VESPA ET4 50 Specifications

WORKSHOP MANUAL
633367
ET4 50
WORKSHOP
MANUAL
ET4 50
The descriptions and illustrations given in this publication are not binding. While the basic specifications
as described and illustrated in this manual remain unchanged, PIAGGIO-GILERA reserves the right, at
any time and without being required to update this publication beforehand, to make any changes to
components, parts or accessories, which it considers necessary to improve the product or which are
required for manufacturing or construction reasons.
Not all versions/models shown in this publication are available in all countries. The availability of single
versions should be checked at the official Piaggio sales network.
"© Copyright 2007 - PIAGGIO & C. S.p.A. Pontedera. All rights reserved. Reproduction of this publication
in whole or in part is prohibited."
PIAGGIO & C. S.p.A. - After-Sales
V.le Rinaldo Piaggio, 23 - 56025 PONTEDERA (Pi)
WORKSHOP MANUAL
ET4 50
This workshop manual has been drawn up by Piaggio & C. Spa to be used by the workshops of PiaggioGilera dealers. This manual is addressed to Piaggio service mechanics who are supposed to have a
basic knowledge of mechanics principles and of vehicle fixing techniques and procedures. Any important
changes made to the vehicles or to specific fixing operations will be promptly reported by updates to this
manual. Nevertheless, no fixing work can be satisfactory if the necessary equipment and tools are
unavailable. It is therefore advisable to read the sections of this manual relating to specific tools, along
with the specific tool catalogue.
N.B. Provides key information to make the procedure easier to understand and carry out.
CAUTION Refers to specific procedures to carry out for preventing damages to the vehicle.
WARNING Refers to specific procedures to carry out to prevent injuries to the repairer.
Personal safety Failure to completely observe these instructions will result in serious risk of personal
injury.
Safeguarding the environment Sections marked with this symbol indicate the correct use of the vehicle
to prevent damaging the environment.
Vehicle intactness The incomplete or non-observance of these regulations leads to the risk of serious
damage to the vehicle and sometimes even the invalidity of the guarantee.
INDEX OF TOPICS
CHARACTERISTICS
CHAR
TOOLING
TOOL
MAINTENANCE
MAIN
TROUBLESHOOTING
TROUBL
ELECTRICAL SYSTEM
ELE SYS
ENGINE FROM VEHICLE
ENG VE
ENGINE
ENG
SUSPENSIONS
SUSP
BRAKING SYSTEM
CHASSIS
PRE-DELIVERY
TIME
BRAK SYS
CHAS
PRE DE
TIME
INDEX OF TOPICS
CHARACTERISTICS
CHAR
ET4 50
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 spares may damage the vehicle.
- Use only the appropriate tools designed for this vehicle.
- Always use new gaskets, sealing rings and split pins upon refitting.
- After removal, clean the components using non-flammable or low flash-point 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 sizes. 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
ET4 50
Characteristics
Vehicle identification
VEHICLE IDENTIFICATION
Specification
Frame prefix
Engine prefix
Desc./Quantity
ZAPC2610000001001
C261M
Dimensions and mass
DIMENSIONS AND MASS
Specification
Total unloaded kerb weight
Width
Length
Wheelbase
Height
CHAR - 8
Desc./Quantity
105 Kg
710 mm
1780 mm
1275 mm
1090 mm
ET4 50
Characteristics
Engine
ENGINE
Specification
Type
Bore
Stroke
Cubic capacity
Compression ratio
Timing system
Vacuum carburettor
CO adjustment
Engine idle
Air filter
Starting system
Lubrication
Fuel supply
Max. power (crankshaft)
Cooling system
Valve clearance (cold engine)
Desc./Quantity
single-cylinder, four-stroke
39 mm
41,8 mm
49.93 cm³
11,5 ÷ 12 : 1
single overhead camshaft, driven by a chain to the left side.
KEIHIN CVK Ø 18 mm
WALBRO WP 16A
3,2% ± 0,5
1900 ÷ 2000 rpm.
Sponge impregnated with fuel mixture (50% SELENIA air filter
oil and 50% unleaded petrol).
electric starter/kickstarter
engine lubrication with lobe pump (in the crankcase) driven by
a chain. Mesh prefilter and centrifugal on the crankshaft
Gravity feed, with unleaded petrol (with a minimum octane rating of 95) with carburettor.
2,5 KW (3,4 CV) at 6500 rpm.
forced coolant circulation system
intake 0.10 mm
discharge 0.15 mm
Transmission
TRANSMISSION
Specification
Transmission
Desc./Quantity
With automatic expandable pulley variator, torque server, V
belt, automatic clutch, gear reduction unit.
Capacities
CAPACITIES
Specification
Fuel tank (including ~ 2.3 l reserve)
Rear hub
Engine oil
Desc./Quantity
~ 9l
80 cc
~ 850 cc
Electrical system
ELECTRICAL COMPONENTS
Specification
Type of ignition
Desc./Quantity
Capacitive discharge type electronic ignition, with incorporated
high voltage coil
Ignition advance variable, with microprocessor (before T.D.C.)
10° at 1800-2000 rpm
26° at 5000-6000 rpm
Spark plug
Champion RG 4 PHP
Champion RG 4 HC
Battery
12V-9Ah
Fuse
10A
Generator
single-phase alternating current
CHAR - 9
ET4 50
Characteristics
Frame and suspensions
FRAME AND SUSPENSIONS
Specification
Type
Front suspension
Front suspension stroke
Trail (suspension rebounded/compressed)
Rear suspension
Rear suspension bump position
Desc./Quantity
Unitised body made of stamped plate
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, helicoidal coaxial spring. Chassis engine support with swinging arm.
80 mm
Brakes
BRAKES
Specification
Front brake
Rear brake
Desc./Quantity
Disc brake Ø 200 mm with hydraulic linkage (r.h brake lever).
Drum brake Ø 110 mm with mechanical linkage.
Wheels and tyres
WHEELS AND TYRES
Specification
Front tyre dimension
Rear tyre size
Front tyre pressure:
Rear tyre pressure:
Lightweight alloy wheels (front)
Light alloy rims (rear rim)
Desc./Quantity
100/80-10"
120/70-10"
1,3 bar
1,8 ÷ 2 bar
2,15" x 10"
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.
Carburettor
50cc Version
Kehin
CARBURETTOR KEHIN
Specification
Manufacturer and Type
Type
Choke diameter
Maximum thrust
Minimum jet
Starter jet
Emulsioner
Tapered pin stamping
Notches from the top
CHAR - 10
Desc./Quantity
KEHIN CVK 18
vacuum
Ø 18 mm
75
35
42
Ø 2,1 mm
NACA
the rod has no notches
ET4 50
Characteristics
Specification
Fuel inlet hole
Starter piston protrusion
Desc./Quantity
Ø 1,2 mm
11 mm at 24°C
Tightening Torques
STEERING ASSEMBLY
Name
Upper steering ring nut
Lower steering ring nut
Handlebar fastening
Torque in Nm
30 ÷ 40
8 ÷ 10
45 ÷ 50
FRAME ASSEMBLY
Name
Engine-swinging arm bolt
Floating arm-frame pin
Shock absorber - chassis nut
Shock absorber-engine nut
Rear wheel nut
Speedometer gear plate fixing screw
Torque in Nm
33 ÷ 41
44 ÷ 52
20 ÷ 25
33 ÷ 41
137 ÷ 152
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
(°)Tighten these two bolts after tightening the shock absorber central upper nut.
N.B.
FOR INFORMATION ON SAFETY TIGHTENINGS, REFER TO CHAPTER «PRE-CONSIGNMENT
CHECKS».
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
Spark plug:
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
Rocker-arm 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
Torque in Nm
10 ÷ 15 Nm
8 ÷ 10
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
CHAR - 11
ET4 50
Characteristics
Name
Oil decantation labyrinth sheet screws
Oil pump crown screw
Screws fixing oil pump to crankcase
Oil sump screws
Inlet manifold screw
Manifold/carburettor clamp screw
Screws fixing cables to starter motor
Starter motor 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 cover screws
Wheel axle nut
Crankcase half union screw
Torque in Nm
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
115 ÷ 125
8 ÷ 10
*When new stud bolts are assembled, tighten them with 3 turns at 90° after the first tightening at 6-7
N·m, therefore 6-7 N·m + 90 ° + 90 ° + 90 °, in a crosswise manner.
Overhaul data
Assembly clearances
Cylinder - piston assy.
PISTON AND CYLINDER MATING
Name
Cylindre Ø C (39
±0,014)
Cylindre Ø C (39
±0,014)
Piston Ø P (38,968
±0,014)
CHAR - 12
Initials
A
Cylinder
38,986 ÷ 38,993
Piston
38,954 ÷ 38,961
Play on fitting
0,025 ÷ 0,039
B
38,993 ÷ 39,000
38,961 ÷ 38,968
0,025 ÷ 0,039
C
39,000 ÷ 39,007
38,968 ÷ 38,975
0,025 ÷ 0,039
ET4 50
Name
Piston Ø P (38,968
±0,014)
Cylindre 1st oversize Ø
C (39,2 ±0,014)
Cylindre 1st oversize Ø
C (39,2 ±0,014)
Piston 1st oversize Ø P
(39,168 ±0,014)
Piston 1st oversize Ø P
(39,168 ±0,014)
Cylindre 2nd oversize Ø
C (39,4 ±0,014)
Cylindre 2nd oversize Ø
C (39,4 ±0,014)
Piston 2nd oversize Ø P
(39,368 ±0,014)
Piston 2nd oversize Ø P
(39,368 ±0,014)
Cylindre 3rd oversize Ø
C (39,6 ±0,014)
Cylindre 3rd oversize Ø
C (39,6 ±0,014)
Piston 3rd oversize Ø P
(39,568 ±0,014)
Piston 3rd oversize Ø P
(39,568 ±0,014)
Characteristics
Initials
D
Cylinder
39,007 ÷ 39,014
Piston
38,975 ÷ 38,982
Play on fitting
0,025 ÷ 0,039
A1
39,186 ÷ 39,193
39,154 ÷ 39,161
0,025 ÷ 0,039
B1
39,193 ÷ 39,200
39,161 ÷ 39,168
0,025 ÷ 0,039
C1
39,200 ÷ 39,207
39,168 ÷ 39,175
0,025 ÷ 0,039
D1
39,207 ÷ 39,214
39,175 ÷ 39,182
0,025 ÷ 0,039
A2
39,386 ÷ 39,393
39,354 ÷ 39,361
0,025 ÷ 0,039
B2
39,393 ÷ 39,400
39,361 ÷ 39,368
0,025 ÷ 0,039
C2
39,400 ÷ 39,407
39,368 ÷ 39,375
0,025 ÷ 0,039
D2
39,407 ÷ 39,414
39,375 ÷ 39,382
0,025 ÷ 0,039
A3
39,586 ÷ 39,593
39,554 ÷ 39,561
0,025 ÷ 0,039
B3
39,593 ÷ 39,600
39,561 ÷ 39,568
0,025 ÷ 0,039
C3
39,600 ÷ 39,607
39,568 ÷ 39,575
0,025 ÷ 0,039
D3
39,607 ÷ 39,614
39,575 ÷ 39,582
0,025 ÷ 0,039
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
Piston rings
UPRATING TABLE
Name
1° Compression lining
2° Compression lining
Scraper ring lining
1° Compression lining
1° greater
2° Compression lining
1° greater
Scraper ring lining 1°
greater
1° Compression lining
2° greater
2° Compression lining
2° greater
Scraper ring lining 2°
greater
1° Scraper ring lining 3°
greater
2° Scraper ring lining 3°
greates
Description
CHAR - 13
ET4 50
Characteristics
Name
Scraper ring lining 3°
greates
Description
Dimensions
39,6 x 2
Initials
A
Quantity
0,20 ÷ 0,70
Crankcase - crankshaft - connecting rod
END PLAY BETWEEN DRIVING SHAFT AND CONNECTING ROD
Name
Transmission side half
shaft
Flywheel side half shaft
Connecting rod
Spacing tool
Description
Dimensions
14 +0 -0.005
Initials
A
16 +0 -0.005
14.8 +0.05 -0
45,00 / assembly
games D = 0,15 ÷ 0,30
B
C
E
Quantity
Slot packing system
Shimming method for limiting the compression ratio
Rc = 11,5 ÷ 12
A = MEASUREMENT «A» (WITH PISTO AT T.D.C.)
