Malaguti 500 cc 4T User manual

110/07
MALAGUTI S.p.A.
Via Emilia 498, 40068 - San Lazzaro di Savena (BO) - ITALY
Tel.[phone]-Fax[phone]
e-mail:inf[email protected]- http:// www.malaguti.com
FOREWORD
• The present manual specifically addresses to specialised technical personnel (MALAGUTI authorised service centres and single motor mechanics) and contains all the
service interventions indicated by the Manufacturer until the publishing of this document.
•Some basic technical information has been intentionally omitted as it is considered to be common knowledge.
• Additional information isavailable in the SPARE PARTS CATALOGUE andin the SERVICE MANUAL - FRAME AND RUNNING GEAR section.
• It is important toreadallthegeneralinformationbeforegoing through the manual to the specifictopicsandthemaintenanceoperationsto be carried out on the engine inorder
to make sure the topics, the technical and safety concepts are clearly understood and the manual can be used as a sure reference text.
•All checks, maintenance,repairs or replacements of spare parts etc... are to be performed by skilled and expert technical personnel with specific experience in state-of-
the-art technology and full knowledge of the quickest and most rational procedures, technical characteristics, setting values, tightening torques and information as to which
may only be properly and exhaustively provided by the manufacturer.
• It is important toadhere strictly to thefollowinginstructions.Any operationcarriedout carelessly or notcarried outatall may,damagethe engine or simplylead tocomplaints.
MALAGUTI S.p.A. reserves the right to make any changes and modifications hereto it deems necessary without prior notice.
For further information and details, please contact MALAGUTI S.p.A.Servicing Division.

210/07
GENERAL WORK PROCEDURES
• The recommendations given hereafter are aimed at ensuring maximum work safety as well as at considerably reducing the risk of accidents, personal injury, equipment
damage and idle times, and should therefore be strictly adhered to.
• Always listen withattention to thecustomer’s opinion andcomplaints about the engineoperation, asking specificquestions in orderto have a completeunderstanding of all the
symptoms and identify with good approximation the real causes of the trouble. The present manual provides the technical information and the basic indications on the
intervention procedures but these have to be integrated with the personal expertise.
• We suggest planning the service interventions in order to avoid any waste of time or downtime.Try to reduce as much as possible the operations necessary to reach the
componentsthatneeds repairing.
• Prepare the components that are likely to be replaced and all the original spare parts you may need.
• Mark the components thatmay be mis-placed during re-assemblyoperations.
• Only use quality tools and equipment.
• During operations, always keep tools and equipment at hand, possibly laying them out according to the sequence in which they are to be used.
• Always keep the work area neat and clean.
• When tightening screws or nuts, start with the larger diameter or inner fasteners, and tighten them in progressive “pulls”using a “criss-cross”pattern.
• The torque settings specified in the manual refer to the “final torque”, which must be attained progressively by steps.
• Preferably use open-endbox wrenches by“pulling”and not “pushing”.
• For operations requiring two mechanics, make sure that the various stepsto be performed by each of them are clearly defined and co-ordinated beforehand.
• Make sure that eachcomponent has been properly mounted beforeproceeding with assembling the next one.
•Always replace gaskets, O-rings, circlips and split pins at every refitting.
• Only use screwdrivers with sizes suitable to the screws to be loosened or tightened.
Never use open flames for any reason.
Always use low flash point solvents to clean the vehicle components.
When welding, make sure that there are no flammable liquids in the vicinity.
• Never reuse old gaskets or circlips.
• Never use a screwdriver as a lever or chisel.
• Never use pincers to loosen or tighten screws or nuts.
•Never tap the wrench with a hammer or other similar tool to loosen or tighten screws and nuts.
•Never attempt to increase the lever arm by fitting a tube into the wrench.

