./Quantity
~ 170 Ω
STATOR WINDING CHECK
Desc./Quantity
~1Ω
Ignition circuit
All the control operations of the system that require the disconnection of cables (checks of the connections and the devices making up the ignition circuit) must be done with the engine off: if this is not done,
the controls might be irretrievably damaged.
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:
- Check the Pick-Up.
Disconnect the electronic starter connector and
check continuity between terminal No. 3 (Green)
and terminal No. 4 (Black).
The check includes the Pick-Up and its power line.
If a break in the circuit is found, check again the
flywheel and the engine earth connectors. If nonconforming values are measured, replace the
Pick-Up; otherwise, repair the cable harness.
ELE SYS - 53
Electrical system
Vespa S 50 4T 4V (2008)
Electric characteristic
Pick - up resistance
approx. 170 Ohm
- HV primary coil check
Disconnect the electronic starter connector and
check continuity between terminal No. 3 (purple)
and terminal No. 1 (black) (see figure).
If non-conforming values are measured, check
again the HV coil primary directly on the positive
and negative terminals.
If the values are correct, repair the cable harness
or reset the connections; otherwise, replace the
HV coil
Electric characteristic
HV coil primary resistance
0.5 ÷ 0.6 Ohm
- 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
HV coil secondary resistance
3000 ÷ 3600 Ohm
ELE SYS - 54
Vespa S 50 4T 4V (2008)
Electrical system
- Pick-Up
Disconnect the ECU connector and connect the
positive terminal to connector No. 3 (green) and
the negative terminal to connector No. 4 (black).
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
Pick-Up voltage value
Pick-Up voltage value: > 2 Volt
- H.V. coil
With the electronic starter and the HV coil connected to the system, measure the voltage of the coil
primary during the start-up test with the voltage
peak adaptor and by connecting the positive terminal to the ground lead and the negative terminal
to the coil positive connector.
If non-conforming values are measured, replace
the control unit.
THE POSITIVE TERMINAL OF THE HV COIL PRIMARY IS
BLACK.
Electric characteristic
High voltage coil voltage value
High voltage coil voltage value: > 100 Volt
Stator check
- Using a tester, check the resistance between the
brown-earth and black-earth terminal.
N.B.
VALUES ARE STATED AT AMBIENT TEMPERATURE. A
CHECK WITH THE STATOR AT OPERATING TEMPERATURE LEADS TO VALUES HIGHER THAN THOSE STATED.
Electric characteristic
Stator : Brown-earth
approx. 170 Ω (Pick-Up)
Stator : Black-earth
ELE SYS - 55
Electrical system
Vespa S 50 4T 4V (2008)
~ 1 Ω (Stator)
Voltage regulator check
A malfunction in the voltage regulator might cause the following problems depending on the type of
fault:
1) Bulbs burned out (regulator in short circuit).
2) Malfunction of the lighting system and the electric starter (regulator interrupted).
3) Battery not recharging.
4) Turn indicators not working.
The regulator is earthed through the electrical system, so the regulator body does not earth the circuits
inside the regulator.
There must be insulation between each regulator terminal and the regulator body (use the tester to
check electric resistance).
2) LIGHTS AND STARTER NOT WORKING
Gain access to the voltage regulator by removing
the plastic cover on the legshield; start the engine
and keep running it at idle speed.
Connect the tester positive probe to terminal No.
1 (yellow cable) and the negative probe to terminal
No. 2 (black cable); check if there is voltage.
If there is voltage, check that the light remote control and its excitation line, coming from the electronic starter (sky blue PIN 7 - purple PIN 3) work
properly. Check the cable harness from the light
switch to the remote control and whether the
switch works properly .
If no voltage is detected, try connecting the negative probe directly to earth; if voltage is detected
with this operation, check the earth wiring of the
regulator; otherwise, replace the regulator because it is failing.
As a last check, the voltage supplied by the stator
can be measured:
- Disconnect the regulator connector and place a
tester to detect alternating voltage between the
Blue cable (4) and the ground connection (see figure).
ELE SYS - 56
Vespa S 50 4T 4V (2008)
Electrical system
- Voltage supplied at 2000 rpm must be about 25
÷ 35V.
If no value is obtained even with this test, replace
the regulator because it is obviously failing.
N.B.
TO MEASURE THE ABOVE VOLTAGE USE AN ANALOGUE
TESTER THAT CAN MEASURE ALTERNATING VOLTAGES AND KEEP THE ENGINE AT IDLE TO HAVE AN ALTERNATING VOLTAGE OF A FREQUENCY AS CLOSE AS
POSSIBLE TO 50HZ SO AS TO DETECT THE EFFICIENT
VOLTAGE VALUE SUPPLIED BY THE REGULATOR
(ABOUT 12V).
Recharge system voltage check
3) BATTERY NOT RECHARGING
A failure in the direct current section of the voltage
regulator may cause the following problems depending on the type of fault:
a) Protection fuse blows due to overvoltage
(regulator in short circuit) and consequently
the battery fails to recharge.
b) Battery fails to recharge (regulator interrupted).
Measures
a) Protection fuse blows (regulator in short circuit).
Check that the cable harness going from the protection fuse to the key switch is not damaged,
which may cause a short circuit to ground (thus
preventing damaging the regulator).
Afterwards measure the resistance between contact 3 (Orange) and contact 2 (Black) of the voltage
regulator (with connector disconnected)
If the value measured is far from that indicated,
replace the regulator because it is in short circuit.
b) Battery fails to recharge (regulator interrupted).
To check if there is any failure in the voltage regulator recharge section, first connect 2 testers to
the battery (one to detect voltage and the other to
detect current) as indicated in the second figure
and follow the procedure below:
ELE SYS - 57
Electrical system
Start the engine (temporarily connect the red cable
to the battery positive terminal in order to avoid
damaging the device that measures current).
Check that there is a 13V voltage minimum (battery charged) and a recharge current of 1.5 ÷ 2A
with the lighting system but the starter disabled. To
disable the lighting system, remove the light remote control.
As the engine rpm increases, so do the current and
the recharge voltage; with rpm over 4000 there
must be a recharge current of about 4.5A; enabling
both the lighting system and the starter, the stop
light and if the horn is powered, current values ≥
5A and a voltage value of 14 ÷ 14.5V ( regulator
threshold voltage) can be found.
If values other than those above are detected,
replace the regulator; contrariwise, check the
cable harness and the connections.
Electric characteristic
Voltage regulator resistance
~ 8 MΩ
Turn signals system check
4) TURN INDICATORS NOT WORKING
If the turn indicators do not work, do the following:
- Remove the regulator connector and place the
tester probes between the orange cable (3) and
the black cable (2).
- Turn the key switch to ON and check that the
battery is getting voltage. If no voltage is detected,
repeat the test now between the orange cable and
the ground lead. If there is no voltage even after
this operation, check the cable harness and the
contacts of the key switch and the battery. Conversely, if battery voltage is detected (black cable),
check the regulator ground cable harness.
ELE SYS - 58
Vespa S 50 4T 4V (2008)
Vespa S 50 4T 4V (2008)
Electrical system
- If the above tests have positive results, jump contacts 5 (blue/black) and 3 (white) on the connector,
set the key switch to ON and turn the turn indicator
switch to the left and right to see when the lights
are steadily on (as they are directly powered by the
battery).
If even after this operation the turn indicators fail
to turn on, check that the wiring is not damaged
and the switch works properly. If these last two
tests have a positive result, replace the regulator
because it is certainly not functioning properly.
Specific tooling
020331Y Digital multimeter
Connectors
ELECTRONIC STARTER
SECTION "A"
1. HV COIL CONTROL
2. KEY SWITCH CONTACTS TO GROUND
3. HV COIL POSITIVE
SECTION "B"
1. KEY POSITIVE
2. STARTER POWER SUPPLY
3. PICK UP SIGNAL
4. GROUND
5. SOLENOID VALVE
6. NTC TEMPERATURE SENSOR
7. LIGHT REMOTE CONTROL
8. DIAGNOSIS SOCKET
ELE SYS - 59
Electrical system
VOLTAGE REGULATOR
1. LIGHTING SYSTEM POWER SUPPLY (alternating)
2. GROUND
3. BATTERY POSITIVE
4. FROM FLYWHEEL (alternating)
5. TURN INDICATORS
ELE SYS - 60
Vespa S 50 4T 4V (2008)
INDEX OF TOPICS
ENGINE FROM VEHICLE
ENG VE
Engine from vehicle
Vespa S 50 4T 4V (2008)
Exhaust assy. Removal
- Remove the 2 fixing nuts from the manifold to the
head
- Undo the 2 screws fixing the muffler to the housing; then remove the whole muffler paying attention to the interference between its supporting
bracket and the cooling cover.
Removal of the engine from the vehicle
Removing the engine from the chassis
-Disconnect the battery.
-Remove the muffler assembly.
- Remove the rear wheel.
- Remove the rear brake mechanical transmission.
-Disconnect the electric terminals.
-Remove the throttle grip transmission.
- Disconnect the tubing (petrol-vacuum operated cock control).
- Disconnect the swinging arm on the engine side
- Disconnect the rear shock absorber lower clamping
WARNING
Be very careful when handling fuel.
CAUTION
When installing the battery, first attach the positive cable and then the negative cable.
WARNING
Wear safety goggles when using hitting tools.
ENG VE - 62
INDEX OF TOPICS
ENGINE
ENG
Engine
Automatic transmission
Transmission cover
- Remove the 12 fixing screws.
- Remove the oil filling cap and then slide out the
cover.
If this operation is carried out directly on the vehicle, it is necessary to remove the transmission
cooling coupling and the air filter housing retainers.
N.B.
USE A MALLET ON THE APPROPRIATE COUPLINGS TO
REMOVE THE COVER.
Kickstart
-To remove the start up pinion push the starter
lever to facilitate extracting the pinion.
-Remove the kick-start screw and lever.
-Remove the Seeger ring and the washer indicated in the figure.
-Pull out the toothed sector.
WARNING
THE SECTOR KEEPS THE SPRING SET, BE CAREFUL SO
AS NOT TO CAUSE ANY ACCIDENTS
Air duct
- To remove the intake throat on the transmission
cover, just remove the three fixing screws indicated in the figure.
ENG - 64
Vespa S 50 4T 4V (2008)
Vespa S 50 4T 4V (2008)
Engine
Removing the driven pulley shaft bearing
- Slightly heat the crankshaft from the inside side
to avoid damaging the coated surface and use the
driven pulley shaft or a pin of the same diameter
to remove the bearing.
N.B.
IN CASE OF DIFFICULTY A STANDARD 8MM-INSIDE DIAMETER EXTRACTOR CAN BE USED.
Refitting the driven pulley shaft bearing
Refit the bearing with the aid of a bushing with the same diameter as the external plate of the bearing
after slightly heating the crankcase from the inside.
N.B.
WHEN REFITTING, ALWAYS REPLACE THE BEARING WITH A NEW ONE.
CAUTION
WHEN REMOVING/REFITTING THE BEARING, TAKE CARE NOT TO DAMAGE THE COVER
PAINTED SURFACE.
Removing the driven pulley
- Lock the clutch bell housing with the specific tool.
- Remove the nut, the clutch bell housing and the
whole of the driven pulley assembly.
N.B.
THE UNIT CAN ALSO BE REMOVED WITH THE DRIVING
PULLEY MOUNTED.
Specific tooling
020565Y Flywheel lock calliper spanner
ENG - 65
Engine
Inspecting the clutch drum
- Check that the clutch bell is not worn or damaged.
- Measure the inner diameter of the clutch bell.
Characteristic
Clutch bell diameter/standard value
Ø 107+0.2 +0 mm
Clutch bell diameter/max. value allowed after
use
Ø 107.5 mm
Eccentricity measured /max.
0.20 mm
Removing the clutch
- Equip the tool with long pins screwed into position
«A» from the outside, insert the entire driven pulley
in the tool and have the central screw make contact.
CAUTION
THE TOOL WILL BE DEFORMED IF THE CENTRAL SCREW
IS TIGHTENED UP TOO FAR.
- Using a 34 mm socket wrench remove the clutch
locking nut.
- Loosen the central screw by undoing spring of
the driven pulley unit
- Separate the components.
Specific tooling
020444Y Tool for fitting/ removing the driven
pulley clutch
ENG - 66
Vespa S 50 4T 4V (2008)
Vespa S 50 4T 4V (2008)
Engine
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 FAYING SURFACE AND MUST NOT BE DIFFERENT
FROM ONE ANOTHER.
VARIOUS CONDITIONS CAN CAUSE THE CLUTCH TO
TEAR.
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
- Remove the collar with the aid of 2 screwdrivers.
- Remove the three guide pins and the mobile half
pulley.
ENG - 67
Engine
Removing the driven half-pulley bearing
- Remove the roller bearing with the special extractor inserted from the bottom of the fixed halfpulley.
CAUTION
POSITION THE HOLDING EDGE OF THE EXTRACTION PLIERS BETWEEN THE END OF THE BEARING AND THE
BUILT IN SEALING RING.
Specific tooling
001467Y029 Bell for bearings, O.D. 38 mm
- Remove the ball bearing retention snap ring.