B = MEASUREMENT «A» IS TO BE TAKEN WITHOUT ANY GASKET BETWEEN THE CRANKCASE
AND THE CYLINDER
C = FIT THE GASKET SHOWN IN THE TABLE ACCORDING TO SIZE «A»
CHAR - 14
ET4 50
Characteristics
N.B.
MEASUREMENT «A» IS A PISTON RECESS VALUE
The more the piston protrudes out of the plane generated by the top section of the cylinder, the thicker
the gasket to be applied (to recover the compression ratio) and vice-versa.
THICKNESS (IN FIBER)
Specification
CYLINDER HEIGHT
HEAD GASKET THICKNESS (IN FIBER)
MEASUREMENT 0,9 ± 0,05
MEASUREMENT 1 ± 0,05
Desc./Quantity
57,15 ± 0,05
0,95 ± 0,06
BASE GASKET THICKNESS 0,4
BASE GASKET THICKNESS 0,5
THICKNESS (IN STEEL)
Specification
HEAD GASKET THICKNESS (steel)
CYLINDER HEIGHT
MEASUREMENT 0,20 ± 0,05
MEASUREMENT 0,30 ± 0,05
Desc./Quantity
0.3 ± 0.05
57,15 ± 0,05
BASE GASKET THICKNESS 0,4
BASE GASKET THICKNESS 0,5
Products
TABLE OF RECOMMENDED PRODUCTS
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
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 seat- Lithium soap and zinc oxide grease NLGI
ings for swinging arms and contact sur2; ISO-L-XBCIB2
face of driven pulley spring (only pulley
side)
Grease for brake levers, throttle
White calcium complex soap-based
spray grease with NLGI 2; ISO-L-XBCIB2
CHAR - 15
INDEX OF TOPICS
TOOLING
TOOL
ET4 50
Tooling
TOOLING
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
TOOL - 17
ET4 50
Tooling
TOOL - 18
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
ET4 50
Tooling
Stores code
020288Y
Description
Fork to assemble piston on cylinder
020291y
Valves assembly/disassembly tool
020306Y
Punch for assembling valve seal rings
020329Y
MityVac vacuum-operated pump
020330Y
Stroboscopic light to check timing
020331Y
Digital multimeter
TOOL - 19
ET4 50
Tooling
TOOL - 20
Stores code
020332Y
Description
Digital rev counter
020333Y
Single battery charger
020334Y
Multiple battery charger
020335Y
Magnetic support for dial gauge
020340Y
Flywheel and transmission oil seals fitting
punch
020358Y
37x40-mm adaptor
ET4 50
Tooling
Stores code
020359Y
Description
42x47-mm adaptor
020360Y
Adaptor 52 x 55 mm
020362Y
12 mm guide
020363Y
20 mm guide
020364Y
25-mm guide
020376Y
Adaptor handle
TOOL - 21
ET4 50
Tooling
TOOL - 22
Stores code
020431Y
Description
Valve oil seal extractor
020432Y
Tool to fit the start-up sector spring
020439Y
17 mm guide
020444Y
020448Y
Test probe removal / fitting tool
Pin lock fitting tool
020449Y
Piston position check support
020450Y
Camshaft fitting/removal tool
020451Y
Drive pulley stop wrench
ET4 50
Tooling
Stores code
020452Y
Description
Tube for removing and refitting the driven
pulley shaft
020456Y
Ø 24 mm adaptor
020565Y
Flywheel lock calliper spanner
494929Y
Exhaust fumes analyser
TOOL - 23
INDEX OF TOPICS
MAINTENANCE
MAIN
ET4 50
Maintenance
Maintenance chart
AT 1000 KM OR 4 MONTHS
80'
Action
Hub oil - change
Valve clearance - check
Idle speed (*) - adjustment
Throttle lever - adjustment
Steering - adjustment
Brake control levers - greasing
Brake pads - check condition and wear
Brake fluid level - check
Safety locks - check
Electrical system and battery - check
Tyre pressure - check
Vehicle and brake test - road test
Emergency blockings (°) - Check
(*) Refer to rules «Adjusting the idle speed»
(°) Refer to predelivery operations
AT 6000 KM OR 12 MONTHS, 18000 KM OR 36 MONTHS, 30000 KM, AT 42000 KM, AT
54000 KM AND AT 66000 KM
70'
Action
Engine oil - replacement
Hub oil level - check
Oil filter (net filter) - clean
Variable speed rollers - check or replacement
Brake pads - check condition and wear
Brake fluid level - check
Electrical system and battery - check
Tyres condition and wear - Check
Tyre pressure - check
Vehicle and brake test - road test
AT 12000 OR 24 MONTHS AND AT 60000 KM
125'
Action
Engine oil - replacement
Hub oil level - check
Spark plug / electrode gap - check / replacement
Air filter - clean
Oil filter (net filter) - clean
Idle speed (*) - adjustment
Throttle lever - adjustment
Variable speed rollers - check or replacement
Driving belt - replacement
Odometer gear - greasing
Steering - adjustment
Brake control levers - greasing
Brake pads - check condition and wear
Brake fluid level - check
Transmission elements - lubrication
Emergency blockings (°) - Check
Suspensions - check
Electrical system and battery - check
Headlight - adjustment
Tyres condition and wear - Check
Tyre pressure - check
Vehicle and brake test - road test
MAIN - 25
ET4 50
Maintenance
* Refer to rules
(°) Refer to predelivery operations
AT 24000 KM OR 48000 KM
160'
Action
Engine oil - replacement
Hub oil level - replacement
Spark plug / electrode gap - check / replacement
Air filter - clean
Oil filter (net filter) - clean
Valve clearance - check
Idle speed (*) - adjustment
Throttle lever - adjustment
Variable speed rollers - check or replacement
Driving belt - replacement
Cylinder ventilation system - check
Odometer gear - greasing
Steering - adjustment
Brake control levers - greasing
Brake pads - check condition and wear
Brake fluid level - check
Transmission elements - lubrication
Emergency blockings (°) - Check
Suspensions - check
Electrical system and battery - check
Headlight - adjustment
Tyres condition and wear - Check
Tyre pressure - check
Vehicle and brake test - road test
* Refer to rules
(°) Refer to predelivery operations
AT 36000 KM
175'
Action
Engine oil - replacement
Hub oil level - check
Spark plug / electrode gap - check / replacement
Air filter - clean
Oil filter (net filter) - clean
Idle speed (*) - adjustment
Throttle lever - adjustment
Variable speed rollers - check or replacement
Driving belt - replacement
Odometer gear - greasing
Steering - adjustment
Brake control levers - greasing
Brake pads - check condition and wear
Brake fluid hoses - replacement
Brake fluid level - check
Transmission elements - lubrication
Emergency blockings (°) - Check
Suspensions - check
Electrical system and battery - check
Headlight - adjustment
Tyres condition and wear - Check
Tyre pressure - check
Vehicle and brake test - road test
* Refer to rules
(°) Refer to predelivery operations
AT 72000 KM
210'
MAIN - 26
ET4 50
Maintenance
Action
Engine oil - replacement
Hub oil level - replacement
Spark plug / electrode gap - check / replacement
Air filter - clean
Oil filter (net filter) - clean
Valve clearance - check
Idle speed (*) - adjustment
Throttle lever - adjustment
Variable speed rollers - check or replacement
Driving belt - replacement
Cylinder ventilation system - check
Odometer gear - greasing
Steering - adjustment
Brake control levers - greasing
Brake pads - check condition and wear
Brake fluid hoses - replacement
Brake fluid level - check
Transmission elements - lubrication
Emergency blockings (°) - Check
Suspensions - check
Electrical system and battery - check
Headlight - adjustment
Tyres condition and wear - Check
Tyre pressure - check
Vehicle and brake test - road test
* Refer to rules
(°) Refer to predelivery operations
EVERY 3,000 KM
10'
Action
Engine oil - level check/ top-up
EVERY 2 YEARS
Action
Brake fluid - change
MAIN - 27
Maintenance
ET4 50
Carburettor
- Disassemble the carburettor in its parts, wash all
of them with solvent, dry all body grooves with
compressed air to ensure adequate cleaning.
- Check carefully that the parts are in good condition.
-The throttle valve should move freely in the
chamber. Replace 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. Tank - 9. Starter device - 10. Vacuum valve - 11. Cover - 12. Minimum jet.
Checking the spark advance
The vehicle is provided with a variable spark advance electronic device. Two reference marks for the
timing can be found on the flywheel cover as to find out with more precision the reference mark on the
fan. To check, use a stroboscopic gun Tecnotest 130/P or similar type. Start the engine and let it run
at 1900 revs/min, act on the phase shifter to align the reference mark on the flywheel fan in between
the two reference marks on the casing; at the same time, read the spark advance value on the stroboscopic gun display. The value should be 10°.
Repeat the above operation with engine running at 5000-6000 revs/min, spark advance should be 26°.
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.
N.B.
WHEN THE INDUCTION CLAMP READS THE SIGNAL CORRECTLY, A READING CAN BE CARRIED OUT AT OVER 6000 RPM.
MAIN - 28
ET4 50
Maintenance
RPM LIMITER
Specification
1 spark out of 7
1 spark out of 3
Suppression of all sparks
Desc./Quantity
8200 Revs/min
8300 Revs/min
8500 Revs/min
Spark plug
-Disconnect the cap and remove the spark plug.
-Inspect the plug and if the insulator is chipped or
damaged, renew it.
-Measure the spark plug gap with a feeler gauge.
If necessary adjust the gap by bending the outer
electrode.
-Make sure the washer is in good condition.
-Fit the spark plug, screwing it in first by hand and
then tighten it to the prescribed torque with a plug
spanner.
Characteristic
Electrode gap
0.7 ÷ 0.8 mm
Spark plug
Champion RG 4 PHP
MAIN - 29
Maintenance
Champion RG 4 HC
Locking torques (N*m)
Spark plug 10 ÷ 15 Nm
Hub oil
Replacement
-Remove the oil filler plug.