310/07
DESCRIPTION P.
SPECIFICATIONS 4
TIGHTENING TORQUES 5
AUTOMATIC TRANSMISSION 10
Transmissioncover 10
Air duct - Air duct filter 11
Removing the driven pulley shaft bearing 11
Refitting the driven pulley shaft bearing 12
BAFFLE ROLLER 12
Plastic roller 12
Removing the driven pulley - Inspecting the clutch drum 13
Removing the clutch 13
Inspecting the clutch - Pin retaining collar 14
Removingthedrivenhalf-pulleybearing 14
Inspecting the driven fixed half-pulley 15
Inspecting the driven sliding half-pulley 15
Refitting the driven half-pulley bearing 15
Refitting the driven pulley - Inspecting the clutch spring 16
Refitting the clutch 16
Refitting the driven pulley - Drive-belt 17
Removingthe driving pulley 17
Inspecting the rollers case - Refitting the driving pulley 18
Refitting the transmission cover 20
ENDGEAR 21
Removing the hub cover - Removing the wheel axle 21
Removing the hub bearings 21
Removing the wheel axle bearings 22
Removing the driven pulley shaft bearing 23
Inspecting the hub shaft 23
Inspecting the hub cover 23
Refitting the driven pulley shaft bearing 24
Refitting the hub cover bearings 25
Refitting the hub bearings - Refitting the ub cover 26
FLYWHEELCOVER 26
Removingthehub cover 27
Removing the flywheel cover components 27
Removing the stator - Inspecting the cover components 28
Refitting the stator 29
Refitting the flywheel cover components 30
Refitting the flywheel cover 31
DESCRIPTION P.
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FLYWHEELAND STARTING 33
Removing the starter motor - Removing the flywheel magneto 34
Inspecting the flywheel components - Starter gear rim 36
Intermediate gear - Refitting the free wheel 37
Refitting the intermediate gear - Refitting the flywheel magneto 38
Refitting the starter motor 39
CYLINDER ASSY. AND TIMING SYSTEM 40
Removing the intake manifold - Removing the rocker-arms cover 40
Removing the timing system drive 40
Removing the cam shaft 41
Removing the cylinder head 42
Removingthe valves 43
Removing the cylinder-piston assy - Inspecting the small end - Inspecting the wrist pin44
Inspecting the piston 45
Inspecting the piston rings 46
Removing the piston 47
Choosing the gasket 48
Refitting the piston rings - Refitting the cylinder - Inspecting the cylinder head 49
Inspecting the timing system components - Inspecting the valve sealings 50
Inspecting the valve housings 50
Inspecting the valves - Inspecting the valve stem guide clearance 51
Inspecting the springs and half-cones 52
Refitting the valves - Inspecting the cam shaft 53
Refitting the head and timing system components 54
Refitting the timing chain 58
Refitting the rocker-arms cover 59
Refitting the intake manifold 60
CRANKCASE - CRANKSHAFT 60
Splitting the crankcase halves - Removing the crankshaft 61
Removing the countershaft - Replacing the countershaft bearings 62
Inspecting the crankshaft components - Inspecting the crankshaft alignment 64
Inspecting the crankcase halves 65
Inspecting the crankshaft plain bearings 66
Countershaft - Refitting the crankshaft 68
Refitting the crankcase halves 69
LUBRICATION 70
Conceptual diagrams - General characteristics 71
Diagnosis guide 72
Oil pressure check - Oil pump 74
CONTENTS

410/07
Specification Desc./Quantity
Ignition High efficiency electronic inductive ignition,
integrated with the injection system, with
variable advance and separate HV coil.
Spark plug (2) NGK CR7EKB
Specification Desc./Quantity
Engine oil (at oil and filter change) 1.7 l
Transmission oil 250 cm³
Specification Desc./Quantity
Transmission Automatic expandable pulley variator with
torque server, V belt, automatic clutch.
Specification Desc./Quantity
Type Single-cylinder, 4-stroke with double spark
plug
Bore x Stroke 94 x 71 mm
Cubic capacity 493 cm³
Compression ratio 10.5: 1
Timing system Four valves, single overhead camshaft, chain
driven.
Valve clearance Inlet: 0.15 mm
Outlet: 0.15 mm
Engine idle speed 1,500 ± 100 rpm
Start-up Electric
Lubrication Engine lubrication with trochoidal pump
(inside the crankcase), oil filter and pressure
adjustment by-pass.
Fuel supply Electronic injection with electric fuel pump.
MAX. power 29 kW at 7,500 rpm
MAX torque 44 Nm at 5,200 rpm
Cooling Forced coolant circulation system.
ENGINE
CAPACITY
TRANSMISSION
ELECTRICAL SYSTEM
Specifications