- Expel the ball bearing from the side of the clutch
housing by means of the special tool.
N.B.
PROPERLY SUPPORT THE HALF-PULLEY SO AS NOT TO
DEFORM THE SLIDING SURFACE OF THE DRIVING BELT
Specific tooling
020376Y Adaptor handle
020363Y 20-mm guide
Inspecting the driven fixed half-pulley
- Check that there are no signs of wear on the work
surface of the belt. If there are, replace the halfpulley..
- Make sure the bearings do not show signs of unusual wear.
- Measure the external diameter of the pulley bushing.
Characteristic
Stationary driven half-pulley/Standard diameter
Ø 33.965 to 33.985 mm
Stationary driven half-pulley / Minimum diameter admitted after use
Ø 33.96 mm
ENG - 68
Vespa S 50 4T 4V (2008)
Vespa S 50 4T 4V (2008)
Engine
Inspecting the driven sliding half-pulley
- Remove the 2 inner sealing rings and the two Orings.
- Measure the inside diameter of the mobile halfpulley bushing.
Characteristic
Mobile driven half-pulley/ Maximum diameter
allowed
Ø 34.08 mm
- Check the belt contact surfaces.
- Insert the new oil seal and O-rings on the mobile
half-pulley.
- Fitting the half-pulley on the bushing.
Recommended products
AGIP GREASE SM 2 Grease for the C-ring of
the tone wheel
Soap-based lithium grease containing NLGI 2 Molybdenum disulphide; ISO-L-XBCHB2, DIN
KF2K-20
- Make sure the pins and collar are not worn, reassemble the pins and collar.
- Use a greaser with a curved spout to lubricate the driven pulley unit with around 6 g of grease. This
operation must be done through one of the holes inside the bushing until grease comes out of the
opposite hole. This procedure is necessary to prevent the presence of grease beyond the O-ring.
Recommended products
AGIP GREASE SM 2 Grease for the C-ring of the tone wheel
Soap-based lithium grease containing NLGI 2 Molybdenum disulphide; ISO-L-XBCHB2, DIN KF2K-20
Refitting the driven half-pulley bearing
- Fit a new ball bearing with the specific tool.
- Fit the ball bearing retention snap ring.
- Fit the new roller bearing with the wording visible
from the outside.
CAUTION
PROPERLY SUPPORT THE HALF-PULLEY TO PREVENT
DAMAGE TO THE THREADED END WHILE THE BEARINGS
ARE BEING FITTED.
Specific tooling
020376Y Adaptor handle
ENG - 69
Engine
020456Y Ø 24 mm adaptor
020362Y 12 mm guide
020171Y Punch for Ø 17 mm roller case
Inspecting the clutch spring
- Check that the contrast spring of the driven pulley
does not show signs of deformation
- Measure the free length of the spring
Characteristic
Standard length
118 mm
Minimum length allowed after use
XXXX
- Check the thickness of the clutch mass friction
material.
-The masses must not show traces of lubricants;
otherwise, check the driven pulley unit.
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.
CAUTION
DO NOT OPEN THE MASSES USING TOOLS SO AS TO
PREVENT A VARIATION IN THE RETURN SPRING LOAD.
Characteristic
Minimum thickness permitted:
1 mm
Refitting the clutch
- Preassemble the driven pulley group with spring,
sheath and clutch.
- Position the spring with the sheath
- Insert the components in the tool and preload the
spring being careful not to damage the plastic
sheath and the end of the threaded bar.
ENG - 70
Vespa S 50 4T 4V (2008)
Vespa S 50 4T 4V (2008)
Engine
- Reassemble the nut securing the clutch and tighten to the prescribed torque.
CAUTION
SO AS NOT TO DAMAGE THE CLUTCH NUT USE A SOCKET WRENCH WITH SMALL CHAMFER.
CAUTION
POSITION THE NON-CHAMFERED SURFACES OF THE
NUT IN CONTACT WITH THE CLUTCH
Locking torques (N*m)
Nut locking clutch unit on pulley 55 ÷ 60 Nm
Refitting the driven pulley
-Refit the driven pulley assembly, the clutch bell
and the nut, using the specific tool.
Specific tooling
020565Y Flywheel lock calliper spanner
Locking torques (N*m)
Driven pulley shaft nut 40 to 44 Nm
Drive-belt
- Make sure the driving belt is not damaged and
does not have cracks in the toothed grooves.
- Check the width of the belt.
Characteristic
Transmission belt/Minimum width
17.5 mm
ENG - 71
Engine
Vespa S 50 4T 4V (2008)
Removing the driving pulley
- Lock the driving pulley using the appropriate tool.
- Remove the central nut with the related washer,
then remove the drive and the plastic fan.
- Remove the stationary half-pulley.
- Remove the belt, washer and remove the mobile half-pulley with its bushing, being careful that the
rollers and contrast plate fitted loosely on it do not come off.
Specific tooling
020451Y Starting ring gear lock
Inspecting the rollers case
1) Check that the bushing and the sliding rings of
the mobile pulley do not show signs of scoring or
deformation.
2) Check the roller running tracks on the contact
pulley; there must not be signs of wear and check
the condition of the contact surface of the belt on
the half-pulleys (mobile and stationary).
3) Check that the rollers do not show signs of
marked facetting on the sliding surface and that
the metallic insert does not come out of the plastic
shell borders.
4) Check the integrity of the sliding blocks of the
contact plate.
- Check that the internal bushing shown in the figure is not abnormally worn and measure inside
diameter «A».
- Measure outside diameter «B» of the pulley sliding bushing shown in the figure.
CAUTION
DO NOT LUBRICATE OR CLEAN THE BUSHING.
Characteristic
Driving pulley / Maximum diameter:
ENG - 72
Vespa S 50 4T 4V (2008)
Engine
20.12 mm
Driving pulley/ Standard diameter:
20.021 mm
Driving pulley bushing/ Diameter maximum:
XXX mm
Driving pulley bushing/ Standard diameter:
20 -0.020/-0.041mm
Refitting the driving pulley
- Manually move the movable driven half-pulley
away by pulling it towards the clutch unit and insert
the belt observing the direction of rotation of the
first fitting.
N.B.
IT IS GOOD PRACTICE ALWAYS TO FIT THE BELT SO
THAT THE WORDS CAN BE READ IN CASE IT DOES NOT
SHOW A FITTING SIDE.
- Refit the components of the assembly (roller container assembly with bushing, limiting washer, stationary half-pulley, cooling fan belt with drive,
washer and nut).
- With the specific tool, tighten the lock nut to 20
Nm and then perform a final 90° locking in order to
prevent the rotation of the driving pulley.
N.B.
REPLACE THE NUT WITH A NEW ONE AT EVERY REFIT
CAUTION
UPON FITTING THE DRIVING PULLEY UNIT IT IS OF UTMOST IMPORTANCE THAT THE BELT IS FREE INSIDE IN
ORDER TO AVOID WRONG TIGHTENING AND CONSEQUENTLY DAMAGING THE CRANKSHAFT KNURLING.
Specific tooling
020451Y Starting ring gear lock
Locking torques (N*m)
Crankshaft pulley nut 18 to 20 + 90° Nm
ENG - 73
Engine
Refitting the transmission cover
- Check the following for wear: toothed section,
toothed section shaft, cover seat bushing, pinion
shaft and its seating in the crankcase and the return spring.
- Remove the damaged components.
- Grease the spring.
- Remove the toothed sector and load the spring
with an appropriate tool.
- Refit the washer, the Seeger and the Kick-start
lever.
Recommended products
AGIP GREASE MU3 Grease for odometer
transmission gear case
Soap-based lithium grease with NLGI 3; ISO-LXBCHA3, DIN K3K-20
- Insert the pinion in its seating by pushing the starter lever.
- Fit the intake throat and tighten the 3 screws.
-Make sure the oil sump presents centring dowels
and sealing gaskets.
- Replace the cover tightening the 12 screws to the
prescribed torque.
-Refit the oil filling cap.
Locking torques (N*m)
Transmission cover screws 11 ÷ 13 Nm
End gear
ENG - 74
Vespa S 50 4T 4V (2008)
Vespa S 50 4T 4V (2008)
Engine
Removing the hub cover
• Remove the transmission cover
• Remove the clutch assembly
• Discharge the rear hub oil.
• Remove the 5 screws indicated in the figure.
• Remove the hub cover with driven pulley shaft.
See also
Refitting the clutch
Removing the wheel axle
- Remove the intermediate gear and the complete
gear wheel axle.
- When removing the intermediate gear pay attention to the various shim adjustments.
Removing the wheel axle bearings
- Remove the oil seal and the Seeger ring.
- Remove the bearing by pushing from the outside
towards the inside of the gear compartment, using
the appropriate punch.
Specific tooling
020363Y 20-mm guide
020376Y Adaptor handle
020358Y 37x40-mm Adaptor
ENG - 75
Engine
Removing the driven pulley shaft bearing
- Remove the Seeger ring inside the cover.
- Remove the oil seal from the outside.
- Remove the centring dowels and position the
cover on a plane.
- Position the special tool on the internal track of
the bearing and remove said bearing with the aid
of a press.
Specific tooling
020452Y Tube for removing and refitting the
driven pulley shaft
- Position the special tube on the internal raceway
of the bearing and from the shaft toothed side as
indicated in the figure. Expel the driven pulley shaft
with the aid of a press.
Specific tooling
020452Y Tube for removing and refitting the
driven pulley shaft
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.
- Check capacity ( A ) of the transmission gear
(wear, deformations, etc.)
- Check the pulley shaft seating: Superficial wear
( B ) may indicate irregularities in the crankcase
seatings or in the pulley shaft capacities
Inspecting the hub cover
- Check that the fitting surface is not dented or distorted.
- If faults are found, replace the hub cover.
ENG - 76
Vespa S 50 4T 4V (2008)
Vespa S 50 4T 4V (2008)
Engine
Refitting the driven pulley shaft bearing
- Support the inner track of the bearing from the
outside of the hub cover with the specific tool positioned under the press and insert the driven pulley
axle.
- Refit the oil seal flush with the cover.
Specific tooling
020452Y Tube for removing and refitting the
driven pulley shaft
• Heat the hub cover and insert the bearing with
the specific punch.
• Fit the snap ring with the concave or radial part
on the bearing side.
N.B.
FIT THE BALL BEARING WITH THE SHIELD FACING THE
OIL SEAL.
Specific tooling
020151Y Air heater
020376Y Adaptor handle
020439Y 17 mm guide
020358Y 37x40-mm Adaptor
Refitting the wheel axle bearing
- Heat the half crankcase on the transmission side
using a thermal gun.
- After lubricating its outer strip, insert the bearing
with the special adapter with the aid of a hammer.
- Refit the Seeger ring and the oil seal using the 42
x 47 mm adapter and the handle.
Specific tooling
020151Y Air heater
020376Y Adaptor handle
020363Y 20-mm guide
020359Y 42x47-mm Adaptor
ENG - 77
Engine
Refitting the ub cover
- Refit the whole wheel axle.
- Refit the intermediate gear paying attention to the
two shim washers.
- Apply LOCTITE 510 for surfaces to the hub covers and refit the same with driven pulley shaft.
- Refit the 5 screws and tighten them to the specified torque.
N.B.
CLEAN THE CONTACT SURFACES OF THE HUB COVER
AND THE HALF CRANKCASE OF RESIDUE FROM PREVIOUS GASKETS BEFORE APPLYING A NEW ONE.
Locking torques (N*m)
Locking torque: 11 to 13 Nm
Flywheel cover
Cooling hood
- Remove the manifold and the carburettor undoing the 2 fixing screws on the head
- Remove the fastening clamp of the secondary air
pipe and disconnect it
- Remove the 4 front coupling screws (1 of them is
a knob) and the side fixing screw at the crankcase
base.
- Remove the 4 side screws
- Extract the 3 covers - Remove the cover sealing
gaskets on the head
- For refitting, repeat the removal steps but in reverse order
CAUTION
TAKE CARE TO CORRECTLY POSITION THE FLYWHEEL
CONNECTOR.
N.B.
WHEN REFITTING THE COVER, TAKE CARE NOT TO DAMAGE THE STATOR WIRING.
ENG - 78
Vespa S 50 4T 4V (2008)
Vespa S 50 4T 4V (2008)
Engine
Cooling fan
- Remove the cooling fan by undoing the 3 screws
fixing it to the rotor
- When refitting the fan, pay attention that the
screw holes in the fan and the rotor coincide, then
tighten screws at the specified torque.
Removing the stator
- Remove the 2 Pick-Up screws and the 2 stator
fixing screws indicated in the figure.
- Remove the stator and its wiring.
ENG - 79
Engine
Refitting the stator
- Refit the stator and flywheel carrying out the removal procedure in reverse, tightening the retainers to the specified torque.
N.B.
THE PICK-UP CABLE MUST BE POSITIONED ADHERING
TO THE FUSION TONGUE ON THE CRANKSHAFT IN SUCH
A WAY AS TO AVOID BEING CRUSHED BY THE FAN COVER ASSEMBLY.