-Unscrew the drain plug (A) shown in the figure
and allow the oil to drain out.
-Retighten the drain plug and fill the hub with oil
(about 80 cc).
-Check the level by referring to the min. and max.
notches. Carry out the check after placing the vehicle on its stand and removing the cap/dipstick
from the fully tightened position.
Recommended products
AGIP ROTRA 80W-90 rear oil hub
SAE 80W/90 Oil that exceeds the requirements of
API GL3 specifications
Air filter
After removing the lower part of the left-hand side
cover, unscrew the four fixing screws and the two
knobs (which are exposed by overturning the saddle and removing the helmet compartment), remove the filter cover and then pull out the filter
cartridge.
Cleaning:
-Wash the filter with soap and water.
-Dry with a clean cloth without wringing and with
compressed air.
-Soak with a 50% fuel-oil mixture.
-Let the filter cartridge drip and then squeeze it
between the hands without wringing.
CAUTION
MAIN - 30
ET4 50
ET4 50
Maintenance
NEVER RUN THE ENGINE WITHOUT THE AIR FILTER,
THIS WOULD RESULT IN AN EXCESSIVE WEAR OF THE
PISTON AND CYLINDER.
Engine oil
Replacement
-Loosen the oil filler plug.
-Unscrew the gauze strainer drain plug on the flywheel side and allow the oil to drain completely.
-Retighten the drain plug and pour in approximately 600-650 cc of oil.
Check
- Put the vehicle on the stand on level ground (cold
engine).
- Check that the oil level is between the MIN and
MAX marks on the sight.
- The MAX reference mark corresponds to approximately 850 cc of oil in the engine.
- If the oil level is near or below the MIN mark, top
up by adding fresh oil, taking care to never 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
MAIN - 31
Maintenance
CO check
- This check can be required when engine operation is irregular or while adjusting the slow running.
- The test must be carried out after carefully washing all carburettor components and making sure
that the air filter is clean and the spark plug is in
good condition.
1) Warm up the engine by riding at a speed of approximately 50 km/h for ~ 5 minutes. This will allow
the automatic starting device to cut out its circuit.
2) Switch off the engine for the minimum time required to perform steps 3) and 4).
3) Fit an extension tube ~ 50 cm in length to the
exhaust gas outlet on the silencer.
4) Take special care in ensuring the seal between
the silencer and the tube. Insert the exhaust gas
analyser probe into the tube.
5) Connect the multimeter thermometer to the
sump using an oil filler plug specially prepared for
the insertion of the probe.
6) Start the engine and, before proceeding to tune
up the idle speed, ensure that the oil temperature
is 70-80° C.
7) Allow the idle speed to stabilize for about a minute.
8) Without opening the throttle and using the
specially designed flow screw, adjust the speed of
the engine to 1,650 ± 50 rpm.
9) Adjust the flow screw until the «CO» percentage
is 3.8 ± 0.7 percent.
10) Slowly rotate the throttle twist grip until the
engine reaches a speed of 4,000 rpm, then close
the throttle again. Check that the idle speed is the
same as specified above. If not, repeat the procedure from step 3).
Specific tooling
020332Y Digital rev counter
MAIN - 32
ET4 50
ET4 50
Maintenance
494929Y Exhaust fumes analyser
020331Y Digital multimeter
MAIN - 33
INDEX OF TOPICS
TROUBLESHOOTING
TROUBL
ET4 50
Troubleshooting
Engine
Poor performance
POOR PERFORMANCE
Possible Cause
Air filter clogged 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
Timing failure or timing system parts worn
Muffler obstructed
Fuel filter on vacuum operated cock blocked
Wrong valve adjustment
Valve seat distorted
Worn cylinder, Worn or broken piston rings
Operation
Disassemble, wash sponge with water and shampoo and immerse in a mixture of 50% petrol and Selenia Air Filter oil. Let
it drip. Wring out without squeezing it and then refit
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
Reset timing phase or replace any worn parts (refer to 4-stroke
50 cc engine 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 rpms 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
STARTING PROBLEMS
Possible Cause
Defective spark plug or with incorrect electrode gap
Battery flat
- Engine flooded.
Vacuum operated cock failure
Failing automatic starter on the carburettor
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 up keeping the throttle fully open alternating approximately five seconds of turning it with five seconds still. 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
Check the electrical wiring and mechanical movement, replace
if necessary.
TROUBL - 35
ET4 50
Troubleshooting
Possible Cause
Wrong ignition advance
Incorrect valve sealing or valve adjustment
Starting rpm too low. Starter motor faulty.
Altered fuel characteristics
Carburettor nozzles clogged or dirty
Operation
Check flywheel keying on the crankshaft, replace control unit if
necessary
Inspect the head and/or restore the correct clearance
Check starting motor.
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 TENDS TO CUT OUT AT FULL THROTTLE
Possible Cause
Maximum jet clogged
Water or condensate in the carburettor tank
Incorrect ignition advance
Air filter blocked or dirty.
Incorrect float level
Fuel supply pipes choked or clogged
Tank breather hole obstructed
Level in tank too low
Operation
Remove the carburettor, wash with solvent and dry with compressed air
Remove the tank, 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 tank (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 tank aeration
Restore the correct level in the tank (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 TENDS TO STOP WHEN IDLING
Possible Cause
Air calibrated holes in carburettor blocked
Defective floating valve
Level in tank too high
Automatic choke stays activated
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 tank (the float must be parallel
to the upper cover contact plane, that is the throttle valve membrane cover)
Check that the piston slides freely and that fuel is supplied to
the automatic choke. Renew if necessary
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
High fuel consumption
EXCESSIVE FUEL CONSUMPTION
Possible Cause
Air filter blocked or dirty.
TROUBL - 36
Operation
Dismantle the sponge, wash with water and shampoo, then
soak it in a mixture of 50% petrol and 50% of specific oil (Se-
ET4 50
Troubleshooting
Possible Cause
Operation
lenia 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 tank
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 contact surface with the casing is mainly in the
centre with equivalent characteristics on the three masses.
Check that the clutch casing is not scored or worn in an anomalous way
Insufficient braking
INEFFICIENT BRAKING
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 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 sliding of pistons
Brake disc or drum deformed
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
Electrical system
TROUBL - 37
ET4 50
Troubleshooting
Battery
BATTERY
Possible Cause
Operation
This device requires the most assiduous surveillance and the This device requires the most assiduous surveillance and the
most diligent maintenance.
most diligent maintenance. If the vehicle is not used for some
time (1 month or more) the battery needs to be recharged periodically. The battery tends to exhaust its power supply in five
to six 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 EQUIPMENT FAILURE
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 in turning the steering continue even after making the
above adjustments, check the seats on 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 backlash
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
SUSPENSION NOISY
Possible Cause
Noisy suspension
TROUBL - 38
Operation
If the front suspension is noisy, check: that the front shock absorber works properly and the ball bearings are good condition.
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
ET4 50
Troubleshooting
Suspension oil leakage
OIL LEAKAGE FROM SUSPENSION
Possible Cause
Oil leakage from suspension
Operation
Replace the damper.
TROUBL - 39
INDEX OF TOPICS
ELECTRICAL SYSTEM
ELE SYS
ET4 50
Electrical system
ELECTRICAL EQUIPMENT
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
Specification
Horn
Headlight bulb
Parking light bulb
Key switch
Front brake stop button
Light switch
Turn indicator switch
Horn button
Light switch
Starter button
Speedometer with fuel gauge and warning lights 12V-1.2W reserve fuel warning light bulb, 2 x 12V-2W
turn indicator warning light bulbs, 12V-1.2W high beam
warning light bulb, 12V-1.2W instrument lighting bulb,
12V-1.2W lights-on warning light bulb.
Rear stop light switch
Starter remote control
Voltage regulator
Battery
Rear turn indicator bulbs
Front direction indicator lights
Brake light button on rear brake
Magneto flywheel
Pick - up
Automatic starter
Starter motor
Fuel level sending unit
Fuse
Headlight assembly
Rear light assembly
Electronic ignition device
Desc./Quantity
12V-35/35W
12V-5W
12V - 9Ah
Two, 12V-10W, spherical
N° 2, 12V-10W, spherical
12V-21/5W
10 A
Wiring colour chart:
ELE SYS - 41
ET4 50
Electrical system
B=White - Bl=Blue - G=Yellow - M=Brown - N=Black - BV=White-Green - GN=Yellow-Black - Gr=Grey
- Rs=Pink - R=Red - Vi=Purple - V=Green - VN=Green-Black - BN=White-Black - BBl=White-Blue GV=Yellow-Green - Ar=Orange - GrBl=Grey-Blue - GrN=Grey-Black - BR=White-Red - RN=Red-Black
- BlN=Blue-Black.
CAUTION
SHOULD ANY INTERVENTIONS TO THE ELECTRIC SYSTEM BE REQUIRED, MAKE SURE THAT
THE LEADS TO THE ELECTRONIC IGNITION DEVICE ARE PROPERLY CONNECTED ACCORDING TO POLARITY AND TO THE LEAD COLOURS.
Conceptual diagrams
Ignition
IGNITION SECTION
1
2
3
4
5
6
7
ELE SYS - 42
Specification
Electronic ignition device
Key switch contacts
Voltage regulator
Magneto flywheel
Pick - up
Main fuse
Battery
Desc./Quantity
10A
12V - 9Ah
ET4 50
Electrical system
Headlights and automatic starter section
LIGHTS
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
Specification
Voltage regulator
Main fuse
Magneto flywheel
Key switch contacts
Headlight bulb
High-beam warning light
Parking light bulb
2 Instrument lighting bulbs
1 Instrument panel lighting bulb
Lights-on warning, 1 light bulb
Rear light bulb, 1 light bulb
Electronic ignition device
Automatic starter
Light switch
Light switch
Battery
Desc./Quantity
10A
12V-35/35W
12V - 1.2W
12V- 5W
12V- 1,2W
12V- 2W
12V-1,2W
12V-5/21W
12V - 9Ah
ELE SYS - 43
ET4 50
Electrical system
Battery recharge and starting
BATTERY RECHARGE AND STARTING
1
2
3
4
5
6
7
8
9
10
ELE SYS - 44
Specification
Magneto flywheel
Starter motor
Main fuse
Battery
Key switch contacts
Voltage regulator
Electronic ignition device
Starter remote control
Starter button
Front and rear brake light button
Desc./Quantity
10A
12V - 9Ah
ET4 50
Electrical system
Level indicators and enable signals section
SAFETY SWITCHES
1
2
3
4
5
6
7
8
Specification
Voltage regulator
Fuel gauge
Fuel level sending unit
Low fuel warning light
Front and rear brake light button
Horn
Horn button
Brake light filament
Desc./Quantity
12V
12V-21W
ELE SYS - 45
ET4 50
Electrical system
Turn signal lights
TURN SIGNAL LIGHTS
1
2
3
4
ELE SYS - 46
Specification
Turn indicator switch
Voltage regulator
4 Turn indicator bulbs
Two (2) turn signal warning light bulbs
Desc./Quantity
12V-10W
12V - 2W
ET4 50
Electrical system
Instruments and warning lights control board
WARNING LIGHTS AND GAUGES PANEL
1
2
3
4
5
6
7
8
9
Specification
Left turn indicator warning light
High-beam warning light
Fuel Level indicator
Instrument panel lighting bulb
Headlight warning light
Reserve fuel light
Right turn indicator warning light
Dashboard light bulbs
Available warning light
Desc./Quantity
12V - 2W
12V - 1.2W
12V-1,2W
12V 1.2W
12V-1,2W
12V - 2W
12V-2W
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.