510/07
Name Torque in Nm
Countershaft fixing nut 25 ÷ 29
Engine oil filter 12 ÷ 16
Engine oil drainage plug 24 ÷ 30
Engine-crankcase coupling screws 11 ÷ 13
Oil pump screws 5 ÷ 6
Gear mounting on crankshaft screws 10 ÷ 12
Bulkhead screws for oil pump housing cover 8 ÷ 10
Name Torque in Nm
Rear hub cover screws 24 ÷ 27
Name Torque in Nm
Driven pulley nut 92 ÷ 100
Drive pulley nut 160 ÷ 175
Anti-vibration roller screw 16.7 ÷ 19.6
M8 retainers for transmission cover 23 ÷ 26
M6 retainer 11 ÷ 13
Anti-vibration roller retainer 17 ÷ 19
Clutch ring nut 65 ÷ 75
Air deflector unit screws 7 ÷ 9
Water pump cover screws 3 ÷ 4
Outside transmission cover screws 7 ÷ 9
Flywheel cover screws 11 ÷ 13
Name Torque in Nm
Starter motor retainers 11 ÷ 13
ENGINE ASSEMBLY
Tightening Torques
THERMAL UNIT AND TIMING SYSTEM
TRANSMISSION COVER
CRANKCASEAND CRANKSHAFT
FINAL REDUCTION
*** Apply a preliminary torque of 7 Nm in a crossed sequence.
- Tighten by 90° in a crossed sequence.
- Tighten again by 90° in a crossed sequence.
Name Torque in Nm
Spark plug 12 ÷ 14
Head fixing stud bolts: ***
Head fixing nuts 10 ÷ 12
Exhaust/intake head fixing nuts: 10 ÷ 12
Head lubrication control jet 5 ÷ 7
Coolant temperature sensor 10 ÷ 12
counterweight mass fixing screw 7 ÷ 8.5
Tensioner sliding block fixing screw: 10 ÷ 14
Rpm timing sensor fixing screw: 3 ÷ 4
Injector fixing screw 3 ÷ 4
Rpm timing sensor fixing screw 3 ÷ 4
Valve lifter mass stop bell fixing screws: 30 ÷ 35
inlet manifold fixing screws 11 ÷ 13
Tappet cover fixing screws: 7 ÷ 9
Throttle body fixing screws 11 ÷ 13
Camshaft retaining bracket fixing screws 4 ÷ 6
Head fixing screws 10 ÷ 12
Lambda probe on exhaust manifold 10 ÷ 12
Muffler to bracket fixing screw 14 ÷ 16

610/07
Name Initials Cylinder Piston Play on fitting
Cylinder- Piston A 93.990÷93.997 93.954÷93.961 0.029÷0.043
Cylinder- Piston B 93.997÷93.004 93.961÷93.968 0.029÷0.043
Cylinder- Piston C 94.004÷94.011 93.968÷93.975 0.029÷0.043
Cylinder- Piston D 94.011÷94.018 93.975÷93.982 0.029÷0.043
Specification Desc./Quantity
Cylinder diameter C 94
Piston diameter P 93.968
Specification Desc./Quantity
A 10 mm
B 43 mm
Name Torque in Nm
Oil pump cover screws 0.7 ÷ 0.9
Screws fixing oil pump to the crankcase 5 ÷ 6
Name Torque in Nm
Flywheel fixing nut 115 ÷ 125
Stator retainers 8 ÷ 10
Blow-by recovery duct fixing screws 3 ÷ 4
Screw fixing freewheel to flywheel 13 ÷ 15
Stator cable harness guide bracket screws 3 ÷ 4
FLYWHEEL COVER
LUBRICATION
Overhaul data
Thissectionprovides the main informationforscooter servicing.
Assembly clearances cylinder - piston assy
HEIGHT TO MEASURE PISTON AND CYLINDER
CYLINDER - PISTON
N.B.
THEPISTONMUSTBEINSTALLEDWITHTHEARROWFACINGTOWARDSTHEOUTLET
SIDE, THE PISTON RINGS MUST BE INSTALLED WITH THE WORD "TOP" OR THE
STAMPEDMARKFACINGUPWARDS.
COUPLING CATEGORIES
+0,018
-0,01
±0,014