Locking torques (N*m)
Pick-up screws 3 ÷ 4 Stator screws 3 ÷ 4
Flywheel and starting
Removing the starter motor
- Undo the screw on the power positive contact
and disconnect the cable
- Undo the 2 screws fixing the starter motor to the
crankcase and recover the power wiring.
ENG - 80
Vespa S 50 4T 4V (2008)
Vespa S 50 4T 4V (2008)
Engine
Removing the flywheel magneto
- Lock the rotation of the flywheel using the calliper
spanner.
- Remove the nut.
CAUTION
THE USE OF A CALLIPER SPANNER OTHER THAN THE
ONE SUPPLIED COULD DAMAGE THE STATOR COILS
- Extract the flywheel with the extractor.
Specific tooling
020565Y Flywheel lock calliper spanner
020162Y Flywheel extractor
Inspecting the flywheel components
- Check that the flywheel internal magnets are in
good conditions.
- Check that the flywheel splines exhibit no loosening.
- Check there are no deformations that may cause
rubbing on the stator and the Pick-Up.
- Check that the stator winding, its ferromagnetic
support and the pick-up are in good conditions.
ENG - 81
Engine
Starter gear rim
- Check the toothing is level and in good conditions
Intermediate gear
- Check that the keying toothing on the crown and
the starter motor are in good conditions.
- Check that the Bendix opens and returns adequately.
Refitting the flywheel magneto
- Refit the stator and the pick-up being careful to
pass the wiring through the appropriate crankcase
couplings.
- Refit the flywheel to the crankshaft being careful
to respect the keying, then lock rotation with the
specific tool and tighten the nut to the prescribed
torque.
N.B.
A VARIATION OF THE AIR GAP DISTANCE CAN LEAD TO
A VARIATION IN THE IGNITION ADVANCE SUCH AS TO
CAUSE PINGING, KNOCKING ETC.
Specific tooling
020565Y Flywheel lock calliper spanner
Locking torques (N*m)
Flywheel nut 52 ÷ 58
ENG - 82
Vespa S 50 4T 4V (2008)
Vespa S 50 4T 4V (2008)
Engine
Refitting the starter motor
- Install the starter motor in its seating in the crankcase.
- Tighten the screw on the head side but do not
lock it, screw the second screw inserting the earth
cable (black), then tighten the 2 screws at the prescribed torque.
- Tighten the locking screw of the positive cable
(red) on the side contact.
N.B.
REFIT THE REMAINING PARTS AS DESCRIBED IN THE
CYLINDER HEAD, TIMING, LUBRICATION, FLYWHEEL
AND TRANSMISSION CHAPTERS.
Locking torques (N*m)
Starter screws 11 ÷ 13
Cylinder assy. and timing system
Removing the rocker-arms cover
- Remove the cooling covers
- Remove the 4 retainers of the tappet cover
- Remove the cover and the O-ring
- Remove the 3 screws and then remove the Blowby cover
- Clean the nozzle labyrinth and the membrane
(replace it, if necessary), then remove the cover
unit.
ENG - 83
Engine
Vespa S 50 4T 4V (2008)
Removing the timing system drive
- Temporarily loosen the tensioner central screw
and remove it together with the spring.
- Unscrew the 2 retainers indicated in the figure
and remove the chain tightener support being
careful to recover the sealing gasket.
N.B.
SHOULD THE GASKET NOT BE IN GOOD CONDITIONS,
REPLACE IT AFTER CAREFULLY CLEANING THE FAYING
SURFACE IN ORDER TO AVOID ENGINE OIL LEAKS
- Remove the driving pulley
- Remove the oil pump chain
- Remove the tappet cover
- Remove the central screw and the belleville
washer indicated in the figure and lock the camshaft crown with the specific tool.
N.B.
TO FACILITATE REMOVING THE HEAD COMPONENTS,
SET THE CRANKSHAFT TO THE TIMING POINT (TDC OF
THE COMPRESSION END).
Specific tooling
020565Y Flywheel lock calliper spanner
- Remove the camshaft control pulley and the washer below.
- Remove the pinion of the crankshaft timing control
- To remove the chain lower guiding pad, remove the head by pulling it upwards
N.B.
IT IS ADVISABLE TO MARK THE CHAIN IN ORDER TO ENSURE THAT THE DIRECTION OF ROTATION IS MAINTAINED.
See also
Removing the rocker-arms cover
Removal
Removing the driving pulley
ENG - 84
Vespa S 50 4T 4V (2008)
Engine
Removing the cam shaft
- Remove the limit screw of the rocking lever pins
shown in the figure.
- Remove the Seeger ring retaining the camshaft
bearing.
- Remove pins and rocking levers.
- Remove the calibrated pads
N.B.
MARK THE ASSEMBLY POSITION OF THE ROCKING LEVERS IN ORDER TO AVOID MISPLACING THE INTAKE AND
DISCHARGE ENDS.
- Remove the entire camshaft with bearing using
the specific tool shown in the figure.
- Take out the camshaft bearing with the aid of the
specific tool, being careful to mount a screw on the
camshaft in order to protect its thread.
N.B.
IF A BEARING SEPARATES FROM THE CAMSHAFT, IT IS
ESSENTIAL TO FIT A NEW BEAR.
Specific tooling
020450Y Camshaft fitting/removal tool
004499Y Camshaft bearing extractor
004499Y001 Bearing extractor bell
004499Y002 Bearing extractor screw
004499Y006 Bearing extractor ring
004499Y027 Bearing extractor part
ENG - 85
Engine
Removing the cylinder head
- Remove the cooling covers, the timing control,
the camshaft and the rocking levers.
- 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.
IF NEEDED, THE HEAD MAY BE REMOVED WITH THE
CAMSHAFT, PINS AND ROCKING LEVERS WITHOUT REMOVING THE DRIVING PULLEY UNIT. REMEMBER TO
HOLD THE TIMING CHAIN WITH A PIECE OF METAL CABLE AND TO ADJUST THE CHAIN TIGHTENER UPON REFITTING.
Removing the valves
- Using the specific tool fitted with the part shown
in the figure, remove cotters, caps and valve
springs.
- Remove the oil seals with the appropriate tool.
Specific tooling
020431Y Valve oil seal extractor
020382Y Valve cotters equipped with part 012
removal tool
ENG - 86
Vespa S 50 4T 4V (2008)
Vespa S 50 4T 4V (2008)
Engine
Removing the cylinder - piston assy.
- Remove the cylinder paying attention to the 2
cylinder centring dowels in the housing.
- Remove the cylinder base gasket.
To avoid damaging the piston, keep it fixed while
removing the cylinder.
- Remove the two stop rings, the wrist pin and the
piston.
- Remove the 3 piston rings.
N.B.
BE CAREFUL NOT TO DAMAGE THE PISTON RINGS DURING REMOVAL.
Inspecting the small end
- Measure the internal diameter of the small end
using an internal micrometer.
N.B.
IF THE DIAMETER OF THE ROD SMALL END EXCEEDS
THE MAXIMUM DIAMETER ALLOWED, SHOWS SIGNS OF
WEAR OR OVERHEATING REPLACE THE CRANKSHAFT
AS DESCRIBED IN THE "CRANKCASE AND CRANKSHAFT" CHAPTER".
Characteristic
Max. diameter admitted: check the small end
13.030 mm
Standard diameter: check the small end
13 +0.025+0.015mm
ENG - 87
Engine
Inspecting the wrist pin
- Measure the outer diameter of the gudgeon pin.
Characteristic
Standard diameter: gudgeon pin
13 -0-0.004mm
Minimum admissible diameter gudgeon pin
12.990 mm
Inspecting the piston
- Measure the diameter of the bearings on the piston.
Characteristic
Pin seat diameter
13 +0.005 +0.010 mm
- Carefully clean the seal housings.
- Measure the coupling clearance between the
sealing 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.
N.B.
MEASURE THE CLEARANCE BY INSERTING THE BLADE
OF THE FEELER THICKNESS GAUGE FROM THE SECOND
SEAL SIDE.
Fitting clearance
Top piston ring - standard coupling clearance
0.03 ÷ 0.065 mm Top piston ring - maximum clearance allowed after use 0.07 mm Middle piston
ring - standard coupling clearance 0.02 ÷ 0.055
mm Middle piston ring - maximum clearance allowed after use 0.06 mm oil scraper ring - standard coupling clearance 0.04 ÷ 0.16 mm oil scraper
ring - maximum clearance allowed after use
0.17 mm
ENG - 88
Vespa S 50 4T 4V (2008)
Vespa S 50 4T 4V (2008)
Engine
Inspecting the cylinder
- Using a bore meter, measure the inner cylinder
diameter at three different points according to the
directions shown in the figure.
- Check that the coupling surface with the head is
not worn or misshapen.
- 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).
Characteristic
Maximum allowable run-out:
0.05 mm
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 thickness 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.
ENG - 89
Vespa S 50 4T 4V (2008)
Engine
SEAL RINGS
Name
1st Compression ring
2nd Compression ring
Oil scraper ring
1st Compression ring
1st Oversize
2nd Compression ring
1st Oversize
Oil scraper ring 1st
Oversize
1st Compression ring
2nd Oversize
2nd Compression ring
2nd Oversize
Oil scraper ring 2nd
Oversize
1st Compression ring
3rd Oversize
2nd Compression ring
3rd Oversize
Oil scraper ring 3rd
Oversize
Description
Dimensions
39 x 1
39 x 1
39 x 2
39.2 x 1
Initials
A
A
A
A
Quantity
0.08 ÷ 0.20
0.05 ÷ 0.20
0.20 ÷ 0.70
0.08 ÷ 0.20
39.2 x 1
A
0.05 ÷ 0.20
39.2 x 2
A
0.20 ÷ 0.70
39.4 x 1
A
0.08 ÷ 0.20
39.4 x 1
A
0.05 ÷ 0.20
39.4 x 2
A
0.20 ÷ 0.70
39.6 x 1
A
0.08 ÷ 0.20
39.6 x 1
A
0.05 ÷ 0.20
39.6 x 2
A
0.20 ÷ 0.70
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.
Specific tooling
020448Y Pin lock fitting tool
ENG - 90
Vespa S 50 4T 4V (2008)
Engine
- With the opening in the position indicated on the
tool, set the lock ring into position in the tool with
the punch.
- Rest the tool on the piston paying attention that
the 90°chamfered side faces upwards as indicated
in the figure.
- Fit the gudgeon pin stop using the plug.
CAUTION
USING A HAMMER TO POSITION THE RINGS CAN DAMAGE THE LOCKING HOUSING.
Refitting the piston rings
- Fit the oil scraper ring starting from the spring,
taking care that the spring ends do not superimpose. Fit the two piston rings so that their gaps and
that of the oil scraper ring are never aligned.
- Fit the 2nd sealing ring with the identifying letter
«T» facing towards the piston crown.
- Fit the 1st sealing ring with the reference letter
«T» facing towards the piston crown.
- Misalign the lining openings at 120° as shown in
the figure.
- Lubricate the components with engine oil.
N.B.
IN ORDER TO OBTAIN A GOOD BEDDING, THE 2 SEALING
PISTON RINGS ARE MADE OF CONE SHAPED CONTACT
SECTION TO THE CYLINDER. AS A RESULT IT IS IMPORTANT TO RESPECT THE FITTING INSTRUCTION TO ASSEMBLY THE RINGS WITH THE "T" MARK FACING
UPWARDS.
ENG - 91
Engine
Vespa S 50 4T 4V (2008)
Refitting the cylinder
- Insert the cylinder base gasket.
- Fit the cylinder as shown in the figure.
- The piston can be kept out of the housing plane
using the appropriate tool.
N.B.
BEFORE FITTING THE CYLINDER, CAREFULLY BLOW
OUT THE LUBRICATION DUCT AND OIL THE CYLINDER
BARREL.
Specific tooling
020288Y Fork to assemble piston on cylinder
If the four cylinder stud bolts should be replaced in this kind of engine, it is necessary to tighten the
head nuts strictly following the procedure below.
The procedure is different from that indicated in the vehicle manuals:
Head tightening nut (only to replace stud bolts) 6÷7 N*m + 135° + 90°
The 45° rotation reduction of the key is necessary to avoid stud bolt stretching.
Inspecting the cylinder head
- Using a trued bar check that the cylinder head
surface is not worn or distorted.
- Check that the camshaft and rocking lever pin
bearings show no signs of wear.
- Check that the cylinder head cover surface, the
intake manifold and the exhaust manifold are not
worn.
- It is advisable to replace the head if any failure is
found.
Characteristic
Maximum allowable run-out:
0.1 mm
ENG - 92
Vespa S 50 4T 4V (2008)
Engine
Measure the camshaft bearing seats and rocking
lever support pins with a bore meter
HEAD CHECK
Specification
Standard diameter (mm) A
Standard diameter (mm) B
Standard diameter (mm) C
Desc./Quantity
Ø 32.015 ÷ 32.025 mm
Ø 16.0 ÷ 16.018
Ø 11.0 ÷ 11.018
Inspecting the timing system components
- Check that the guide shoe and the tensioner shoe
are not worn out.
- Ensure that the camshaft drive pulley, the chain
assembly and the sprocket wheel are not worn.
- If sings of wear are found, replace the parts. if the
chain, pinion or pulley are worn, replace the whole
assembly.