ELE SYS - 47
ET4 50
Electrical system
If faulty or failed operation persists, conduct the
following checks on the generator and on the stator components:
After a visual inspection of the electrical connections, it is possible to perform measurements on
the stator winding and pick-up (see table), using
the specific multimeter.
If, during the checks on the charge coil and the
pick-up, anomalies are found, replace the stator
and other faulty parts.
Disconnect the connector on the flywheel housing
and measure the resistance between each of the
two contacts and the earth.
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
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 irreparably damaged.
ELE SYS - 48
Desc./Quantity
~1Ω
ET4 50
Electrical system
Voltage regulator check
The malfunctioning of the voltage regulator might cause the following problems depending on the type
of fault:
1) Bulbs burnt out (regulator in short circuit).
2) The lighting and electrical starter system do not work (regulator interrupted).
3) Battery fails to charge
4) Turn indicators failure
The regulator is provided with earth supplied from the electrical equipment, therefore the regulator body
does not supply earth to the internal circuits. Check the insulation between each terminal of the regulator
and its body, using the specific tester.
1) BURSTING LIGHT BULBS
Replace the voltage regulator as this is definitely
faulty.
2) HEADLIGHTS AND CHOKE NOT-OPERATIONAL
In order to leave the AC free from absorptions, so
to carry out voltage checks, please proceed as follows. Remove the handlebar covers. Detach the
connections from the headlight and the 5 PIN connector from the dashboard. Remove the taillight
bulb. Remove the automatic choke connector from
the system.
Access the voltage regulator, start the engine and
let it run at idle.
Insert the positive terminal from the tester (setting
the tester on AC mode) on terminal no. 1 (yellowblack wire) and the negative terminal on terminal
no. 2 (black wire); check for voltage (see figure).
If voltage is present, check the wiring from the
headlight to the voltage regulator, and the operation of the light switch.
If no voltage is found, put the negative terminal to
earth; if this provides voltage readings, check the
earth wire (terminal no. 2) on the regulator (black
wire); otherwise, replace the regulator as certainly
faulty.
ELE SYS - 49
Electrical system
As a last test it is possible to check the output voltage from the stator:
-Detach the regulator connector and interpose the
tester in AC mode, between the Gray-Blue wire (4)
and earth (see figure).
-The voltage output at 2,000 rpm must be approx.
25 - 35V
If this test also gives no voltage, replace the regulator as certainly faulty.
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 DOES NOT RECHARGE
The fault in the DC section of the voltage regulator
may cause, depending on the type of failure, the
following faults:
a) Bursting of protection fuse due to excessively high voltage (regulator short-circuited)
and resulting in the battery not recharging.
b) Battery not recharging (regulator circuit interrupted).
Interventions
a) Bursting of protection fuse (regulator shortcircuited).
Check the wiring running from the fuse to the ignition key-switch is not damaged, as this may create a short-circuit with earth (thus excluding
possible regulator failures); if the protection fuse
bursts only after the ignition key-switch is turned
to "ON", and with the regulator connector detached, it is then necessary to check the wirings and
systems downstream the key-switch are not shortcircuited with earth.
ELE SYS - 50
ET4 50
ET4 50
Electrical system
Proceed by measuring the resistance between
contacts 3 (White) and 2 (Black) from the voltage
regulator (with the connector detached).
If the reading differs excessively from the figures
shown, replace the regulator as short-circuited.
b) Battery not recharging (regulator circuit interrupted).
To check for the presence of faults on the recharging section of the voltage regulator, it is necessary
to initially operate on the battery, using two testers
(one for voltages and one for currents), as shown
in the second figure, and follow the operations given below:
Start the engine (connecting, temporarily, the red
wire to the positive terminal of the battery, so to
avoid damaging the instrument measuring the current).
Check the voltage at idle is at least 13V (charged
battery) and the recharge current is 1.5 - 2A with
the lighting system and the choke device excluded, as described in the chapter "CHECKING THE
VOLTAGE REGULATOR".
As the engine speed increases, so do the recharge
current and voltage, and at speeds above 4,000
rpm, a recharging current of approx. 4.5A must be
observed; reactivating the lighting system and
choke device, and operating the stop light and
horn, current values of ≥ 5A may be found, with
voltage readings of 14 - 14.5V (regulator threshold
voltage).
If the readings do not match the above figures,
replace the regulator; otherwise check wiring
and connections.
Electric characteristic
Resistance of voltage regulator
~ 8 MΩ
ELE SYS - 51
Electrical system
Turn signals system check
4) TURN INDICATORS NOT WORKING
If the turn indicators do not work, do the following:
- Disconnect the regulator connection and insert
the multimeter probes between the white cable (3)
and the black one (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 white cable and
the earth; if there is no voltage even after this operation, check the wiring and the contacts of the
key switch and the battery. If voltage in the battery
is detected (black cable), check the regulator earth
wiring.
- If the above tests have positive results, jump the
contacts 5 (blue/black) and 3 (white) on the connector, set the key switch to ON and the turn
indicator switch left and right to see when the lights
are steadily on (as they are powered directly from
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
ELE SYS - 52
ET4 50
ET4 50
Electrical system
Sealed battery
INSTRUCTIONS FOR REFRESHING THE
STOCK CHARGE OF AN OPEN CIRCUIT
1) Voltage check
Before installing the battery on the vehicle, check
the open circuit voltage with a normal tester.
- If the voltage exceeds 12.60 V, the battery may
be installed without any renewal recharge.
- If voltage is below 12.60 V, a renewal recharge
is required as explained in 2).
2) Constant voltage battery charge mode
-Constant voltage equal to 14.40÷14.70V
-Initial charge voltage equal to 0.3÷0.5 for nominal
capacity
-Duration of the charge: 10 to 12 h recommended
Minimum 6 h
Maximum 24 h
3) Constant current battery charge mode
-Charge current equal to 1/10 of the nominal capacity of the battery
-Duration of the charge: 5 h
WARNING
-WHEN THE BATTERY IS REALLY FLAT (WELL BELOW
12.6V) IT MIGHT BE THAT 5 HOURS OF RECHARGING ARE
NOT ENOUGH TO ACHIEVE OPTIMAL PERFORMANCE.
IN THESE CONDITIONS IT IS HOWEVER ESSENTIAL NOT
TO EXCEED EIGHT HOURS OF CONTINUOUS RECHARGING SO AS NOT TO DAMAGE THE BATTERY ITSELF.
1 Hold the vertical tube
2 Look at the level
3 The float must be freed
Dry-charge battery
The battery is an electrical device which requires careful monitoring and diligent maintenance. The
maintenance rules are:
1) Check the level of the electrolyte
The electrolyte level must be checked frequently and must reach the upper level. Only use distilled
water, to restore this level.
If it is necessary to add water too frequently, check the vehicle's electrical system: the battery works
overcharged and is subject to quick wear.
ELE SYS - 53
Electrical system
ET4 50
2)Load status check
After restoring the electrolyte level, check its density using an appropriate densitometer (see the figure).
When the battery is charged, you should detect a density of 30 to 32 Bé corresponding to a specific
weight of 1.26 to 1.28 at a temperature of no lower than 15° C.
A density reading of less than 20° Bé indicates that the battery is completely flat and it must therefore
be recharged.
After charging the battery, check each element electrolyte level and density. If the scooter is not used
for a given time (1 month or more) it will be necessary to periodically recharge the battery.
The battery runs down completely in the course of three months.
If it is necessary to refit the battery in the vehicle, be careful not to reverse the connections, remembering
that the earth wire (black) marked (-) must be connected to the - negative terminal while the other two
red wires marked (+) must be connected to the terminal marked with the + positive sign.
Regular bench charging must be carried out with the specific battery charger, (single) or (multiple),
setting the battery charger selector to the type of battery to be recharged. Connections to the power
supply source must be implemented by connecting the corresponding poles (+ to+ and - to -).
4) Cleaning the battery
The battery should always be kept clean, especially on its top side, and the terminals should be coated
with Vaseline.
WARNING
- Before recharging the battery, remove the plugs of each cell. Keep the battery away from naked flames
or sparks when charging.
Remove the battery from the vehicle removing the negative clamp first.
CAUTION
NEVER USE FUSES WITH A CAPACITY HIGHER THAN THAT RECOMMENDED.
USING A FUSE OF UNSUITABLE RATING MAY SERIOUSLY DAMAGE THE VEHICLE OR EVEN
CAUSE A FIRE.
CAUTION
DRINKING WATER CONTAINS MINERALS THAT CAN BE EXTREMELY HARMFUL TO THE BATTERY: USE DISTILLED WATER ONLY.
CAUTION
TO ENSURE MAXIMUM PERFORMANCE THE BATTERY MUST BE CHARGED BEFORE USE.
INADEQUATE CHARGING OF THE BATTERY WITH A LOW ELECTROLYTE LEVEL BEFORE IT
IS FIRST USED SHORTENS THE LIFE OF THE BATTERY.
Specific tooling
020333Y Single battery charger
020334Y Multiple battery charger
1)- Remove the short closed tube and the caps, then pour sulphuric acid into the cells using the type
specified for batteries, with a specific gravity of 1.26, corresponding to 30° Bé, at a minimum temperature
of 15°C until the upper level is reached.
2) - Leave to rest for at least 2 hours; then, restore the level with sulphuric acid.
ELE SYS - 54
ET4 50
Electrical system
3)- Within the following 24 hours, recharge with the specific battery charger (single) or (multiple) at a
density of about 1/10 of the battery nominal capacity and until the acid density is about 1.27, corresponding to 31º Bé, and these values are stabilised.
4) - Once the charge is over, level the acid (by adding distilled water). Close and clean carefully.
5)- Once the above operations have been performed, install the battery in the vehicle ensuring the
connections between the wiring and the battery terminals are correct.
WARNING
- ONCE THE BATTERY HAS BEEN INSTALLED IN THE VEHICLE IT IS NECESSARY TO REPLACE
THE SHORT TUBE (WITH CLOSED END) NEAR THE + POSITIVE TERMINAL WITH THE CORRESPONDING LONG TUBE (WITH OPEN END), THAT YOU FIND FITTED TO THE VEHICLE, TO
ENSURE THAT THE GASES THAT FORM CAN ESCAPE PROPERLY.
Specific tooling
020333Y Single battery charger
020334Y Multiple battery charger
WARNING
- Battery electrolyte is toxic and it may cause serious burns. It contains sulphuric acid. Avoid contact
with eyes, skin and clothing. In case of contact with eyes or skin, flush abundantly with water for about
15 minutes and seek immediate medical attention.