710/07
Specification Desc./Quantity
A 0.15 mm
B 0.010 mm
C 0.010 mm
D 0.10 mm
Specification Desc./Quantity
Cat. 1 Standard diameter: 40.010 ÷ 40.016
Cat. 2 Standard diameter: 40.016 ÷ 40.022
Piston rings
*Fit rings "2" and "3" with the word "TOP" facing upwards.
** Position the openings in the rings as shown here.
***Value "A" of sealing ring inside the cylinder.
Check the size of the sealing ring opening:
Compression ring: 0.15 ÷ 0.35 mm. Max. value 0.5 mm
Oil scraper ring: 0.25 ÷ 0.50 mm. Max. value 0.65 mm
Oil scraper ring: 0.25 ÷ 0.50 mm. Max. value 0.65 mm
Rings/housing coupling clearances:
Carefullyclean the sealing ringhousings.
Place a thickness gauge between the ring and the hou-
singasshownin the drawing andcheckthe coupling cle-
arances.
Top ring
Standard coupling clearance: 0.01÷0.06 mm
Maximum clearances allowed after use: 0.10 mm
Intermediate ring
Standard coupling clearance: 0.02÷0.07 mm
Maximum clearances allowed after use: 0.10 mm
Oil scraper ring
Standard coupling clearance: 0.01÷0.06 mm
Maximum clearances allowed after use: 0.10 mm
Replace the piston if clearances exceed the maximum
limits specified in the table.
MAX. ADMISSIBLE DISPLACEMENT
Crankcase - crankshaft - connecting rod
Diameter of crankshaft bearings.
Measure the capacity on both axes x-y.
CRANKSHAFT
Crankshaft alignment
Specific tooling
020335Y
Magneticsupport for dialgauge

810/07
Crankshaft-crankcase axial clearance (H)
0.1÷ 0.405 mm (when cold)
Compression ratio
10.5: 1
AXIAL CLEARANCE BETWEEN CRANKSHAFT AND CONNECTING ROD
Thevalue of the“M” fixture axialclearance is acceptablewithin the rangeof
0.20 ÷ 0.60 mm
Description Dimensions
Transmission-sideshoulder E = 1 ± 0,025
Half-shaft, transmission side F = 20,9
Connectingrod G = 22
Flywheelside half-shaft H = 19,6
Flywheel-sideshoulder I = 1,8 ± 0,025
Completecrankshaft L = 65,5
0
-0.05
-0.10
-0.15
0
-0.05
+0.10
-0.05

910/07
Name Measure A Thickness
«A» MEASURE TAKEN - 0.185 - - 0.10 0.4 ± 0.05
«A» MEASURE TAKEN - 0.10 - + 0.10 0.6 ± 0.05
«A» MEASURE TAKEN + 0.10 - + 0.185 0.8 ± 0.05
Slot packing system
Shimming system to control compression ratio
DISTANCE"A" ISAPROTRUSIONORRECESS VALUEOFTHEPISTON
CROWNWITHRESPECTTOTHECYLINDERPLANE.
DISTANCE"A"HELPS DETERMINETHETHICKNESS OF GASKET"B"THAT
HAS TO BE FITTED TO THE CYLINDER HEAD IN ORDER TO RESTORE
COMPRESSIONRATIO. BASE GASKET"B" MUSTBETHICKERTHE MORE
THEPLANEFORMEDBYTHEPISTONTOPPROTRUDESFROMTHEPLANE
FORMEDBY THECYLINDERHEAD.ONTHEOTHERHAND,THEMORE THE
PISTONTOPISRECESSEDINTOTHECYLINDERTOPPLANE,THESMALLER
THEGASKETTHICKNESS.
N.B.
VALUES INDICATED WITH "-" REFER TO PISTON CROWN RECESSES WITH
RESPECTTOTHE CYLINDER PLANE.
N.B.
DISTANCE "A" MUST BE MEASUREDWITHOUT ANY GASKET FITTED AT "B"
RECOMMENDED LUBRICATING TABLE
BASE GASKET THICKNESS
Product Description Specifications
Q8 ZC90 SAE 80W-90 Rear hub oil SAE 80W/90 Oil
Q8 FORMULA EXCEL SAE
5W - 40 Engine oil SAE 5W-40 Synthetic oil
- Grease for the tone wheel
revolving ring Soap-based lithium grease containing
Molybdenum disulphide