- Remove the central screw 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.
ENG - 93
Vespa S 50 4T 4V (2008)
Engine
Inspecting the valve sealings
- Clean the valve seats of any carbon residues.
- Using the Prussian blue, check the width of the
impression on the valve seat "V".
Characteristic
Standard value:
1 - 1.3 mm
Admissible limit:
1.6 mm
- If the impression width on the valve seat is larger than the prescribed limits, true the seats with a 45°
mill and then grind.
- In case of excessive wear or damages, replace the head.
- 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.
Inspecting the valves
STANDARD VALVE LENGTH
Specification
Inlet: standard length
Outlet: standard length
ENG - 94
Desc./Quantity
74.9 mm
74.35 mm
Vespa S 50 4T 4V (2008)
Engine
- Measure the diameter of the valve stems in the
three positions indicated in the diagram.
STANDARD DIAMETER
Specification
Inlet
drainage
Desc./Quantity
3.970 ÷ 3.985 mm
3.960 ÷ 3.975 mm
MINIMUM DIAMETER PERMITTED
Specification
Inlet
drainage
Desc./Quantity
3.958 mm
3.945 mm
- Calculate the clearance between valve and valve guide.
- Check the concentricity of the valve head by arranging a dial gauge at right angle relative to the
valve head and rotate it on a "V" shaped abutment.
Characteristic
Admissible limit:
0.03 mm
- Check the deviation of the valve stem by resting
it on a «V» shaped abutment and measuring the
extent of the deformation with a dial gauge.
Characteristic
Limit values admitted:
0.1 mm
ENG - 95
Vespa S 50 4T 4V (2008)
Engine
Inspecting the valve stem guide clearance
Measure the valve guides
VALVE GUIDE DIAMETER
Specification
Valve guide
Valve guide
Desc./Quantity
Standard diameter: 4 + 0.012 mm
Maximum admissible diameter: 4 + 0.022 mm
- After measuring the valve guide diameter and the
valve stem diameter, check clearance between
guide and stem.
INLET
Specification
Standard clearance
Admissible limit
Desc./Quantity
0.015 ÷ 0.042 mm
0.06 mm
OUTLET
Specification
Standard clearance
Admissible limit
ENG - 96
Desc./Quantity
0.025 ÷ 0.052 mm
0.07 mm
Vespa S 50 4T 4V (2008)
Engine
Refitting the valves
- Lubricate the valve guides with graphite grease.
- Place the lower caps of the valve spring on the
head.
- Use the punch to fit the 4 sealing rings one at a
time.
- Fit the valves, the springs and the upper caps.
- Using the appropriate tool, compress the springs
and insert the cotters in their seats.
Inspecting the cam shaft
- Inspect the cam shaft for signs of abnormal wear
on the cams.
Characteristic
Standard diameter - Bearing A:
Ø 12 +0.002 +0.010
mm Standard
diameter - Bearing B:
Ø 16-0.015 -0.023 mm
Minimum diameter allowed - Bearing A:
Ø 11.98 mm
Minimum diameter allowed - Bearing B:
Ø 15.96 mm
-Using a gauge, measure the cam height.
Check the axial clearance of the camshaft
ENG - 97
Vespa S 50 4T 4V (2008)
Engine
- 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.
N.B.
A BALL BEARING IS FITTED ON BEARING «A»; CONSEQUENTLY, BEARING «B» IS THE MOST IMPORTANT AS IT
WORKS DIRECTLY ON THE HEAD ALUMINIUM
Characteristic
Standard height - Inlet
24.397 mm
Standard height - Outlet
23.996 mm
Fitting clearance
Maximum admissible axial clearance: 0.5 mm
- Measure the outside diameter of the rocking lever pins
- Check the rocker pins do not show signs of wear or scoring.
- Measure the internal diameter of each rocking lever.
- Check that the pad in contact with the cam is not worn.
ROCKING LEVERS AND PIN DIAMETER:
Specification
Rocking levers - Inside diameter
Rocking levers - Pins diameter
Desc./Quantity
11.015 ÷ 11.035 mm
10.977 ÷ 10.985 mm
Refitting the head and timing system components
- Fix the head on a workbench.
- Screw the tool to fit the camshaft fully down on the bearing's inner track.
- Fit the camshaft fully into its seating together with the bearing with the aid of a mallet.
- Remove the tool.
- Fit the head gasket after cleaning the faying surface carefully.
ENG - 98
Vespa S 50 4T 4V (2008)
Engine
- Insert the head in the cylinder stud bolts and tighten the 4 fixing nuts to the prescribed torque.
Specific tooling
020450Y Camshaft fitting/removal tool
- Fit pins, inlet rocking lever and discharge rocking
lever.
- Lubricate the 2 rocking levers through the holes.
N.B.
IF A BEARING SEPARATES FROM THE CAMSHAFT, IT IS
ESSENTIAL TO FIT A NEW BEARING.
- Screw up the limit screw of the rocking lever pins
and tighten it to the prescribed torque.
- Reposition the Seeger ring retaining the camshaft
Locking torques (N*m)
Rocking lever shafts screw 3 ÷ 4
- Finish the head tightening following the procedure below: screw the four head nuts to an initial
torque at two crossed passes. Afterwards tighten
the nuts with 2 turns of 90° each to be done at two
crossed passes.
-Finish the tightening of the head to the crankcase
with the 2 side screws.
N.B.
SHOULD THE CRANKCASE OR THE CYLINDER STUD
BOLTS BE REPLACED, IT IS NECESSARY TO CARRY OUT
AN INITIAL TIGHTENING PLUS OTHER 3 TURNS OF 90°
EACH AT 3 CROSSED PASSES
Locking torques (N*m)
Head-cylinder stud bolt nuts: 6 ÷ 7 +135° +90° Nm
first fitting, upon refitting tighten again at 6 ÷ 7 90° +90°
Nm Head cover screws 8 ÷ 10 Nm
ENG - 99
Engine
Refitting the timing chain
- Insert the timing chain pads in their corresponding seatings, the screw and the spacer as indicated in the figure.
- Tighten to the prescribed torque and check the
tensioner pad moves adequately.
- Insert the timing pinion in driving shaft with the
chamfered side facing the insertion (towards the
main bearing).
- Loop the timing chain around the sprocket on the
crankshaft.
Locking torques (N*m)
Chain tensioner pad screw 5 ÷ 7 Nm
- Refit 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.
- With this operation, insert the chain on the camshaft control pulley and make the reference notch
coincide with the point on the head.
- Fit the pulley onto the camshaft.
- Fit the belleville washer so that the outer rim
touches the pulley.
- Bring the screw closer but without reaching its
final locking point.
- Push the tensioner pad lightly so as to check the
correct timing.
- Use the specific tool to lock the camshaft crown
gear and tighten the screw.
- Adjust valve clearance.
- Replace the O-Ring on the tappet cover.
- Fit the tappet cover and lock it with the 4 fixing
screws indicated in the figure.
Specific tooling
020565Y Flywheel lock calliper spanner
Locking torques (N*m)
ENG - 100
Vespa S 50 4T 4V (2008)
Vespa S 50 4T 4V (2008)
Engine
Camshaft pulley screw 12 ÷ 14 Head cover
screw 8 ÷ 10 Nm
- Set the tensioner cursor in 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 spring with the central screw and tighten it to the prescribed torque.
- Fit the spark plug.
Electric characteristic
Distanza elettrodi:
0,6 mm
Candela
NGK ER9EH-6N
Locking torques (N*m)
Timing chain tensioner screw 8 ÷ 10 Nm Timing chain tensioner central screw 5 - 6 Ignition spark
plug 10 ÷ 15 Nm
Refitting the rocker-arms cover
- Carry out the removal procedure but in reverse
order and tighten the four fixing screws to the
specified torque.
N.B.
FIT A NEW O-RING ON THE TAPPET COVER.
Refitting the intake manifold
-Fit the cover sealing gaskets on the head.
-Fit the 2 covers.
- Fit the inlet manifold and do up the 2 screws to
the specified torque.
-Fit the carburettor on the inlet manifold and lock
the clamp.
-Fit the secondary air pipe and fix it with the appropriate clamp.
N.B.
FIT THE CARBURETTOR THROUGH THE SUPPLEMENT
ON THE MANIFOLD.
ENG - 101
Engine
Vespa S 50 4T 4V (2008)
Locking torques (N*m)
Inlet manifold screw 7 ÷ 9 Nm
Crankcase - crankshaft
- First remove the following units:
Driving pulley Driven pulley
Final reduction greasing
Oil pump Flywheel with stator
Cylinder-piston-head unit
Starter motor with cables.
See also
Removing the driving pulley
Removal
Removing the driven pulley
Removing the cylinder - piston assy.
Removing the starter motor
Removing the stator
Splitting the crankcase halves
- Remove the ten crankshaft coupling screws.
-Separate the crankcase halves keeping the half
casing driving shaft engaged on the transmission
side.
- Remove the crankshaft.
CAUTION
IF YOU FAIL TO DO THIS, THE CRANKSHAFT MIGHT ACCIDENTALLY FALL.
- Remove the oil guard on the flywheel side.
CAUTION
THE CENTRIFUGAL OIL FILTER IS IN THE FLYWHEEL AXLE SHAFT. CONSEQUENTLY, DO NOT
WASH WITH SOLVENTS OR BLOW COMPRESSED AIR SO THAT NO IMPURITIES LEAK OUT. A
CENTRIFUGAL OIL FILTER'S LIFE IS THE SAME AS THE ENGINE'S AND IS MAINTENANCE
FREE.
ENG - 102
Vespa S 50 4T 4V (2008)
Engine
- Check the axial clearance on the connecting rod.
Fitting clearance
Standard connecting rod axial clearance 0.15 ÷
0.30 mm Max. connecting rod clearance 0.5 mm
- Check the correct radial clearance of the connecting rod by holding the driving shaft with your
hands and, with a dial gauge fitted to the rod small
end, measuring the clearance, move the connecting rod vertically as shown in the figure.
Fitting clearance
Connecting rod radial - standard clearance
0.006 ÷ 0.018 mm Connecting rod max. - radial
clearance 0.25 mm
- Check that the half shaft surfaces are not scored
and with the aid of a gauge check the driving shaft
width as indicated in the figure.
Characteristic
Standard measure
45 mm
Removing the crankshaft bearings
- Remove the flywheel bearing fitted on the driving
shaft using the specific tool.
Specific tooling
004499Y Camshaft bearing extractor
004499Y001 Bearing extractor bell
004499Y002 Bearing extractor screw
004499Y006 Bearing extractor ring
004499Y034 Bearing extractor part
ENG - 103
Engine
Refitting the crankshaft bearings
- Support the crankcase on a surface and place it
with the driving shaft axle in a vertical position.
- Warm the crankcase at ~ 120° C with a thermal
gun (and support).
- Fit the punch with guide and adaptor, place the
bearing on the punch using grease (to keep it from
falling).
-Insert the bearing in the crankcase; if needed, use
a mallet but do so with extreme care so as not to
damage the engine crankcase limit stop.
Specific tooling
020359Y 42x47-mm Adaptor
020364Y 25-mm guide
020376Y Adaptor handle
020360Y 52x55-mm Adaptor
- Heat a new main bearing in an oil bath at 120°.
- Place the driving shaft on the support base and
insert the bearing with the aid of an adequate piece
of tube if necessary.
N.B.
USE A NEW BEARING WHEN REFITTING
WARNING
THE CENTRIFUGAL OIL FILTER IS IN THE FLYWHEEL
AXLE SHAFT. DO NOT WASH WITH SOLVENTS OR BLOW
COMPRESSED AIR SO THAT NO IMPURITIES LEAK OUT.
Specific tooling
020265Y Bearing fitting base
008119Y009 Tube to assemble shafts and
axles
ENG - 104
Vespa S 50 4T 4V (2008)
Vespa S 50 4T 4V (2008)
Engine
Inspecting the crankshaft alignment
- Install the crankshaft on the support and measure
the displacement at the 4 points shown in the figure.
N.B.
IF VALUES OTHER THAN THOSE ALLOWED ARE DETECTED, TRY STRAIGHTENING THE CRANKSHAFT BY INSERTING A WOODEN WEDGE BETWEEN THE HALF
SHAFTS OR BY CLOSING THEM WITH A VICE AS NEEDED. IF EVEN AFTER THIS OPERATION THE VALUES ARE
NOT THOSE ADMITTED, REPLACE THE CRANKSHAFT.
Characteristic
Off-line maximum admitted - A
0.15 mm
Off-line maximum admitted - B
0.02 mm
Off-line maximum admitted - C
0.02 mm
Off-line maximum admitted - D
0.10 mm
- 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.
Specific tooling
020074Y Support base for checking crankshaft alignment
Refitting the crankcase halves
-Be careful to place the two centring dowels preferably on the flywheel side half casing.
-Insert the crankshaft on the half casing on the
transmission side.
ENG - 105
Engine
- Fit the gasket recommended for surfaces on the
half casing on the transmission side after greasing
the two faying surfaces carefully.
-Insert the flywheel half casing.
- Fit the 10 screws and tighten them to the prescribed torque.