In the event of accidental ingestion of the fluid, immediately drink large quantities of water or milk. Follow
with milk of magnesia, beaten egg or vegetable oil. Seek immediate medical attention
Batteries produce explosive gases; keep clear of free flames, sparks or cigarettes; ventilate the area
when recharging the battery indoors.
Always protect your eyes when working close to batteries.
Keep out of the reach of children.
ELE SYS - 55
INDEX OF TOPICS
ENGINE FROM VEHICLE
ENG VE
ET4 50
Engine from vehicle
Exhaust assy. Removal
- Remove the 2 fixing nuts from the manifold to the
head
- Unscrew 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
Disassembling engine from frame
-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 - 57
INDEX OF TOPICS
ENGINE
ENG
ET4 50
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 - 59
Engine
ET4 50
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 DRIVE
PULLEY MOUNTED.
Specific tooling
020565Y Flywheel lock calliper spanner
ENG - 60
ET4 50
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 - 61
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 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 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 - 62
ET4 50
ET4 50
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 - 63
Engine
ET4 50
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 tone wheel
revolving ring
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 gr. 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 tone wheel revolving ring
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 - 64
ET4 50
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 - 65
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 - 66
ET4 50
ET4 50
Engine
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 - 67
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 - 68
ET4 50
ET4 50
Engine
Refitting the transmission cover
- Check the following for wear: toothed section,
toothed section shaft, cover seat bushing, pinion
shaft and it 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 - 69
Engine
Removing the hub cover
- Drain the rear hub oil
- Remove driven pulley
- Remove the rear brake shoes
- Remove the 5 screws fixing the cover to the
crankcase
- Remove the cover with the wheel axle and pull it
out
- Remove the intermediate gear with the appropriate shim washers
Removing the wheel axle bearings
- Remove the oil seal and the seeger ring.
- Fix the hub cover properly to avoid damaging the
sealing surface with the housing
- Remove the wheel axle bearing using the specific
tool
Specific tooling
020363Y 20 mm guide
020376Y Adaptor handle
020477Y Adaptor 37 mm
ENG - 70
ET4 50
ET4 50
Engine
Removing the driven pulley shaft bearing
- Remove the seeger ring
- Heat the engine crankcase but do not direct the
hot air towards the bearing
- Extract the driven pulley shaft together with the
bearing with a few mallet blows
- Remove the bearing off the driven pulley shaft
using the specific tool and a press
N.B.
USE THE SPECIFIC TOOL ON THE SIDE WITH THE SMALLER INTERNAL DIAMETER
Specific tooling
020452Y Tube for removing and refitting the
driven pulley shaft
ENG - 71
Engine
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.
Refitting the wheel axle bearing
- Support the hub cover on a wooden surface
- Heat up the hub cover using the thermal gun.
- Preassemble the bearing on the specific punch
using grease and then insert the bearing in its
seating
- Refit the seeger ring and the oil seal using the 42
x 47 mm adaptor
N.B.
POSITION THE OIL SEAL WITH THE SEALING LIP FACING
THE HUB INTERNAL SIDE
Specific tooling
020150Y Air heater support
020151Y Air heater
020376Y Adaptor handle
ENG - 72
ET4 50
ET4 50
Engine
020363Y 20 mm guide
020359Y 42x47-mm adaptor
Refitting the hub bearings
- Remove the wheel axle on the cover and pay attention not to damage the sealing lip of the oil seal
- Apply a thin layer of grease on the two shim
washers of the intermediate gear and fit one on the
cap so that it does not interfere with the wheel axle
gear when placing the transmission shaft
Refitting the ub cover
- Apply product recommended for surfaces on the
hub cap and refit cap on the crankcase
- Fit 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.
Recommended products
Loctite 510 Liquid sealant
ENG - 73
Engine
Gasket
Locking torques (N*m)
hub cap screws 24 - 26
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 - 74
ET4 50
ET4 50
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.
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
ENG - 75
Engine
Removing the starter motor
- Unscrew the screw on the power positive contact
and disconnect the cable
- Unscrew the 2 screws fixing the starter motor to
the crankcase and recover the power wiring.
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
ENG - 76
ET4 50
ET4 50
Engine
Inspecting the flywheel components
- Check that the flywheel internal magnets are in
good conditions.
- Check that the flywheel riveted joints are correctly
tightened.
- 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.
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.
ENG - 77
Engine
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
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 motor screws 11 ÷ 13
Cylinder assy. and timing system
ENG - 78
ET4 50
ET4 50
Engine
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
Removal
Removing the driving pulley
ENG - 79
Engine
Removing the cam shaft
- Remove the bearing clamping screw indicated in
the figure.
- 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
- Pull out the rocking lever bolt operating on the
flywheel hole and remove the rocking levers at the
same time.
N.B.
MARK THE ASSEMBLY POSITION OF THE ROCKING LEVERS IN ORDER TO AVOID MISPLACING THE INTAKE AND
DISCHARGE ENDS.
ENG - 80
ET4 50
ET4 50
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 element
shown in the figure, remove the cotters, the plates
and the spring between the valves.
- Remove the oil seals with the appropriate tool.
- Remove the lower spring supports.
Specific tooling
020431Y Valve oil seal extractor
ENG - 81
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 - 82
ET4 50
ET4 50
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 pin
12.990 mm
Inspecting the piston
- Calculate the piston pin coupling clearance.
Fitting clearance
Pin coupling clearance 13 +0.010+0.005mm 0.005 ÷
0.014 mm
- Measure the outside diameter of the piston, perpendicular to the gudgeon pin axis.
- Carry out the measurement at 27 from the piston crown as shown in the figure.
- Carefully clean the sealing rings housings with the aid of an old piston ring.
- Measure the coupling clearance between the sealing rings and the piston grooves using a thickness
gauge, as shown in the figure.
- If the clearances detected exceed the limits specified in the table, the piston and the piston rings should
be replaced.
PISTON
Name
Top piston ring
Middle piston ring
oil scraper
Description
Dimensions
0.030 ÷ 0.065 mm
0.020 ÷ 0.055 mm
0.040 ÷ 0.160 mm
Initials
Quantity
0.080 mm
0.070 mm
0.20 mm
ENG - 83
Engine
ET4 50
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
- The cylinder rectifying operation should be carried out with a surfacing that respects the original
angle. at 120° crossed.
- The cylinder surface roughness should be of
R.A.= 0.30 ÷ 0.50.
- This is indispensable for a good seating of the
sealing rings, which in turn minimises oil consumption and guarantees optimum performance.
- The pistons are oversized due to cylinder rectification and are subdivided into two categories 1st
and 2nd with 0.2-0.4mm oversize. They are also
classified into 4 categories A-A, B-B, C-C, D-D.
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.
ENG - 84
ET4 50
Engine
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.
SEALING RINGS
Name
Top piston ring
Middle piston ring
oil scraper
Description
Dimensions
0.08 ÷ 0.20 mm
0.05 ÷ 0.20 mm
0.20 ÷ 0.70 mm
Initials
Quantity
0.35 mm
0.30 mm
0.80 mm
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
- 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.
ENG - 85
ET4 50
Engine
Choosing the gasket
This engine is manufactured with two different head gasket solutions:
- Fibre gasket drw. 969244 0.95 mm thick.
- Steel gasket drw. 969393 0.3 mm thick.
In order to guarantee an adequate compression ratio, the gaskets match cylinders with different heights:
- Fibre gaskets with cylinder 56.45 mm high
- Fibre gaskets with cylinder 57.15 mm high
In order to carry out the revision both gaskets should be present on the spare parts.
All pin-piston-cylinder units supplied with the spare parts present cylinders 57.15 mm high
- Provisionally fit the piston into the cylinder, without any base gasket.
- Fit a dial gauge on the specific tool, then rest both on a stop surface.
- Zero set the dial gauge on the stop surface. Keeping the zero position, assemble the tool on the cylinder
and lock it with 2 nuts as shown in the figure.
- Rotate the crankshaft until TDC (the inverted point of the dial gauge rotation)
- Measure piston protrusion compared with the head plane and determine the gasket thickness to be
used according to the table below. By correctly identifying the cylinder base gasket thickness, an adequate compression ratio is maintained.
- Remove the specific tool and the cylinder.
Characteristic
Standard compression ratio
C.R. 11.5 ÷ 12 ÷ 1
CYLINDER BASE GASKET THICKNESS
Specification
Cylinder height
Head gasket thickness (fibre)
Measure detected
Base gasket thickness
Measure detected
Base gasket thickness
Desc./Quantity
56.45 ± 0.05
0.95 ± 0.06
0.9 ± 0.05
0.4
1 ± 0.05
0.5
CYLINDER BASE GASKET THICKNESS
Specification
Cylinder height
Head gasket thickness (steel)
Measure detected
Base gasket thickness
Measure detected
Base gasket thickness
ENG - 86
Desc./Quantity
57.15 ± 0.05
0.3 ± 0.05
0.20 ± 0.05
0.4
0.30 ± 0.05
0.5
ET4 50
Engine
N.B.
MEASUREMENT "A" TO BE TAKEN IS A VALUE OF PISTON RE-ENTRY, IT INDICATES BY HOW
MUCH THE PLANE FORMED BY THE PISTON CROWN FALLS BELOW THE PLANE FORMED BY
THE TOP OF THE CYLINDER. THE FURTHER THE PISTON GETS INSIDE THE CYLINDER, THE
THINNER THE HEAD GASKET TO BE APPLIED SHOULD BE (TO RECOVER THE COMPRESSION
RATIO) AND VICE VERSA.
Characteristic
Shimming system to control the compression ratio
CR: 11.1 ÷ 12.9
PISTON PROTRUSION CHECK
Name
shimming_1
shimming_2
Measure A
0.05 ÷ 0.25
0.25 ÷ 0.40
Thickness
0.35
0.25
ENG - 87
ET4 50
Engine
Refitting 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.
SEALING RINGS
Name
Top piston
ring
Middle piston ring
oil scraper
ENG - 88
Descripti
on
Dimensio
ns
0.08 ÷
0.20 mm
0.05 ÷
0.20 mm
0.20 ÷
0.70 mm
Initials
Quantity
0.35 mm
0.30 mm
0.80 mm
ET4 50
Engine
- 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.
- Offset the ring gaps by 120° to each other 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.
Refitting the cylinder
- Fit the base gasket of the chosen thickness, previously determined.
- 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.
ENG - 89
ET4 50
Engine
The procedure is different from that indicated in the vehicle manuals:
Head nuts tightening (only for stud bolts replacement) 6÷7 N*m +90° + 90° + 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.
Characteristic
Maximum admitted unevenness: Head check
0.05 mm
HEAD CHECK
Specification
Standard diameter (mm) A
Standard diameter (mm) B
Standard diameter (mm) C
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.
ENG - 90
Desc./Quantity
Ø 32.015 ÷ 32.025 mm
Ø 16.0 ÷ 16.018
Ø 11.0 ÷ 11.018
ET4 50
Engine
- 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.
Inspecting the valve sealings
- Measure the width of the sealing surface on the
valve seats.