10 10/07
- Remove the six M6 screws.
-Removethe four M8screws.
-Removethetransmissioncover.
- Check that the bearing rotates freely,
otherwisereplace it.
Automatic
transmission
Transmission cover
- Loosen the 4 fastening screws
- Extract the outside plastic
transmissioncover.
-Usingascrewdriver,removethedriven
pulleyaxle cover near the bottomof the
cap.
-Loosenthe drivenpulleyshaftfastening
nutusingamisalignedwrenchand
preventthepulleyshaft rotation using a
machinehexagon bush.
-Removethenut and the two washers.
N.B.
DUETO THE HIGH TIGHTENING TORQUE,
USINGDIFFERENTWRENCHES- SUCHAS
A CONVENTIONAL POLYGONAL BUSH -
MAYDAMAGETHEHEXAGONOBTAINEDON
THESHAFTORBREAKTHEBUSHITSELF.

11 10/07
Air duct
-Removethetransmissioncover.
- Unscrew the two screws shown in the
figuretoremovetheairconveyor.
Locking torques (N*m)
Air conveyor screws
11 ÷ 12
-Removethe external transmission
cover.
- Unscrew the 4 fastening screws
showninthe figure to removethe
externalairconveyor.
Air duct filter
-Remove theexternalairconveyor.
-Unscrewthe2fasteningscrewsshown
inthe figuretoremovetheconveyor filter.
Removing the driven
pulley shaft bearing
-Removethetransmissioncover.
-Removetheseegerring.
-Place transmission cover on awood
surface and use the special tool so that
it is adequately supported.
- Pull out the bearing using the special
tool.
N.B.
BELLMUSTBE PLACEDINTOTHE
TRANSMISSIONCOVER,CLOSETO THE
BEARINGSEATANDTHEWOODEN
SURFACE, SINCEWITHOUTBELLTHE
ENTIRECOVERSTRUCTUREWOULD
BEND.
Specific tooling
001467Y002
Driverfor OD73 mmbearing
020376Y
Adaptorhandle
020375Y
28 x 30 mm adaptor
020439Y
17mm guide

12 10/07
Refitting the driven pulley
shaft bearing
-Heat the transmission coverinterior
using the heat gun.
N.B.
BECAREFULNOTTOOVERHEATTHE
COVERASTHISWOULDDAMAGETHE
OUTSIDEPAINTEDSURFACE.
Specific tooling
020151Y
Airheater
Baffle roller
Plastic roller
- Check that the roller does not show
signs of wear and that it turns freely.
- Loosen the retaining bolt using a 13
mmspanner.
-Removethe complete roller with
bearing.
N.B.
IFTHE ROLLERDOESNOTROTATEFREELY,REPLACETHECOMPLETEROLLER.
- Place the bearing onto the special tool
with a little grease to prevent it from
comingout.
-Install thenew bearingusing the
special tool.
N.B.
PROPERLYSUPPORTTHEOUTSIDE
COVERTOPREVENTDAMAGINGTHE
PAINTEDSURFACE.
Specific tooling
020376Y
Adaptorhandle
020358Y
37x40mmadaptor
020439Y
17mm guide
Installation of belt anti-vibration roller
-Install the anti-flapping roller with the lip facing the engine crankcase.
-Tighten the central screw to the prescribed torque.
N.B.
TURNTHEDRIVENAND/ORDRIVINGPULLEYUNTILACORRECTTENSIONINGOFTHE
BELTISOBTAINED.
Locking torques (N*m)
Anti-vibration roller screw
16.7 - 19.6