N.B.
WHEN FITTING THE HALF CASING AND THE CRANKSHAFT, TAKE CARE NO TO DAMAGE THE SHAFT THREADED TANGS.
Recommended products
Loctite 510 Liquid sealant
Gasket
Locking torques (N*m)
Half casing joint bolts: 8 ÷ 10 Nm
- Fit a new O-Ring on the mesh oil filter and on the
filling cap; lubricate the rings.
- Insert the filter on the engine and lock the cap to
the prescribed torque.
Locking torques (N*m)
Engine oil pre-filter cover: 25 ÷ 28 Nm
Lubrication
Crankshaft oil seals
Removal
- Extract the flywheel oil seal from the crankcase
being careful not to damage or score the crankcase.
ENG - 106
Vespa S 50 4T 4V (2008)
Vespa S 50 4T 4V (2008)
Engine
- Check that the chain contrast pad is not worn.
-Otherwise, replace the pad or fit it inverted to
make it work on the other side.
- Any operation on the chain cover oil seal should
be carried out placing the cover on the workbench
on the covering plate side of the oil pump chain.
-Remove the oil seal with a tube section of 30 mm
in diameter (Ø 32 mm Max).
Refitting
- Apply engine oil on the oil seal and it seating on
the crankcase.
- From the outside and using the specific punch,
place the oil seal fully down until it reaches the
bottom of the seating in the crankcase.
N.B.
FAILURE TO USE THE SPECIFIC TOOL CAN RESULT IN
AN INCORRECT DEPTH POSITION AND AS A CONSEQUENCE IN INADEQUATE OIL SEALING.
- Fit a new oil seal on the outer rim with the help of
the specific tools below.
- Fit a new O-ring and lubricate it with grease.
- Install the cover on the engine crankcase, insert
the three screws and place the cover in its position.
- Tighten the 3 screws to the prescribed torque.
Specific tooling
020376Y Adaptor handle
020358Y 37x40-mm Adaptor
Locking torques (N*m)
Timing chain/oil pump compartment cover
screws 4 ÷ 5 Nm
Oil pump
ENG - 107
Engine
Removal
- Remove the chain compartment cover undoing
the 3 fixing screws indicated in the figure.
- Take out the cover using the appropriate fusion
couplings on the cover with a pair of pliers
- Undo the 2 clamping screws in the figure and remove the cover over the pump control crown gear.
- Block the rotation of the oil pump control gear with
a screwdriver inserted through one of its pump
holes.
- Remove the central screw and the belleville
washer
- Remove the chain with the crown gear.
- Remove the crankshaft control pinion.
- Remove the oil pump by undoing the 2 screws
indicated in the figure.
- Remove the oil pump seal.
IT IS ADVISABLE TO MARK THE CHAIN IN ORDER TO ENSURE THAT THE INITIAL DIRECTION OF ROTATION IS
MAINTAINED.
Inspection
- Remove the two screws and the oil pump cover.
- Remove the clip retaining the innermost rotor.
- Remove and wash the rotors thoroughly with a
degreasing solvent and compressed air.
- Reassemble the rotors in the pump body, keeping the two reference marks visible Replace the
clip.
ENG - 108
Vespa S 50 4T 4V (2008)
Vespa S 50 4T 4V (2008)
Engine
- Measure distance between rotors (inner rotor/
outer rotor) with a thickness gauge in the position
shown in the picture.
Characteristic
Admissible maximum clearance 1
0.15 mm
Measure the distance between the outer rotor and
the pump body (see figure).
Characteristic
Admissible maximum clearance 2
0.20 mm
- Check the axial clearance of the rotors using a
trued bar as reference as shown in the figure.
N.B.
MAKE SURE THE TRUED BAR IS POSITIONED PROPERLY
ON THE TWO POINTS ON THE PUMP BODY.
Characteristic
Admissible maximum clearance 3
0.09 mm
Refitting
- 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 assembly.
- Fit the cover on the pump being careful to align
the holes (2 on the cover and 2 on the pump body)
fixing the oil pump on the crankcase.
- Fit the oil pump on the crankcase by tightening
the two screws to the prescribed torque.
ENG - 109
Engine
- Fit the pulley on the pump, the central screw to
the specified torque and the belleville washer.
- Check that there is no seizing and/or friction during the pulley rotation.
N.B.
FIT THE BELLEVILLE WASHER SO THAT ITS OUTER
(CURVED) RIM TOUCHES THE PULLEY.
Locking torques (N*m)
Central screw 12 ÷ 14 Nm Cover screws 0.7 ÷ 0.9
Nm Oil pump screws 5 - 6
Removing the oil sump
- Remove the oil filling cap, the transmission cover,
the complete driving pulley assembly with belt and
pinion.
- Unscrew the oil drainage plug «A» shown in the
figure and drain out all the oil from the sump.
- Remove the 6 screws indicated in the figure.
Refitting the oil sump
- Clean and grease the faying surfaces.
- Apply LOCTITE 510 on the sump surface and
tighten the 6 fixing screws to the specified torque.
- Refit the driving pulley assembly, the belt, the
pinion and the transmission cover.
WHEN TESTING THE LUBRICATION SYSTEM, REFER TO
THE "CRANKCASE AND CRANKSHAFT" CHAPTER, REGARDING LUBRICATION OF THE CRANKSHAFT AND
CONNECTING ROD
Locking torques (N*m)
Oil sump screws 8 ÷ 10 Nm
ENG - 110
Vespa S 50 4T 4V (2008)
Vespa S 50 4T 4V (2008)
Engine
Fuel supply
- Disconnect the fuel supply and the suction taking
pipe from the carburettor.
- Check that there are no fuel leaks between the
two tubes.
- Close the fuel outlet pipe.
- By means of the MITYVAC pump apply 0.1 bar
of suction to the tap.
- Make sure that the suction is kept stable and that
and that there are no fuel leaks.
- Reconnect the suction pipe to the manifold.
- Position the fuel pipe with the outlet at the point
of the tap.
- Turn the engine by using the starter for five seconds with the carburettor at minimum.
- Take up the fuel by means of a graded burette.
N.B.
THE MEASUREMENT MAY BE FALSIFIED BY THE INCORRECT NUMBER OF REVS OR BY THE WRONG POSITION
OF THE TUBE. IN THIS CASE, THE TENDENCY IS TO OBTAIN A REDUCED FUEL FLOW RATE. THE SUCTION OUTLET ON THE MANIFOLD HAS A SECTION INTENTIONALLY
REDUCED FOR THE PURPOSE OF ENHANCING THE SUCTION PULSATION AND THEREBY GUARANTEE A CONSTANT TAP FLOW RATE.
Specific tooling
020329Y MityVac vacuum-operated pump
Characteristic
Minimum flow rate
20 cc
- Completely empty the fuel tank.
- Remove the petrol delivery pipe and the lowpressure pipe.
- Loosen the clip and remove the cock.
- Clean the tank and the filter of the cock with a
specific solvent.
- Refit the cock making sure that there is an ORing.
- Turn the cock to the direction it had before it was
removed and block the clip.
ENG - 111
Engine
N.B.
THE FILTER CAN BE UNSCREWED FROM THE COCK TO
FACILITATE CLEANING.
Removing the carburettor
- To detach the carburettor from the engine, remove the two clamps anchoring the carburettor to
the inlet manifold and the air intake coupling to the
filter.
- Remove the fuel supply pipe.
- Disconnect the starter connection.
- Detach the accelerator cable with the sheath that
connects the plate and the support.
- Remove the carburettor.
- Remove the protection, the bracket and the starter undoing the screw shown in the figure.
CAUTION
THE CARBURETTOR FEATURES AN ANTI-VIBRATION
RUBBER BUFFER FITTED ON THE LOWER SUPPLEMENT
OF THE ACCELERATING PUMP BODY. UPON REFITTING
THE CARBURETTOR ON THE ENGINE, MAKE SURE THIS
BUFFER IS PRESENT SO THAT THE PETROL IN THE TANK
DOES NOT EMULSIFY.
- Remove the 2 fixing screws indicated in the figure, the vacuum chamber cover and the spring.
- Remove the vacuum valve together with the diaphragm; the pin, the spring and its plastic guide.
WARNING
DURING THE REMOVAL OF THE COVER TAKE SPECIAL
CARE NOT TO RELEASE THE SPRING ACCIDENTALLY.
- Remove the 3 fixing screws and the chamber with
the gasket.
ENG - 112
Vespa S 50 4T 4V (2008)
Vespa S 50 4T 4V (2008)
Engine
- Remove the chamber components following the
procedure below.
- Undo the 2 screws fixing the intake pump diaphragm cover.
- Remove the cover being careful with the spring
below, then remove the spring, take out the rubber
protection and the diaphragm together with the
pipe O-Ring.
-Remove the accelerating pump jet together with
the ball spring.
- Remove the screw indicated in the figure fixing
the float pin.
- Remove the float and the plunger.
-Remove the maximum nozzle.
-Remove diffuser.
ENG - 113
Engine
Vespa S 50 4T 4V (2008)
-Remove the minimum nozzle.
- Remove the sprayer tilting the carburettor body.
N.B.
THIS OPERATION IS NECESSARY TO AVOID LOSING
SPRAYER PARTS WHEN CLEANING THE CARBURETTOR
BODY. IF THE SPRAYER IS FORCED IN ITS HOUSING DO
NOT ATTEMPT TO REMOVE IT AS THIS WILL ONLY DAMAGE IT.
- Remove the idle flow screw with the O-ring and
the spring.
CAUTION
DO NOT ATTEMPT REMOVING PARTS EMBEDDED IN THE CARBURETTOR BODY SUCH AS:
FUEL SUPPLY PIPE, PIN SEATING, STARTER NOZZLE, THROTTLE VALVE CONTROL VALVE
SHAFT. DO NOT REMOVE THROTTLE-SHAFT CONNECTION SCREWS. THE FIXING SCREWS
ARE CAULKED AFTER THE ASSEMBLY AND THEIR REMOVAL DAMAGES THE SHAFT.
ENG - 114
Vespa S 50 4T 4V (2008)
Engine
Refitting the carburettor
- Before refitting, wash the carburettor body accurately with a degreasing solvent and compressed
air.
- Pay special attention to the fuel supply pipe and
the plunger seat.
- 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.
The acceleration nozzle outlet is extremely small
and is oriented to the throttle valve.
- Check that the carburettor body has the closing ball for the idle circuit pipe.
- Check that the coupling surfaces, the chamber 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.
N.B.
TO AVOID DAMAGES, DO NOT INTRODUCE METAL OBJECTS IN THE ADJUSTED SECTIONS.
ENG - 115
Engine
- Wash and blow the minimum nozzle properly and
reassemble it.
- Accurately wash and blow the components of the
maximum circuit, the sprayer, the diffuser and the
nozzle.
- Introduce the sprayer in the carburettor body with
the bigger cylindric part directed to the diffuser.
- Fit the diffuser.
-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 rod and that there
are no fuel infiltrations.
- Replace it in case of anomalies.
- Fit the float together with the pin and rod in its
position and lock it with its screw.
N.B.
INTRODUCE THE RETURN SPRING ON THE FLOAT
PLATE ADEQUATELY
- Insert the ball in the corresponding accelerating
pump.
- Fit the spring.
- Fit the accelerating pump nozzle.
WARNING
WHEN REFITTING, PAY SPECIAL ATTENTION TO THE
COMPONENTS AS THEY ARE SMALL.
ENG - 116
Vespa S 50 4T 4V (2008)
Vespa S 50 4T 4V (2008)
Engine
- Check the diaphragm is in good conditions and
remove the remaining components of the accelerating pump following these steps:
- Insert the O-Ring in the pipe.
- Insert the diaphragm together with the pin and its
spring.
N.B.
REPLACE THE DIAPHRAGM IF THERE ARE SIGNS OF UNDULATIONS, CRACKS OR HARDENING.
- Fit the accelerating pump diaphragm cover and
tighten the 2 fixing screws making sure the spring
below is correctly positioned.
- Fit the rubber bellows protecting the pin in the
upper part of the accelerating pump.
Level check
- Tilt the carburettor so that the needle valve at the
fuel supply is closed and the float weight does not
affect it.
- Check that the diaphragm closing line and the
float central line are parallel as shown in the figure.
- Blow air in to the tank and then assembly it and
its gasket on the carburettor body with the 3 fixing
screws.
N.B.
-ALWAYS USE NEW RINGS AND GASKETS FOR REFITTING.
WARNING
THE SCREW IN THE TANK BOTTOM IS A BLEEDING ONE
AND CONSEQUENTLY IT ONLY REQUIRES CLEANING.
ENG - 117
Engine
- Insert the diaphragm into the throttle valve.
- Insert the tapered pin together with the plastic
support and the contrast spring into the throttle
valve.
N.B.
PLACE THE SPRING PLASTIC SUPPORT WITH ITS TEETH
FACING THE INNER SIDE OF THE MEMBRANE TO BE
ABLE TO FIT THE LOWER END OF THE THROTTLE VALVE
SPRING.
- Fit the vacuum chamber cover with the 2 fixing
screws paying special attention to the spring.
Inspecting the automatic choke device
- Check that the automatic starter piston is not deformed or rusty.