Characteristic
Sealing surface width: Intake
1.5 mm
Sealing surface width: Drainage
1.6 mm
- Insert the valves into the cylinder head.
- Test the 2 valves alternatively.
- 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 valve housings
- Remove any carbon formation from the valve
guides.
- Measure the inside diameter of each valve guide.
- Take the measurement at three different heights
in the rocker arm push direction.
Characteristic
Discharge guide: Standard diameter
5 +0+0.012mm
Discharge guide: Wear limit
5.022 mm
Intake guide: Standard diameter
ENG - 91
Engine
ET4 50
5 +0+0.012mm
Intake guide: Wear limit
5.022 mm
- If the width of the impression on the valve seat or the diameter of the valve guide exceed the specified
limits, replace the cylinder head.
- Check width of the impression on the valve seat «V»
Characteristic
Wear limits:
Max. 1.6 mm.
Inspecting the valves
- Measure the diameter of the valve stems in the
three positions indicated in the diagram.
- Calculate the clearance between the valve and
the valve guide.
Characteristic
Minimum diameter allowed: Intake
4.970 mm
Minimum admissible diameter drainage
4.960 mm
Fitting clearance
Standard clearance: Intake 0.015 ÷ 0.042 mm
Standard clearance: drainage 0.025 ÷ 0.052 mm
- Check that there are no signs of wear on the
contact surface with the articulated register terminal.
- If the sealing surface on the valves is wider than
the specified limit, damaged in one or more points
or curved, replace the valve with a new one.
Characteristic
Valve standard length: Intake
70.1 mm
Valve standard length: drainage
69.2 mm
Fitting clearance
Max. clearance allowed: Intake 0.052 mm Max.
clearance allowed: drainage 0.062 mm
- If the checks above give no failures, you can use the same valves. For best sealing results, it is
advisable to grind the valves. Grind the valves gently with a fine-grained lapping compound. During
ENG - 92
ET4 50
Engine
grinding, keep the cylinder head in a horizontal position. This will prevent the lapping compound residues from penetrating between the valve stem/guide coupling.
CAUTION
TO AVOID SCORING THE CONTACT 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.
Inspecting the springs and half-cones
- Check that the upper spring caps and the cotter
halves show no signs of abnormal wear.
Refitting the valves
- Lubricate the valve guides with graphite grease.
- Place the lower plates of the valve spring on the
head.
- Use the punch to fit the 2 sealing rings one at a
time.
Specific tooling
020306Y Punch for assembling valve seal
rings
- Fit the valves, the springs and the upper plates.
- Using the appropriate tool, compress the springs
and insert the cotters in their seats.
ENG - 93
ET4 50
Engine
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
- 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 - Intake:
25.935 mm
Standard height - Discharge:
25.935 mm
Fitting clearance
Maximum admissible axial clearance 0.5 mm
- Check there are no signs of scoring or wear on
the rocking lever bolt.
- Measure the diameter «A».
- Measure the internal diameter of each rocking
lever. level «B».
Check there are no signs of wear on the pad from
contact with the cam and on the jointed adjustment
plate.
- In case of anomalies, replace the damaged components.
Characteristic
ENG - 94
ET4 50
Engine
Minimum admissible diameter
Ø 10.970 mm
Maximum diameter allowed:
Ø 11.030 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.
- 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
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
- Loosen the rocking lever registers.
- Fit the pin, the intake rocking lever and the 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 the limit screw for the pin and the camshaft
with the washer indicated in the figure and tighten
it to the prescribed torque.
Locking torques (N*m)
Rocking lever axle and camshaft bearing
screw 3 ÷ 4 Nm
ENG - 95
Engine
- 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
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 on the camshaft.
- Fit the belleville washer so that the outer rim
touches the pulley.
ENG - 96
ET4 50
ET4 50
Engine
- 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)
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.
Characteristic
Recommended spark plug
NGK CR 9EB - CHAMPION RG 4HC
Electric characteristic
Electrode gap
0.7 ÷ 0.8 mm
Locking torques (N*m)
Timing chain tensioner screw 8 ÷ 10 Nm Timing chain tensioner central screw 5 - 6 Ignition spark
plug 10 ÷ 15 Nm
ENG - 97
Engine
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.
Locking torques (N*m)
Timing chain tensioner screws 8 ÷ 10 Nm
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.
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 starter motor
Removing the driven pulley
Removing the stator
Removal
Removing the cylinder - piston assy.
Removing the driving pulley
ENG - 98
ET4 50
ET4 50
Engine
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.
- Check the axial clearance on the connecting rod.
Fitting clearance
Connecting rod endfloat - standard clearance
0.15 ÷ 0.30 mm Connecting rod endfloat - standard
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
ENG - 99
Engine
- 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
Refitting the crankshaft bearings
- 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 - 100
ET4 50
ET4 50
Engine
- 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 Adaptor 52 x 55 mm
Inspecting the crankshaft alignment
To install the drive shaft on the support and to
measure the misalignment in the 4 points indicated
in 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 driving shaft.
Specific tooling
ENG - 101
Engine
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.
- 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
ENG - 102
ET4 50
ET4 50
Engine
Crankshaft oil seals
Removal
- 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).
- Extract the flywheel oil seal from the crankcase
being careful not to damage or score the crankcase.
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.
ENG - 103
Engine
- 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
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.
ENG - 104
ET4 50
ET4 50
Engine
- Remove the central screw and the belleville
washer
- Remove the chain with the crown gear.
- Remove the pinion of the crankshaft control.
- 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.
- 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
ENG - 105
Engine
- 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.
- 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
ENG - 106
ET4 50
ET4 50
Engine
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 cap «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
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 MITIVAC 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.
ENG - 107
Engine
- 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 gas tank.
- Remove the petrol delivery tube and the suction
tube.
- Loosen the clip and remove the tap.
- Clean the tank and the filter of the tap with a specific solvent.
- Refit the tap making sure that there is an O-Ring.
- Turn the tap to the direction it had before it was
removed and block the clip.
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.
ENG - 108
ET4 50
ET4 50
Engine
- Remove the protection, the bracket and the starter undoing the screw shown in the figure.
CAUTION
THE CARBURETTOR FEATURES AN ANTIVIBRATION
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 tank with the
gasket.
- Remove the tank components following the procedure below.
- Undo the 2 screws fixing the intake pump diaphragm cover.
ENG - 109
Engine
- 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.
-Remove the minimum nozzle.
ENG - 110
ET4 50
ET4 50
Engine
- 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 - 111
Engine
ET4 50
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 the 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 tank and the diaphragm are not dented.
-Check that the depression valve housing pipe is not scratched.
- Check that the throttle valve and the shaft do not show abnormal wear.
- Check that the plunger seat does not show abnormal wear.
- Replace the carburettor in case of irregularities.
N.B.
TO AVOID DAMAGES, DO NOT INTRODUCE METAL OBJECTS IN THE ADJUSTED SECTIONS.
ENG - 112
ET4 50
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 - 113
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 - 114
ET4 50
ET4 50
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 mm
ambient temperature
24° C
ENG - 115
Engine
- The starter should disconnect progressively by
means of electrical heating.
- Check the starter resistance when adjusted to the
ambient temperature.
Characteristic
ambient temperature
24° C
Electric characteristic
Automatic starter resistance
6Ω±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 - 116
ET4 50
ET4 50
Engine
- Insert rubber pipes for tank 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.
- Warm up the engine by running it at least 10 minutes at a speed as close as possible to the maximum one.
- Connect the vehicle to the exhaust fumes analyser inserting the probe into a sealed extension pipe
placed at the muffler exit end.
N.B.
THE EXTENSION TUBE IS INDISPENSABLE SO AS NOT
TO SEND POLLUTED EXHAUST FUMES TO THE AMBIENT
OXYGEN. IT IS ESSENTIAL TO USE AN EXHAUST FUMES
ANALYSER PREVIOUSLY HEATED AND PREPARED TO
GUARANTEE THE RESET OF THE READING OF GASES
AND THE CORRECT GAS CAPACITY. FAILURE TO RESPECT THESE REGULATIONS RESULTS IN INACCURATE
READINGS.
Characteristic
Pipe ideal length
ENG - 117
Engine
ET4 50
40 ÷ 50 cm
- 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
- 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 rev counter
Characteristic
Idle speed
about 1900/2000 rpm
- Adjust the flow screw until a percentage of carbon
monoxide (CO) is obtained. When the screw is
loosened the CO value rises (rich mix). Tightening
the screw decreases the CO (lean mix).
- If the adjustment of the flow screw causes a rpm
increase readjust the revs again and if necessary,
the flow screw to reach stable values.
Characteristic
CO adjustment
3,2% ± 0,5
- When the oil temperature, the numbers of revs and the percentage of carbon monoxide are respected
the idle carburetion is considered correct.
- Further information can be drawn from the analyser:
- carbon dioxide percentages (CO2), the percentage of carbon dioxide has an inverted course compared
to the percentage of (CO), values over 13% are considered correct.
- Non complying values indicate lack of tightness in the exhaust system.
- Unburned hydrocarbons (HC) are measured in parts per million (PPM). The HC value decreases while
the rpm increases; with the engine at idle it is normal to obtain 200 ÷ 400 PPM, these emission values
are deemed normal for an engine with a diagram of timing for motorcycles. Higher values can cause
ENG - 118
ET4 50
Engine
loss of engine blows as the mixture is too lean (low CO), ignition failure or, incorrect timing or a clogged
or unsealed exhaust valve.
If it is difficult to adjust CO values, check accurately:
- That the automatic starter is efficient.
- That the tapered pin-housing is efficient
- Tank level adjustments
ENG - 119
INDEX OF TOPICS
SUSPENSIONS
SUSP
ET4 50
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.
Front wheel hub overhaul
-Remove the needle bearing by driving it out from
the ball bearing side using a suitable drift.
-Drive out the ball bearing from the needle bearing
side.
-Fit the needle bearing by means of the specially
designed drift.
-Fit the ball bearing.
-Position the seal ring and the circlip.
CAUTION
BEFORE REFITTING, SMEAR THE PARTS WITH JOTA 3 FS
GREASE IN THE AREAS MARKED WITH AN ASTERISK.
Recommended products
AGIP GREASE MU3 Grease for odometer
transmission gear case
Soap-based lithium grease with NLGI 3; ISO-LXBCHA3, DIN K3K-20
SUSP - 121
Suspensions
-Loosen the central nut (see figure) to remove the
hub.
- Remove the brake calliper by removing the two
screws.
- Remove the split pin and the nut cap.
WARNING
-ALWAYS USE NEW SPLIT PINS FOR REFITTING.
-Slacken the brake calliper screw and the plate
screw as shown in the figure.
-Remove the rubber seal and the speedo gear.
-Fit the new gear by following the steps in reverse
order.
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
SUSP - 122
ET4 50
ET4 50
Suspensions
Handlebar
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 operations in the reverse order to the
removal, observing the prescribed tightening torque.
Locking torques (N*m)
Handlebar lock nut 45 ÷ 50
Front fork
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 - 123
Suspensions
ET4 50
- 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
- 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
Overhaul
CAUTION
USE NEW ROLLER CASINGS, PIN, SEALING RINGS AND DUST GUARDS FOR REFITTING.
Refitting
- Lubricate the sealing rings with mineral oil and
half-fill the roller casings with grease.
- Insert the seal 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.
SUSP - 124
ET4 50
Suspensions
- Push, from the handgrip, the wedging washer roller casing - seal ring unit, placing part 16 until it
stops on the swinging hub
- Repeat the operation described above using the
tool fitted with part 16 and part 22* instead of part
4 on the stem, on the side opposite the one shown
in the figure to refit the second wedging washer roller casing - sealing ring unit.
* 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
- 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
SUSP - 125
Suspensions
- 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.
Specific tooling
020055Y Wrench for steering tube ring nut
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 - 126
ET4 50
ET4 50
Suspensions
Steering column
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
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.
Shock-absorber - calliper bracket
Removal
- Using a suitable drift, drive out the two needle
bearings from the side opposite to the assembly
side.
SUSP - 127
Suspensions
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
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
- Lubricate the races and balls with grease.
- Tighten to the specified torque and then turn the
tool 120° anti-clockwise.
Specific tooling
020055Y Wrench for steering tube ring nut
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
Locking torques (N*m)
Tightening torque: 8 ÷ 10 Nm
SUSP - 128
ET4 50
ET4 50
Suspensions
Refitting
Specific tooling
020055Y Wrench for steering tube ring nut
Locking torques (N*m)
Tightening torque 30 ÷ 40
Rear
Removing the rear wheel
-Straighten the split pin and remove the cap.
-Remove the wheel acting on the central fixing
point.
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
SUSP - 129
INDEX OF TOPICS
BRAKING SYSTEM
BRAK SYS
ET4 50
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
- Slacken the two fixings between the support and
the shock absorber.
- Remove the circlip from the wheel spindle.
- Remove the speedometer cable.
- Withdraw the calliper support.
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.
BRAK SYS - 131
Braking system
ET4 50
- 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);
- 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 at 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
BRAK SYS - 132
ET4 50
Braking system
Refitting
-Perform the disassembly steps in reverse order.
-Fit a new O-ring.
-Torque the two screws to the prescribed value.
- Fit the spacer and O-ring on the wheel spindle.
Locking torques (N*m)
Tightening torque 20 ÷ 25
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)
tightening torque 5 ÷ 6.5 Nm
Disc Inspection
Specific tooling
020335Y Magnetic support for dial gauge
Characteristic
Max oscillation allowed
0.1 mm.
BRAK SYS - 133
Braking system
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 brake pump
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.
BRAK SYS - 134
ET4 50
ET4 50
Braking system
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.
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 Brake-shoe spring calliper
BRAK SYS - 135
INDEX OF TOPICS
CHASSIS
CHAS
ET4 50
Chassis
- Remove the screw and disconnect the electric
terminals.
Rear rack
- Tip up the saddle.
- Remove the helmet compartment.
- Remove the plastic fairing under the saddle after
unscrewing the three screws shown in the figure.
- Remove the plastic cover on the luggage-carrier.
- Unscrew the three screws and remove the luggage-carrier.
CHAS - 137
Chassis
Rear handlebar cover
Undo the screws as shown in the figure and remove the handlebar rear section.
Instrument panel
Loosen the two screws and disconnect the terminal block.
- Remove the rubber hood and then the retaining
clip as shown in the figure.
Operate the 4 screws shown in the figure to replace the instrument panel.
CHAS - 138
ET4 50
ET4 50
Chassis
Front handlebar cover
-Remove the handlebar front fairing as shown in
the figure.
- To remove the handlebars, use 2 spanners
(17-13 mm) as shown in the figure after detaching
the LH and RH controls.
Locking torques (N*m)
Handlebar lock nut 45 ÷ 50
Headlight assy.
To replace the headlight, unscrew the 2 screws.
-Remove the bulbs as shown in the figure.
CHAS - 139
Chassis
The bulbs have a bayonet fitting. Simply rotate
them1/4 of a turn to extract and replace them.
Legshield
- To replace the grille, first remove the Piaggio
emblem and then the screw located underneath
Footrest
- Operate on the 3 screws shown in the figure once
the glove-box and fairing have been removed.
CHAS - 140
ET4 50
ET4 50
Chassis
Side fairings
-Remove the screws under the footboard mat,
then remove the two side fairings, by disengaging
the interlocking elements.
License plate holder
- Unscrew the 2 side screws and the 2 nuts at the
back of the splash guard.
- Unclip the number plate light.
Rear central cover
- Unscrew the screw as shown in the figure, then
remove the spark plug access door.
CHAS - 141
Chassis
Front mudguard
- Unscrew the screw as shown in the figure and
remove the plastic fairing.
Top-case
Front
- Press the spring clip with a screwdriver and withdraw the switch lock. To remove the part of the lock
that is left inside the steering tube, you must first
disassemble the steering tube.
- Loosen the 2 screws and detach the door.
CHAS - 142
ET4 50
ET4 50
Chassis
- Unscrew the 2 screws shown in the figure placed
under the front grille.
- Remove the 3 screws shown in the figure, placed
inside the glove-box; they can be reached after
opening the glove-box door.
CHAS - 143
INDEX OF TOPICS
PRE-DELIVERY
PRE DE
ET4 50
Pre-delivery
Aesthetic inspection
- Paintwork
- Joins between plastic fairings
- Damage
- Cleanness
Tightening torques inspection
Fastenings check
- All tightening torques
- External fairing screws
SAFETY LOCKS
Name
Handlebar tightening
Lower steering ring nut
Upper steering ring nut
Front wheel axle nut
Rear wheel nut
Rear shock absorber-engine nut
Shock absorber - chassis nut
Engine-swinging arm bolt
Floating arm-frame pin
Torque in Nm
40 ÷ 50
8 ÷ 10
30 ÷ 40
75 ÷ 90
137 ÷ 152
33 ÷ 41
20 ÷ 25
33 ÷ 41
44 ÷ 52
Electrical system
- Check that voltage is at least 12.6V; if not, recharge the battery according to directions.
Check the following devices:
- Keyswitch
- Headlight full/dipped beam, panel indicator lights, side lights
- Headlight adjustment
- Taillight
- Brake light (front and rear brake)
- Turn signals and relative indicators
- Speedometer and instrument panel lighting
- Horn
- Start button
CAUTION
TO ENSURE BEST PERFORMANCE, BATTERY MUST BE CHARGED BEFORE USE ONLY IF
VOLTAGE IS BELOW 12,7V. FAILURE TO RECHARGE THE BATTERY BEFORE ITS FIRST USE
MAY SHORTEN THE BATTERY'S LIFE.
WHEN INSTALLING THE BATTERY ON THE VEHICLE CONNECT THE POSITIVE LEAD BEFORE
THE NEGATIVE LEAD.
NEVER USE A FUSE WITH A HIGHER RATING THAN THE PRESCRIBED VALUE. THE USE OF
UNSUITABLY RATED FUSES CAN RESULT IN WIDESPREAD DAMAGE TO THE VEHICLE, INCLUDING FIRE.
PRE DE - 145
Pre-delivery
ET4 50
WARNING
KEEP THE BATTERY WELL CLEAR OF NAKED FLAMES AND SPARKS DURING CHARGING.
REMOVE THE BATTERY FROM THE VEHICLE BY DISCONNECTING THE NEGATIVE LEAD
FIRST.
PROTECT THE EYES WHEN WORKING WITH BATTERIES OR IN THEIR IMMEDIATE VICINITY.
KEEP BATTERIES AWAY FROM CHILDREN. BATTERY ELECTROLYTE CONTAINS SULPHURIC
ACID. BATTERY ELECTROLYTE IS POISONOUS AND CAUSES SEVERE BURNS. AVOID CONTACT WITH THE EYES, SKIN AND CLOTHES. DO NOT FORCE OR DAMAGE THE EXTERNAL
CASE.
IN CASE OF CONTACT WITH THE EYES AND/OR SKIN, WASH THE AFFECTED AREA WITH
PLENTY OF CLEAN WATER FOR ABOUT 15 MINUTES AND SEEK MEDICAL ASSISTANCE IMMEDIATELY.
IN THE CASE OF INGESTION OF ELECTROLYTE DRINK PLENTY OF WATER OR VEGETABLE
OIL AND CALL A DOCTOR IMMEDIATELY.
Levels check
- Brake fluid
- Hub oil
- Engine oil level
Road test
− Cold start.
− Speedometer check.
− Throttle check.
− Riding stability.
− Front and rear brake efficiency.
− Front and rear shock-absorbers.
− Unusual noises.
− Hot engine restart.
− Leakages (after trial run).
Functional inspection
− Brake lever excursion.
− Throttle excursion and adjustment.
− Homogeneous steering turning.
Other
- Tyre inflation pressure
- Locks
- Mirrors and accessories
- Toolkit, user handbook, guarantee certificate and customer service card
CAUTION
CHECK AND ADJUST TYRE PRESSURE WITH TYRES AT AMBIENT TEMPERATURE.
PRE DE - 146
ET4 50
Pre-delivery
CAUTION
NEVER EXCEED THE RECOMMENDED INFLATION PRESSURES OR TYRES MAY BURST.
WARNING
BE VERY CAREFUL WHEN HANDLING FUEL.
PRE DE - 147
INDEX OF TOPICS
TIME
TIME
ET4 50
Time
Engine
ENGINE
1
Code
001001
2
3
4
001127
003064
003057
Action
Engine from frame - Removal and refit.
Engine - Complete service
Engine oil - Change
Engine retainer - Tighten nuts
Duration
TIME - 149
ET4 50
Time
Crankcase
CRANKCASE
1
Crankshaft
TIME - 150
Code
001133
Action
Engine crankcase - replace
Duration
ET4 50
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 ASSY.
1
Code
001002
Action
Cylinder piston - Replacement
Duration
Cylinder head assy.
TIME - 151
ET4 50
Time
HEAD
1
2
3
4
5
Code
001056
001045
001079
001126
001049
Action
Head gasket - change
Valves - Replacement
Head parts - Disassembly / assembly
Head - Replacement
Valves - Adjustments
Duration
Rocker arms support assy.
CAMSHAFT SUPPORT
1
2
3
TIME - 152
Code
003056
001148
001044
Action
Head/Cylinder - Nut tightening
Rocking lever valve - Replacement
Camshaft - Replacement
Duration
ET4 50
Time
Cylinder head cover
HEAD COVER
1
2
3
4
Code
001093
001088
001097
001089
Action
Spark plug - Replacement
Head cover gasket - change
Cooling hood - Replacement
Head cover - change
Duration
TIME - 153
ET4 50
Time
Driven pulley
DRIVEN PULLEY - CLUTCH
1
2
3
4
5
6
Code
001110
001012
003065
001022
003072
001156
7
001155
TIME - 154
Action
Driven pulley- Replacement
Driven pulley - Overhaul
Gear casing oil - Replacement
Clutch - Replacement
Clutch assembly - Wear check
Reduction gearing cover - Replacement
Clutch bell housing - Replacement
Duration
ET4 50
Time
Oil pump
OIL PUMP
1
2
3
4
5
6
7
8
Code
001051
001112
001042
001121
001122
001125
001130
001129
Action
Belt/Timing chain - change
Oil pump - change
Oil pump - overhaul
Chain cover oil seal - Replacement
Oil pump chain - change
Chain guide pads - change
Oil sump - change
Chain tightener - overhaul and replace
Duration
TIME - 155
ET4 50
Time
Final gear assy.