- Check that the piston slides freely in its seating.
- Check that the piston sealing O-Ring 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.
Characteristic
Protrusion value
11.5 mm
ambient temperature
24° C
ENG - 118
Vespa S 50 4T 4V (2008)
Vespa S 50 4T 4V (2008)
Engine
- The starter should disconnect progressively by
means of electric heating.
- Check the starter resistance when adjusted to the
ambient temperature.
Characteristic
ambient temperature
24° C
Electric characteristic
Automatic starter resistance
20 Ω ± 5 %
- Use battery to power the automatic starter and
check that 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.
Characteristic
Battery
12V-9Ah
max. protrusion
15 mm
max. time
15 min
- Fit the starter, the support bracket and the protection with the screw indicated in the figure.
ENG - 119
Engine
Vespa S 50 4T 4V (2008)
- Insert rubber pipes for chamber ventilation.
- Insert the O-Ring, the washer, the spring and the
idle flow screw in their seatings.
- Refit the carburettor on the engine and connect
again the accelerator cable with the sheath and the
support plate and the electrical connection of the
starter.
- Reconnect the fuel supply pipe and tighten the 2
clamping screw fixing the carburettor to the inlet
manifold and the air inlet coupling to the filter.
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 requirements on lubrication, valve clearance,
and complying timing; spark plug should be in optimum conditions, air filter clean and sealed, and the
exhaust system tight.
- Connect the tester thermometer to 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.
Specific tooling
020331Y Digital multimeter
ENG - 120
Vespa S 50 4T 4V (2008)
Engine
- Using the rpm indicator in the analyser or a separate one, adjust the idle screw.
N.B.
THE WASTED SPARK IGNITION SYSTEM OFFERS REMARKABLE POWER. READINGS MAY NOT BE ACCURATE IF INADEQUATE RPM INDICATORS ARE USED.
Specific tooling
020332Y Digital rpm indicator
Characteristic
Idle speed
about 1900/2000 rpm
ENG - 121
INDEX OF TOPICS
SUSPENSIONS
SUSP
Vespa S 50 4T 4V (2008)
Suspensions
Front
Removing the front wheel
- Remove the five Allen screws that fix the wheel
to the hub.
N.B.
BEFORE REMOVING THE WHEEL HUB, REMOVE THE
BRAKE CALLIPER.
SUSP - 123
Suspensions
Front wheel hub overhaul
- Remove the ball bearing check Seeger ring indicated in the picture
Extract the ball bearing using the specific tool
Specific tooling
001467Y014 Pliers to extract ø 15-mm bearings
001467Y017 Bell for bearings, OD 39 mm
- 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
SUSP - 124
Vespa S 50 4T 4V (2008)
Vespa S 50 4T 4V (2008)
Suspensions
- 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 check 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
Soap-based lithium grease with NLGI 3; ISO-LXBCHA3, DIN K3K-20
Refitting the front wheel
- When refitting, tighten the 5 screws to the specified torque
Locking torques (N*m)
Nut tightening torque 20 to 25 N•m
Handlebar
SUSP - 125
Suspensions
Removal
Remove the handlebar cover before carrying out
this operation,.
- After removing the transmissions and disconnecting the electrical terminals, remove the terminal fixing the handlebar to the steering.
- Check all components and replace faulty parts.
N.B.
IF THE HANDLEBAR IS BEING REMOVED TO REMOVE
THE STEERING, TILT THE HANDLEBAR FORWARD TO
AVOIDING DAMAGING THE TRANSMISSIONS.
Refitting
Carry out the removal operations but in the reverse
order, observing the prescribed tightening torque.
Locking torques (N*m)
Handlebar lock nut 45 ÷ 50
Steering column
Removal
After removing the upper seat, lean the vehicle on
one side and extract the steering tube completely
from the fork.
Specific tooling
020055Y Wrench for steering tube ring nut
SUSP - 126
Vespa S 50 4T 4V (2008)
Vespa S 50 4T 4V (2008)
Suspensions
Overhaul
-The front suspension service operation is useful to replace the connecting parts between the steering
tube and the swinging hub of the front wheel holder, provided that the steering tube and the wheel holder
hub are in excellent conditions.
- Press and remove the wedging washer with the
help of a pointed end.
- For the second washer, repeat the operation using the punch on the side opposite to the one
shown in the figure.
A = Ø12 Punch
B = Sharp-edged end
- Use the specific tool, fitted with part 1*, and operate the handgrip until the pin and the Nadella are
simultaneously ejected in the direction opposite
the tool thrusting force.
- To eject the second Nadella, use the tool fitted
with part 2* instead of part 1, on the side opposite
the one shown in the figure.
* Supplied with the tool
Specific tooling
020021Y Front suspension service tool
- Use the tool fitted with part 20* and part 21* on
its stem as shown in the figure.
- Push the two roller casings with the handgrip until
their bottoms make contact with the pin end.
SUSP - 127
Suspensions
- Fit both dust guard rings «C» on the swinging hub
as shown in the detail drawing «A».
- Connect the swinging hub to the steering tube
with the guide pin, part 5*.
- Use the specific tool fitted with part 3* on its stem
and with part 4 at the bottom of the tool.
- Insert the previously greased pin on the swinging
hub and with the tool handgrip, move part 3 until it
stops on the steering tube.
- After fitting the pin, insert the two spacers, part
17*, slightly hitting with the mallet.
* Supplied with the tool
Specific tooling
020021Y Front suspension service tool
Recommended products
AGIP GREASE PV2 Grease for control levers
on the engine
White anhydrous-calcium based grease to protect
roller bearings; temperature range between -20 °
C and +120 °C; NLGI 2; ISO-L-XBCIB2
- Lubricate the sealing rings with mineral oil and
half-fill the roller casings with grease.
- Insert the sealing ring on the pin and the roller
bushing with wedging washers at the same time.
- Remove the specific tool, then the part 5 (guiding)
partially ejected in the previous assembly stage;
leave part 4* always fitted.
- Replace part 3 with part 16* on the stem.
- Push, from the handgrip, the wedging washer roller casing - sealing 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.
SUSP - 128
Vespa S 50 4T 4V (2008)
Vespa S 50 4T 4V (2008)
Suspensions
* Supplied with the tool
Specific tooling
020021Y Front suspension service tool
Recommended products
AGIP GREASE PV2 Grease for control levers
on the engine
White anhydrous-calcium based grease to protect
roller bearings; temperature range between -20 °
C and +120 °C; NLGI 2; ISO-L-XBCIB2
Use the tool fitted with parts 3 and 4, as indicated
to fit the pin, and press operating the handgrip,
until wedging the washers on 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.
* Supplied with the tool
N.B.
ASSEMBLE THE LOWER HOUSING ON HE STEERING
TUBE WITH A TUBE SECTION OF AN ADEQUATE DIAMETER.
Specific tooling
020021Y Front suspension service tool
001330Y Tool for fitting steering seats
Recommended products
AGIP GREASE PV2 Grease for control levers
on the engine
White anhydrous-calcium based grease to protect
roller bearings; temperature range between -20 °
C and +120 °C; NLGI 2; ISO-L-XBCIB2
SUSP - 129
Suspensions
Vespa S 50 4T 4V (2008)
Refitting
When fitting the fork, lubricate with the steering
bearing tracks with the recommended grease.
Tighten the lower ring nut "A" and the upper ring
nut "B" to the specified torque
Recommended products
AGIP GREASE PV2 Grease for the steering
bearings, pin seats and swinging arm
White anhydrous-calcium based grease to protect
roller bearings; temperature range between -20 C
and +120 C; NLGI 2; ISO-L-XBCIB2.
Locking torques (N*m)
Steering lower ring nut 8 ÷ 10 Upper steering
ring nut 35 ÷ 40
CAUTION
USE NEW ROLLER CASINGS, PIN, SEALING RINGS AND DUST GUARDS FOR REFITTING.
Front shock absorber
SUSP - 130
Vespa S 50 4T 4V (2008)
Suspensions
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 shock absorber upper clamp 20 ÷ 30
Shock-absorber - calliper bracket
Removal
- 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
SUSP - 131
Suspensions
- 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)
Lower shock absorber 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
- 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
SUSP - 132
Vespa S 50 4T 4V (2008)
Vespa S 50 4T 4V (2008)
Suspensions
- 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 52x55-mm Adaptor
- Assemble a new roller bearing on the shock absorber side and move it until it stops using the
specific tool
Specific tooling
020036Y Punch
- 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
Refitting
- Refit the parts in reverse order of the removal
operation.
CAUTION
BEFORE CARRYING OUT REFITTING OPERATIONS IN
THE AREAS MARKED WITH AN ASTERISK, LUBRICATE
THEM WITH THE RECOMMENDED PRODUCT
Specific tooling
020036Y Punch
020037Y Punch
Recommended products
AGIP GREASE PV2 Grease for control levers
on the engine
SUSP - 133
Suspensions
Vespa S 50 4T 4V (2008)
White anhydrous-calcium based grease to protect
roller bearings; temperature range between -20 °
C and +120 °C; NLGI 2; ISO-L-XBCIB2
Steering bearing
Removal
- Use the specific tool both to remove the lower seat of the upper bearing and to remove the upper seat
of the lower bearing fitted on the chassis.
N.B.
TO REMOVE THE LOWER SEAT OF THE LOWER STEERING BEARING JUST USE A SCREWDRIVER AS A LEVER BETWEEN THE SEATING AND THE SLEEVE.
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
Rear
Removing the rear wheel
-Straighten the split pin and remove the cap.
-Remove the wheel acting on the central fixing point.
SUSP - 134
Vespa S 50 4T 4V (2008)
Suspensions
Refitting the rear wheel
- Fit the wheel, tighten the nut to the prescribed
torque.
- Refit the cap and the split pin folding it correctly
as shown in the figure.
Locking torques (N*m)
Locking torque 137 ÷ 152 Nm
Swing-arm
Removal
Remove the swinging arm acting on the three
clamps shown in the figure.
SUSP - 135
Suspensions
Refitting
For rifting, respect the locking torques
Locking torques (N*m)
Part C 33 ÷ 41 Part B 44 ÷ 52 Part A 33 ÷ 41
Shock absorbers
SUSP - 136
Vespa S 50 4T 4V (2008)
Vespa S 50 4T 4V (2008)
Suspensions
Removal
- To replace the shock absorber remove the battery access flap to reach and remove the shock
absorber/ frame anchoring nut. Then remove the
shock absorber/engine anchorage nut.
- When refitting, tighten the shock absorber/chassis anchoring nut and the shock absorber/engine
pin to the prescribed torque.
Locking torques (N*m)
Shock absorber/engine pin torque 33 to 41 N·m
Shock absorber/frame nut torque 20 to 25 Nm
SUSP - 137
INDEX OF TOPICS
BRAKING SYSTEM
BRAK SYS
Vespa S 50 4T 4V (2008)
Braking system
1. Tank cover.
2 - Pump body.
3 - Brake lever.
4 - Pump plunger.
5- Oil delivery hose.
6 - Protection cap for air bleed screw.
7- Calliper.
8- Dust guard
9- Piston sealing ring.
10- Piston.
11 - Brake pad.
12 - Brake disc.
Front brake calliper
Removal
- Detach the oil brake hose from calliper, pouring
the fluid inside a container.
- Remove the mountings indicated in the figure.
- When refitting, tighten the nuts to the prescribed
torque.
- Bleed the system.
Locking torques (N*m)
Calliper tightening screw 20 ÷ 25 Nm Brake fluid
tube calliper 20 ÷ 25
Overhaul
- Remove the calliper assembling bolts and take out the internal bodies and components. If necessary,
in order to make it easier to take out the plungers, inject (shorts blasts of) compressed air through the
brake fluid pipe.
- Check that the cylinders of the internal and external body of the calliper do not show scratches or signs
of erosion; otherwise, replace the entire calliper.
CAUTION
ALL THE INTERNAL COMPONENTS MUST BE REPLACED EVERY TIME THE CALLIPER IS
SERVICED.
Fit to the calliper body:
- the sealing rings (1-2);
- the plungers (3);
BRAK SYS - 139
Braking system
Vespa S 50 4T 4V (2008)
- bed the O-Ring gasket (4) on a calliper body.
- Couple the internal body with the external one with assembling bolts. Refitting the pads and purging
air (see previous sections).
- Place the calliper on the disc and lock it to the support by tightening the bolts.
- Lock the pipe joint to the calliper to the prescribed torque.
Upon fitting, the parts must be perfectly clean and free of traces of oil, diesel fuel, grease, etc.. They
should be washed thoroughly in denatured alcohol before proceeding.
The sealing rings must be immersed in the operating liquid; the use of the PRF1 protection is
tolerated.
CAUTION
RUBBER PARTS SHOULD NEVER BE LEFT IN ALCOHOL FOR LONGER THAN 20 SECONDS.
AFTER WASHING, THE PIECES MUST BE DRIED WITH A BLAST OF COMPRESSED AIR AND A
CLEAN CLOTH.
Locking torques (N*m)
Screw tightening calliper to the support 20 ÷ 25 Attachment to the calliper 25 ÷ 30 Nm
1 DUST GUARDS
2 SEALING RINGS
3 PLUNGERS
4 O-RING GASKET
Front brake disc
Removal
- Should the brake disc be replaced, when refitting
the hub, apply recommended product on the fixing
bolts.
Tighten to the specified torque.
N.B.
THE SURFACE OF THE DISC WITH THE STAMPED ARROW INDICATING THE DIRECTION OF ROTATION MUST
FACE THE SHOCK ABSORBER.
Recommended products
Loctite 242 product description
Apply LOCTITE medium type 242 threadlock
Locking torques (N*m)
BRAK SYS - 140
Vespa S 50 4T 4V (2008)
Braking system
tightening torque 5 ÷ 6.5 Nm
Disc Inspection
Specific tooling
020335Y Magnetic support for dial gauge
Characteristic
Max oscillation allowed
0.1 mm.
Front brake pads
Removal
- Pads must be replaced when the friction material
thickness reaches the wear limit.
- To replace:
remove the protection cover, the bolt and the leaf
spring. Slide off the pads and replace them once
the plungers are down. Carry out these operations
in reverse order to fit.
CAUTION
BEFORE USING THE BRAKE, OPERATE THE LEVER A
FEW TIMES.
Front
-Once the bleed valve is closed, fill the system with
brake liquid to the maximum level.
-Undo the bleed screw.
-Apply the tube of the special tool to the bleed
screws.
When bleeding it is necessary to fill the oil tank in
continuation while working with a MITYVAC pump
on the bleed screws until no more air comes out of
the system.
BRAK SYS - 141
Braking system
The operation is finished when just oil comes out
of the bleed screws.
-Do up the bleed screw.
-When the operation is over, tighten up the oil
bleed screw to the prescribed torque.
N.B.
IF AIR CONTINUES TO COME OUT DURING PURGING, EXAMINE ALL THE FITTINGS:
IF SAID FITTINGS DO NOT SHOW SIGNS OF BEING FAULTY, LOOK FOR THE AIR INPUT AMONG THE VARIOUS
SEALS ON THE PUMP AND CALLIPER PISTONS.
CAUTION
- DURING THE OPERATIONS, THE VEHICLE MUST BE ON
THE STAND AND LEVEL.
N.B.
DURING PURGING FREQUENTLY CHECK THE LEVEL TO
PREVENT AIR GETTING INTO THE SYSTEM THROUGH
THE PUMP.
WARNING
- BRAKING CIRCUIT FLUID IS HYGROSCOPIC. IT ABSORBS HUMIDITY FROM THE SURROUNDING AIR.
IF THE LEVEL OF HUMIDITY IN THE BRAKING FLUID EXCEEDS A GIVEN VALUE, BRAKING EFFICIENCY WILL BE
REDUCED.
THEREFORE, ALWAYS USE FLUID FROM SEALED CONTAINERS.
UNDER NORMAL DRIVING AND CLIMATIC CONDITIONS
YOU SHOULD CHANGE THIS LIQUID EVERY TWO YEARS.
IF THE BRAKES ARE USED INTENSELY AND/OR IN
HARSH CONDITIONS, CHANGE THE FLUID MORE FREQUENTLY.
CAUTION
WHEN CARRYING OUT THE OPERATION, BRAKE FLUID
MAY LEAK FROM BETWEEN THE BLEED SCREW AND ITS
SEAT ON THE CALLIPER.
CAREFULLY DRY THE CALLIPER AND DEGREASE THE
DISC SHOULD THERE BE OIL ON IT.
Specific tooling
020329Y MityVac vacuum-operated pump
Recommended products
AGIP BRAKE 4 Brake fluid
FMVSS DOT 4 Synthetic fluid
Locking torques (N*m)
Oil bleed screw 7 ÷ 10
Front brake pump
BRAK SYS - 142
Vespa S 50 4T 4V (2008)
Vespa S 50 4T 4V (2008)
Braking system
Removal
- Bleed the circuit and drain the brake fluid through
the bleeding screw located on the calliper and actuate the brake lever until no more fluid flows out.
-Remove the oil pump from the handlebar; remove
the brake lever and then remove the wheel cylinder.
1 - Tank cap screw.
2. Tank cover.
3. Diaphragm.
4. Bellows.
5. Sealing ring.
6. Piston.
7. Gasket.
8 - Spring
CAUTION
- THE PRESENCE OF BRAKE FLUID ON THE DISC OR
BRAKE PADS REDUCES THE BRAKING EFFICIENCY.
IN THIS CASE, REPLACE THE PADS AND CLEAN THE
DISC WITH A HIGH-QUALITY SOLVENT.
CONTACT WITH BRAKE FLUID WILL DAMAGE PAINTED
SURFACES.
RUBBER PARTS SHOULD NEVER BE LEFT IN ALCOHOL
FOR LONGER THAN 20 SECONDS.
AFTER WASHING, THE PIECES MUST BE DRIED WITH A
BLAST OF COMPRESSED AIR AND A CLEAN CLOTH.
THE SEALING RINGS MUST BE IMMERSED IN THE OPERATING LIQUID.
Refitting
Before fitting, the parts must be perfectly clean and
free of traces of oil, diesel fuel, grease, etc.. They
should be washed thoroughly in denatured alcohol
before proceeding.
- Reinstall the individual parts in the reverse order
to the removal, paying attention to the correct positioning of the rubber parts in order to ensure leak
tightness.
1 - Tank cap screw.
2. Tank cover.
3. Diaphragm.
4. Bellows.
BRAK SYS - 143
Braking system
5. Sealing ring.
6. Piston.
7. Gasket.
8. Spring.
Rear drum brake
Once the muffler and the wheel have been removed, follow these steps:
1.Remove the shoe spring using the specific spanner.
2. Remove the shoe with the aid of a lever.
3. Refit the new shoes giving a few taps with the
mallet.
4. Attach the spring using the specific pliers.
Specific tooling
020325Y Pliers for brake-shoe springs
BRAK SYS - 144
Vespa S 50 4T 4V (2008)
INDEX OF TOPICS
CHASSIS
CHAS
Chassis
Seat
- Lift the saddle and remove the helmet compartment «A».
- Undo the two screws indicated.
Rear handlebar cover
- Remove the front handlebar cover.
- Undo the three screws indicated in figure fixing it
to the handlebar, the odometer transmission and
the electrical connectors.
CHAS - 146
Vespa S 50 4T 4V (2008)
Vespa S 50 4T 4V (2008)
Chassis
Instrument panel
- Remove the rear handlebar cover.
- Undo the three screws indicated fixing the rear
handlebar cover.
Front handlebar cover
Proceed as follows:
-Remove the rear-view mirrors.
- Undo the two screws «A».
- Undo the screw «B» and remove the front handlebar cover.
- Disconnect the electrical terminals and remove
the turn indicator bulb.
CHAS - 147
Chassis
Headlight assy.
- Remove the front handlebar cover.
- Undo the four screws indicated fixing the front
handlebar cover.
Knee-guard
- Undo the five screws indicated.
- Remove the rubber strip from both sides and undo the indicated screw.
- Remove the shield back plate bringing it to the
rear part of the scooter.
CHAS - 148
Vespa S 50 4T 4V (2008)
Vespa S 50 4T 4V (2008)
Chassis
Taillight assy.
- Undo the two fixing screws and remove the rear
light unit.
- Undo the screw indicated and disconnect the
connector.
Footrest
- Remove the shield back plate.
- Remove the side fairings.
- Remove the central tunnel inspection door.
From both sides, unscrew:
- The fixing screw at the back.
- The fixing screw on the central part.
CHAS - 149
Chassis
- The fixing screw at the front.
- Remove the footrest.
Side fairings
- Undo the screw «A» and the smaller screw «B».
- Detach the seats on the fairing.
CHAS - 150
Vespa S 50 4T 4V (2008)
Vespa S 50 4T 4V (2008)
Chassis
License plate holder
- Remove the side fairings.
- Working on both sides, undo the two screws indicated.
- Remove the license plate light.
Air filter
- Remove the helmet compartment.
- Remove the side fairings.
- Undo the two indicated clamps to the crankcase.
- Undo the two clamps indicated.
CHAS - 151
Chassis
Fuel tank
CHAS - 152
Vespa S 50 4T 4V (2008)
Vespa S 50 4T 4V (2008)
Chassis
- Adequately support the rear part of the scooter.
- Remove the wheel and the rear mudguard.
- Remove the battery compartment.
- Disconnect the fuel outlet pipe.
- Undo the two fixing screws to the chassis and
collect the fuel pipe supporting plate.
CHAS - 153
Chassis
- Remove the turn indicators.
- Remove the rear light unit and undo the indicated
screw.
- Unscrew the closing cap.
- Lower the fuel tank and disconnect the bleed
pipes and the level indicator connector.
- Remove the tank.
CHAS - 154
Vespa S 50 4T 4V (2008)
Vespa S 50 4T 4V (2008)
Chassis
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
Front central cover
- Remove the "Piaggio" clip-on badge.
- Undo the two screws indicated.
- Remove the front central cover, sliding it upwards.
CHAS - 155
INDEX OF TOPICS
PRE-DELIVERY
PRE DE
Vespa S 50 4T 4V (2008)
Pre-delivery
Aesthetic inspection
- Paintwork
- Fitting plastics parts
- Damage
- Dirt
Tightening torques inspection
Lock check
- All tightening torques
- External screw of covers
SAFETY LOCKS
Name
Handlebar locking
Steering lower ring nut
Upper steering ring nut
Front wheel axle nut
Rear wheel nut
Rear shock absorber nut-engine
Shock absorber - chassis nut
Engine-swinging arm bolt
Frame-swinging arm bolt
Torque in Nm
40 ÷ 50
8 ÷ 10
30 ÷ 40
75 ÷ 90
137 ÷ 152
33 to 41 N·m
20 ÷ 25
33 ÷ 41
44 ÷ 52
Electrical system
- Check voltage at pre-delivery; it should be 12.6V minimum; otherwise, recharge the battery following
the specifications indicated on the battery itself.
Check the following devices:
- Key switch
- Low-beam light, high-beam light, light warning lights, position light
- Headlight adjustment
- Rear light
- Stop light (front and rear brake, if required)
- Turn indicators and relevant warning lights
- Speedometer and instrument panel lighting
- Horn
- Starter button
CAUTION
IN ORDER TO ENSURE MAXIMUM PERFORMANCE CHARGE THE BATTERY BEFORE USE ONLY IF VOLTAGE DROPS BELOW 12.7 V. FAILURE TO CHARGE THE BATTERY ADEQUATELY
BEFORE IT IS FIRST USED SHORTENS BATTERY LIFE.
WHEN INSTALLING THE BATTERY, ATTACH THE POSITIVE LEAD FIRST AND THEN THE NEGATIVE LEAD.
PRE DE - 157
Pre-delivery
Vespa S 50 4T 4V (2008)
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.
WARNING
KEEP THE BATTERY AWAY FROM NAKED FLAMES OR SPARKS WHILE IT IS CHARGED.
REMOVE THE BATTERY FROM THE SCOOTER, DISCONNECTING THE NEGATIVE TERMINAL
FIRST.
ALWAYS WEAR EYE PROTECTION WHEN WORKING IN THE PROXIMITY OF BATTERIES.
KEEP OUT OF THE REACH OF CHILDREN. BATTERY ELECTROLYTE IS TOXIC AND IT MAY
CAUSE SERIOUS BURNS. IT CONTAINS SULPHURIC ACID. AVOID CONTACT WITH YOUR
EYES, SKIN AND CLOTHING. NEVER TRY TO FORCE OR DAMAGE THE OUTER CASING.
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.
Levels check
- Brake oil level
- Hub oil level
- Engine oil level
Road test
- Cold start.
- Speedometer activation check.
- Throttle control operation.
- Riding stability.
- Front and rear brake efficiency.
- Front and rear wheel shock absorber efficiency.
- Abnormal noise.
- Hot engine restart.
- Fluid leak (after test drive).
Functional inspection
- Brake lever travel.
- Throttle control adjustment and free travel.
- Uniform turning of the steering.
Others
- Tyre pressure
- Correct operation of all locks
- Mirrors and accessories fitting
- Tools supplied, user's manual, warranty certificate and customer services documents
CAUTION
PRE DE - 158
Vespa S 50 4T 4V (2008)
Pre-delivery
CHECK AND ADJUST TYRE PRESSURE WITH TYRES AT AMBIENT TEMPERATURE.
CAUTION
NEVER EXCEED THE RECOMMENDED INFLATION PRESSURES OR TYRES MAY BURST.
WARNING
BE VERY CAREFUL WHEN HANDLING FUEL.
PRE DE - 159
INDEX OF TOPICS
TIME
TIME
Vespa S 50 4T 4V (2008)
Time
Engine
ENGINE
1
Code
001001
2
003064
Action
Engine from frame - Removal and refit.
Engine oil - Change
Duration
TIME - 161
Vespa S 50 4T 4V (2008)
Time
Crankcase
CRANKCASE
1
Crankshaft
TIME - 162
Code
001133
Action
Engine crankcase - Replacement
Duration
Vespa S 50 4T 4V (2008)
Time
CRANKSHAFT
1
2
3
4
Code
001117
001099
001100
001118
Action
Crankshaft - Replacement
Oil seal, flywheel side - Replacement
Oil seal, clutch side - Replacement
Main bearings - Replacement
Duration
Cylinder assy.