REDUCTION GEAR
1
2
TIME - 156
Code
001010
004125
Action
Gear reduction unit - Inspection
Rear wheel axle - Replacement
Duration
ET4 50
Time
Driving pulley
DRIVING PULLEY
1
2
3
4
Code
001006
001086
001066
001011
Action
Driving pulley - Overhaul
Driving half-pulley - replace
Driving pulley - Removal and refitting
rear-view belt - Replacement
Duration
TIME - 157
ET4 50
Time
Transmission cover
TRANSMISSION COVER
1
Code
001096
2
001132
3
001131
4
001135
TIME - 158
Action
Transmission crankcase cover - replace
Transmission air intake pipe - Replacement
Transmission air intake - Replacement
Transmission cover bearing - Replacement
Duration
ET4 50
Time
Starter motor
STARTER MOTOR - START UP LEVER
1
2
3
Code
001020
001017
005045
4
5
6
001084
008008
001021
Action
Starter motor - change
Starter sprocket wheel - replace
Starter motor with cables unit - Replac.
Starter lever - Replacement
Starter spring pack - Replacement
Kick starter - Inspection
Duration
TIME - 159
ET4 50
Time
Flywheel magneto
FLYWHEEL FAN
1
2
3
4
5
TIME - 160
Code
001067
001058
001102
001109
001087
Action
Stator - Fitting and Refitting
Flywheel - Replacement
Net oil filter - change / Cleaning
Cooling fan - Replacement
Flywheel cover - Replacement
Duration
ET4 50
Time
Carburettor
FUEL TANK
1
2
3
4
5
Code
004005
004110
005010
004007
004109
Action
Fuel tank - Replacement
Fuel tank hose - Replacement
Tank float - Replacement
Fuel valve - Replacement
Fuel tank breather - Replacement
Duration
TIME - 161
ET4 50
Time
Exhaust pipe
MUFFLER
1
2
TIME - 162
Code
001009
001095
Action
Muffler - Replacement
Muffler guard - Replacement
Duration
ET4 50
Time
Air cleaner
AIR FILTER
1
2
Code
001014
001015
Action
Air filter - Replacement /Cleaning
Air filter box - Replacement
Duration
TIME - 163
ET4 50
Time
Frame
FRAME
1
2
3
4
Code
004001
004023
004012
004059
5
6
006001
006032
TIME - 164
Action
Frame - replace
Shield rim - Replacement
Rear fairings - Removal and refitting
Spark plug inspection flap - Replacement
Frame - Painting
Door - Painting
Duration
ET4 50
Time
Centre-stand
STAND
1
2
3
Code
004004
001053
001072
Action
Stand - Replacement
Stand bolt - Replacement
Swinging arm - Engine-chassis connection - Replacement
Duration
TIME - 165
ET4 50
Time
Rear cover
GLOVE COMPARTMENT
1
2
Plate holder
TIME - 166
Code
004081
004083
Action
Glove box door - Replacement
Glove box - Replacement
Duration
ET4 50
Time
NUMBER PLATE HOLDER
1
Code
005032
2
005031
3
005048
Action
Licence plate light glass - Replacement
Licence plate light bulb - Replacement
Licence plate holder - Replacement
Duration
Mudguard
MUDGUARDS
1
2
Code
004002
004009
Action
Front mudguard - Replacement
Rear mudguard - Replacement
Duration
TIME - 167
ET4 50
Time
Rear shock-absorber
FRONT SHOCK ABSORBER COVER
1
Code
003011
2
003044
3
006038
TIME - 168
Action
Front shock absorber - Removal and
Refitting
Shock absorber cover - Replacement
Shock absorber cover - Painting
Duration
ET4 50
Time
REAR SHOCK ABSORBER
1
Code
003007
Action
Rear shock absorber - Removal and
Refitting
Duration
Steering column bearings
TIME - 169
ET4 50
Time
STEERING COLUMN BEARINGS
1
2
Code
003002
003073
Action
Steering fifth wheel - Replacement
Steering clearance - Adjustment
Duration
Handlebar covers
ODOMETER - HANDLEBAR COVERS
1
Code
004018
2
004019
3
4
5
005014
006013
005038
6
006014
TIME - 170
Action
Handlebar front section - Replacement
Handlebar rear section - Replacement
Odometer - Replacement
Handlebar front part - Painting
Instrument panel warning light bulbs
- Replacement
Handlebar rear part - Painting
Duration
ET4 50
Time
Handlebar components
HANDLEBAR COMPONENTS
1
2
3
4
5
Code
002037
002071
003001
004066
003075
Action
Brake or clutch lever - Replacement
Left hand grip - Replacement
Handlebar - Removal and refitting
Driving mirror - Replacement
Handlebar left control - Replacement
Duration
TIME - 171
ET4 50
Time
HANDLEBAR COMPONENTS
1
2
3
4
Code
002037
002059
003067
003074
5
002047
6
002024
7
002063
8
005017
Action
Brake or clutch lever - Replacement
Right hand grip - Replacement
Front brake fluid - Renewal
Handlebar right control - Replacement
Front brake fluid and air bleeding
system - Replacement
Front brake pump - Removal and Refitting
Throttle control transmission - Replacement
Stop switch - Replacement
Duration
Seat
SADDLE
1
2
3
TIME - 172
Code
004008
004003
004054
Action
Luggage rack - Replacement
Saddle - Replacement
Seat lock hook - Replacement
Duration
ET4 50
Time
Turn signal lights
REAR RED LAMP
1
2
Code
005066
005028
3
005068
4
5
005005
005022
Action
Rear light bulbs - Replacement
Rear light assembly glass - Replacement
Rear turn indicator bulb - Replacement
Taillight - Replacement
Rear turn indicators - Replacement
Duration
Front wheel
FRONT WHEEL
1
Code
003047
2
003037
3
004123
4
003063
5
006018
Action
Front tyre - replace
Front wheel rim Removal and
Refitting
Front wheel - Replacement
Tyre pressure Check
Wheel rim Paintwork
Duration
TIME - 173
ET4 50
Time
Grease tone wheel or
drive
Please take note that
the code has been introduced:
900001 - Tone wheel /
drive greasing - 15'.
Never mistake the codes 002011 (movement
sensor replacement)
and 005089 (tone
wheel replacement) in
the event of noise of the
indicated components.
The grease recommended is TUTELA MRM 2
(soap-based lithium
grease with Molybdenum disulphide).
In the following points
we indicate with an arrow the area to be
greased (1 - Drive, 2 Tone wheel)
Rear wheel
REAR WHEEL
1
2
3
TIME - 174
Code
001016
004126
001071
Action
Rear wheel - Replacement
Rear wheel tyre - Replacement
Rear wheel rim - Replacement
Duration
ET4 50
4
5
Time
Code
003063
006018
Action
Tyre pressure - Check
Wheel rim - Paintwork
Duration
Electric devices
HEADLIGHT
1
2
3
4
Code
005008
005002
005012
005067
5
6
005044
004020
Action
Front headlamp bulbs - Replacement
Front headlamp - Replacement
Front turn indicator - Replacement
Front turn indicator bulb - Replacement
Front lights cable unit- Replacement
Headlight frame - Replacement
Duration
TIME - 175
ET4 50
Time
ELECTRICAL DEVICES
1
2
3
4
Code
001069
001094
005009
005001
5
005035
6
7
001023
005074
TIME - 176
Action
HV coil - Replacement
Spark plug cap - Replacement
Voltage regulator - Replacement
Electrical system - Removal and refitting
Headlight remote control - Replacement
Control unit - Replacement
Choke control device - Replacement
Duration
ET4 50
Time
ELECTRIC DEVICES
1
2
Code
005003
005006
3
4
5
6
7
8
9
005039
005040
005041
004010
004096
005069
005016
Action
Horn - Replacement
Light switch or turn indicators - Replacement
Headlight switch - Replacement
Horn button - Replacement
Starter button - Replacement
Antitheft lock - replace
Lock series - Replacement
Left switch - Replacement
Key switch - Replacement
Duration
TIME - 177
ET4 50
Time
ELECTRIC DEVICES
1
2
Code
005007
005011
3
4
5
005019
005024
005025
TIME - 178
Action
Battery - Replacement
Start-up remote control switch - Replacement
Fuse terminal block - Replacement
Battery fuse - Replacement
Battery fuse holder - Replacement
Duration
ET4 50
Time
Transmissions
TRANSMISSIONS
1
Code
002051
2
3
002049
002053
4
5
6
002043
003060
002021
Action
Odometer transmission assembly Replacement
Odometer cable - Replacement
Rear brake transmission complete Replacement
Rear brake cable - Replacement
Rear brake cable - Adjustment
Front brake piping - Replacement
Duration
TIME - 179
ET4 50
Time
Brake callipers
BRAKE CALIPER
1
Code
003035
2
002039
3
002011
4
003036
5
003070
6
002007
7
8
003002
003073
TIME - 180
Action
Shock absorber support and brake
calliper - Replacement
Front brake calliper - Removal and
Refitting
Odometer movement sensor - Replacement
Shock abs. and brake caliper support
bearings - Replacement
Front brake pads / Shoes - Check
wear
Front brake shoes/pads - Remov.
and Refitt
Steering fifth wheel - Replacement
Steering clearance - Adjustment
Duration
ET4 50
Time
Footrests
MATS
1
2
Code
004015
004078
3
004075
Action
Footrest - Removal and Refitting
Front/rear footboard rubber cover Replacement
Front mat - Replacement
Duration
TIME - 181
ET4 50
Time
Steering column
STEERING
1
2
3
4
5
6
TIME - 182
Code
003045
003010
002041
003040
001064
003033
Action
Steering tube - Replacement
Front suspension - Service
Brake disc - Replacement
Front wheel bearings - Replacement
Odometer reel - Replacement
Front wheel hub- Replacement
Duration
ET4 50
Time
Helmet bay
HELMET CARRIER
1
Code
004016
2
3
4
004071
005046
001027
Action
Helmet compartment - Removal and
Refitting
Battery compartment - Replacement
Battery cover - Replacement
Body / air cleaner union - Replacement
Duration
Braking system
TIME - 183
ET4 50
Time
BRAKE LEVER
1
TIME - 184
Code
002002
Action
Shoes - Rear brake pads - Replacement
Duration
A
Air filter: 30
B
Battery: 38, 44, 53
Brake: 131, 133–135, 180
C
Carburettor: 10, 28, 108, 112, 161
E
Engine oil: 31
F
Fuel: 36, 107
H
Headlight: 139
Hub oil: 30
I
Identification: 8
Instrument panel: 138
M
Maintenance: 7, 25
O
Odometer:
S
Saddle:
Spark plug: 29
Stand:
T
Tank:
Transmission: 9, 37, 59, 69, 158
Tyres: 10