CYLINDER- PISTON
1
2
Code
001002
001107
Action
Cylinder Piston - Replacement
Cylinder Piston - Inspection /Cleaning
Duration
TIME - 163
Vespa S 50 4T 4V (2008)
Time
Cylinder head assy.
HEAD
1
2
3
TIME - 164
Code
001056
001045
001126
Action
Head gasket - Replacement
Valves - Replacement
Head - Replacement
Duration
Vespa S 50 4T 4V (2008)
Time
Rocker arms support assy.
CAMSHAFT SUPPORT
1
2
3
Code
001049
001148
001044
Action
Valve clearance - Adjustment
Valve rocking levers - Replacement
Camshaft - Replacement
Duration
TIME - 165
Vespa S 50 4T 4V (2008)
Time
Cylinder head cover
HEAD COVER
1
2
3
4
TIME - 166
Code
001093
001088
001097
001089
Action
Spark plug - Replacement
Head cover gasket - Replacement
Cooling hood - Replacement
Head cover - Replacement
Duration
Vespa S 50 4T 4V (2008)
Time
Driven pulley
DRIVEN PULLEY - CLUTCH
1
2
3
4
Code
001110
001012
001022
001155
Action
Driven pulley - Replacement
Driven pulley - Overhaul
Clutch - Replacement
Clutch bell housing - Replacement
Duration
TIME - 167
Vespa S 50 4T 4V (2008)
Time
Oil pump
OIL PUMP
1
2
3
4
5
6
7
8
TIME - 168
Code
001051
001112
001042
001121
001122
001125
001130
001129
Action
Belt/Timing chain - Change
Oil pump - change
Oil pump - Service
Chain cover oil seal - Replacement
Oil pump chain - Replacement
Chain guide pads - Replacement
Oil sump - Replacement
Chain tightener - Overhaul and replacement
Duration
Vespa S 50 4T 4V (2008)
Time
Final gear assy.
FINAL REDUCTION GEAR ASSEMBLY
1
2
Code
004125
001156
3
4
003065
001010
Action
Rear wheel axle - Replacement
Gear reduction unit cover - Replacement
Gear box oil - Replacement
Gear reduction unit - Inspection
Duration
TIME - 169
Vespa S 50 4T 4V (2008)
Time
Driving pulley
REAR-VIEW
1
Code
001177
2
3
4
001086
001066
001011
TIME - 170
PULLEY
Action
Variator rollers / shoes - Replacement
rear-view half-pulley - Replacement
Driving pulley - Removal and refitting
Driving belt - Replacement
Duration
Vespa S 50 4T 4V (2008)
Time
Transmission cover
TRANSMISSION COVER
1
Code
001096
2
001132
3
001131
4
001135
Action
Transmission crankcase cover - replace
Transmission air inlet pipe - Replacement
Transmission air intake - Replacement
Transmission cover bearing - Replacement
Duration
TIME - 171
Vespa S 50 4T 4V (2008)
Time
Starter motor
ELECTRICAL START-UP
1
2
Code
001020
005045
3
001017
4
5
6
001021
008008
001084
TIME - 172
Action
Starter motor - Replacement
Starter motor cable harness - Replacement
Starter sprocket wheel - Replacement
Kick starter - Inspection
Starter spring pack - Replacement
Starter lever - Replacement
Duration
Vespa S 50 4T 4V (2008)
Time
Flywheel magneto
MAGNETO FLYWHEEL
1
2
3
4
5
6
Code
001067
001173
001102
001109
001087
001058
Action
Stator - Fitting and Refitting
Rotor - Replacement
Net oil filter - Replacement / Cleaning
Cooling fan - Replacement
Flywheel cover - Replacement
Flywheel - Replacement
Duration
TIME - 173
Vespa S 50 4T 4V (2008)
Time
Carburettor
CARBURETTOR
1
2
3
4
5
Code
001063
001008
003058
001081
001082
6
001013
TIME - 174
Action
Carburettor - Replacement
Carburettor - Inspection
Carburettor - Adjustment
Automatic choke - Replacement
Carburettor heating resistor - Replacement
Intake manifold - change
Duration
Vespa S 50 4T 4V (2008)
Time
Exhaust pipe
MUFFLER
1
2
3
Code
001009
001095
001136
Action
Muffler - Replacement
Muffler guard - Replacement
Exhaust emissions - Adjustment
Duration
TIME - 175
Vespa S 50 4T 4V (2008)
Time
Air cleaner
AIR CLEANER
1
Code
004122
2
3
001014
001015
TIME - 176
Action
Air cleaner carburettor fitting - Replacement
Air filter - Replacement / cleaning
Air filter box - Replacement
Duration
Vespa S 50 4T 4V (2008)
Time
Frame
FRAME
1
2
3
4
5
6
Code
004001
004023
004149
004159
004012
004059
Action
Frame - Replacement
Shield rim - Replacement
Shield central cover - Replacement
Plates / Stickers - Replacement
Rear side panels - Replacement
Spark plug inspection flap - Replacement
Duration
TIME - 177
Vespa S 50 4T 4V (2008)
Time
Centre-stand
STAND
1
2
TIME - 178
Code
004004
004171
Action
Stand - Replacement
Stand support plate - Replacement
Duration
Vespa S 50 4T 4V (2008)
Time
Footrests
FOOTREST
1
2
Code
004178
004078
Action
Footrest - Replacement
Front/rear footrest rubber - Replacement
Duration
TIME - 179
Vespa S 50 4T 4V (2008)
Time
Rear cover
SHIELD BACK PLATE
1
2
Code
004174
004065
3
4
004081
004082
TIME - 180
Action
Trunk levers - Replacement
Legshield, rear part - Removal and
refitting
Glove box door - Replacement
Top box gasket - Replacement
Duration
Vespa S 50 4T 4V (2008)
Time
Underseat compartment
HELMET COMPARTMENT
1
2
3
4
Code
004016
005046
004011
004071
Action
Helmet compartment - Replacement
Battery cover - change
Central frame cover - Replacement
Battery compartment - replacement
Duration
TIME - 181
Vespa S 50 4T 4V (2008)
Time
Plate holder
LICENSE PLATE HOLDER
1
Code
004136
2
3
005048
005032
TIME - 182
Action
License plate holder support - Replacement
Licence plate holder - Replacement
number plate light glass - Replacement
Duration
Vespa S 50 4T 4V (2008)
Time
Mudguard
MUDGUARDS
1
2
Code
004002
004009
Action
Front mudguard - Replacement
Rear mudguard - Replacement
Duration
TIME - 183
Vespa S 50 4T 4V (2008)
Time
Fuel tank
FUEL TANK
1
2
3
Code
004168
005010
004112
4
5
6
004005
004007
004109
TIME - 184
Action
Fuel tank cap - Replacement
Tank float - Replacement
Cock-carburettor hose - Replacement
Fuel tank - Replacement
Fuel valve - Replacement
Fuel tank breather - change
Duration
Vespa S 50 4T 4V (2008)
Time
Rear shock-absorber
REAR SHOCK ABSORBER
1
Code
003007
Action
Rear shock absorber - Removal and
Refitting
Duration
TIME - 185
Vespa S 50 4T 4V (2008)
Time
Steering column bearings
STEERING FIFTH WHEELS
1
2
3
TIME - 186
Code
003002
003073
004119
Action
Steering fifth wheels - Replacement
Steering clearance - Adjustment
Bearing / upper steering fifth wheel Replacement
Duration
Vespa S 50 4T 4V (2008)
Time
Handlebar covers
ODOMETER - HANDLEBAR COVERS
1
Code
004018
2
004019
3
4
005014
005038
5
005078
Action
Handlebar front section - Replacement
Handlebar rear section - Replacement
Odometer - Replacement
Instrument panel warning light bulbs
- Replacement
Odometer glass - Replacement
Duration
TIME - 187
Vespa S 50 4T 4V (2008)
Time
Handlebar components
HANDLEBAR COMPONENTS
1
2
3
4
5
6
Code
004066
002037
002071
003001
005017
002024
7
002063
8
002060
9
004162
10
002059
TIME - 188
Action
Driving mirror - Replacement
Brake or clutch lever - Replacement
Left hand grip - Replacement
Handlebar - Replacement
Stop switch - Replacement
Front brake pump - Removal and Refitting
Throttle control transmission - Replacement
Complete throttle control - Replacement
Mirror support and/or brake pump fitting U-bolt - Replacement
Right hand grip - Replacement
Duration
Vespa S 50 4T 4V (2008)
Time
Swing-arm
SWINGING ARM
1
Code
001072
Action
Engine-frame connection swinging
arm - Replacement
Duration
TIME - 189
Vespa S 50 4T 4V (2008)
Time
Seat
SADDLE
1
2
TIME - 190
Code
004003
004131
Action
Saddle - Replacement
Luggage rack support - Replacement
Duration
Vespa S 50 4T 4V (2008)
Time
Turn signal lights
TURN INDICATOR LIGHTS
1
2
3
Code
005002
005012
005067
4
5
6
7
005008
005005
005066
005022
8
005068
Action
Front headlamp - change
Front turn indicator - Replacement
Front turn indicator bulb - Replacement
Front headlamp bulbs - Replacement
Taillight - Replacement
Rear light bulbs - Replacement
Rear turning indicators - Replacement
Rear turning indicator bulb - Replacement
Duration
TIME - 191
Vespa S 50 4T 4V (2008)
Time
Front wheel
FRONT WHEEL
1
2
3
4
5
6
Rear wheel
TIME - 192
Code
004123
003047
003037
003033
002041
003034
Action
Front wheel - Replacement
Front tyre - Replacement
Front wheel rim - Replacement
Front wheel hub- Replacement
Front brake disc - Replacement
Front wheel hub bearing - Replacement
Duration
Vespa S 50 4T 4V (2008)
Time
REAR WHEEL
1
2
Code
004126
001071
3
4
001016
002002
Action
Rear wheel tyre - Replacement
Rear wheel rim - Removal and Refitting
Rear wheel - Replacement
Rear brake pads/shoes - Repl.
Duration
Electric devices
ELECTRICAL COMPONENTS
1
2
Code
005001
005011
3
4
5
6
7
8
005009
005007
005052
001023
001094
001069
Action
Electrical system - Replacement
Starter remote control switch - Replacement
Voltage regulator - Replacement
Battery - change
Fuse (1) - Replacement
Control unit - Replacement
Spark plug cap - Replacement
HV coil - Replacement
Duration
TIME - 193
Vespa S 50 4T 4V (2008)
Time
Electronic controls
ELECTRIC CONTROLS
1
2
Code
005039
005006
3
4
5
6
7
8
005040
005003
005041
005016
004096
004010
TIME - 194
Action
Lights switch - Replacement
Light or turning indicator switch - Replacement
Horn button - Replacement
Horn - Replacement
Starter button - Replacement
Key switch - Replacement
Lock series - Replacement
Antitheft lock - Replacement
Duration
Vespa S 50 4T 4V (2008)
Time
Transmissions
TRANSMISSIONS
1
Code
002053
2
002051
3
002049
Action
Rear brake transmission complete Replacement
Odometer transmission assembly Replacement
Odometer cable - Replacement
Duration
TIME - 195
Vespa S 50 4T 4V (2008)
Time
Front suspension
FRONT SUSPENSION
1
2
3
Code
003045
003010
003035
4
5
001064
003044
TIME - 196
Action
Steering tube - Replacement
Front suspension - Service
Shock absorber support and brake
calliper - Replacement
Odometer reel - Replacement
Shock absorber cover - Replacement
Duration
Vespa S 50 4T 4V (2008)
Time
Braking system
BRAKING SYSTEM
1
Code
002021
2
002007
3
002039
4
002047
5
002002
Action
Front brake hose - Remov. and Refitt.
Front brake shoes/pads - Remov.
and Refitt
Front brake calliper - Removal and
Refitting
Front brake fluid and air bleed system - Replacement
Shoes - Rear brake pads - Replacement
Duration
TIME - 197
Vespa S 50 4T 4V (2008)
Time
Secondary air box
SECONDARY AIR HOUSING
1
Code
001164
2
001161
3
001162
4
001163
5
001165
TIME - 198
Action
Crankcase secondary air connection
- Replacement
Secondary air filter - Replacement /
Cleaning
Secondary air housing - Replacement
Muffler secondary air connection Replacement
Secondary air reed - Replacement
Duration
A
Air filter: 40, 151
B
Battery: 49
Brake: 139–142, 144
C
Carburettor: 36, 112, 115, 174
E
Engine oil: 40
Engine stop:
F
Fuel: 48, 111, 152, 184
H
Headlight: 43, 148
Hub oil: 39
I
Identification: 8
Instrument panel: 147
M
Maintenance: 7, 36
O
Odometer:
Oil filter: 41
S
Saddle:
Shock absorbers: 136
Spark plug: 38, 53
Stand:
Start-up:
T
Tank: 152, 184
Transmission: 9, 48, 64, 74, 171
Tyres: 13