13 10/07
Removing the driven
pulley
-Remove the clutch bell.
-Removethefixeddrivinghalf-pulley.
-Removethedriven pulley assembly
with the belt.
Removing the clutch
-Toremove theclutch with thedriven
pulley it is necessary to use the special
tool;
-Arrange the tool with the mean pins
screwed in position "E" on the inside;
-Fitthe adapter ring(020444Y010) to
the clutch assembly as shown in the
photograph.
- Install the driven pulley unit onto the
tool inserting the pins into the
ventilationholes;
-Move the rear stop screw in abutment
againstthe fixed driven pulleyas shown
inthe figure.
THETOOLSHOULDBEFIRMLY
SECUREDINAVICEUSINGTHE
SPECIALTOOL.DONOTTIGHTENTHE
REARSCREWTOOMUCHASTHISCOULD
CAUSEANIRREVERSIBLETOOL
DEFORMATION.
USINGTHESPECIAL55-MM
WRENCH,REMOVETHEFASTENING
RINGNUT.
LOOSENTHETOOLSCREWAND
DISASSEMBLETHEDRIVENPULLEY
UNIT,CLUTCH,SPRINGWITHSHEATH.
Specific tooling
020444Y
Tool for fitting/ removing the driven
pulleyclutch.
Inspecting the clutch
drum
- Check that the clutch bell is not worn
ordamaged.
-Measuretheclutchbellinsidediameter.
N.B.
CHECKTHEECCENTRICITYMEASURED:
0.2 MM MAX.
Characteristic
Max. value: 160.5 mm
Standard value: 160.2 mm

14 10/07
- Do not open the masses using tools
topreventa variation in the returnspring
load.
-Remove the 4 guidepins.
-Extractthemoving driven half-pulley.
Removing the driven half-
pulley bearing
- Check that the bushing is free from
wearanddamage;otherwisereplace
thefixeddrivenhalf-pulley.
- Remove the lock ring using pliers.
- Using the special tool inserted through
the roller bearing, pull out the ball
bearing.
N.B.
PROPERLYSUPPORTTHEPULLEYTO
PREVENTDAMAGINGTHETHREADING.
Specific tooling
020376Y
Adaptorhandle
020456Y
Ø 24 mm adaptor
020363Y
20mm guide
Inspecting the clutch
- Check the thickness of the clutch mass friction material.
Characteristic
Minimum thickness permitted:
1 mm
- The masses must not show traces of lubricants. Otherwise, check the driven pulley
unit seals.
N.B.
UPONRUNNING-IN,THE MASSESMUSTEXHIBITACENTRALCONTACTSURFACEAND
MUSTNOTBEDIFFERENTFROMONEANOTHER.VARIOUSCONDITIONSCANCAUSE THE
CLUTCHTO TEAR.
Pin retaining collar
- Extract the collar using 2
screwdrivers.

15 10/07
N.B.
IFYOU NEEDTOOVERHAULTHE BEARINGSONANASSEMBLEDDRIVENPULLEYUNIT,IT
ISNECESSARYTO SUPPORT THEUNITBYTHEBELL
Specific tooling
001467Y002
Driverfor OD73 mmbearing
Inspecting the driven
fixed half-pulley
- Check that the belt contact surface is
freefrom wear.
-Measure the outerdiameter of the
pulleybushing.
Characteristic
Minimum admissible diameter
49.91mm
Standard diameter:
50.00 mm
-Removetheroller bearing using the
specialtool, supporting thefixed half-
pulley with the bell.
Specific tooling
020376Y
Adaptorhandle
020375Y
28 x 30 mm adaptor
020364Y
25mm guide
001467Y002
Driverfor OD73 mmbearing
Inspecting the driven
sliding half-pulley
- Check that the belt contact surface is
freefrom wear.
-Remove the 2inside sealing ringsand
the 2 outside O-rings.
-Measurethemovablehalf-pulley
bushinginsidediameter.
Characteristic
Maximum admissible diameter:
50.05mm
Standard diameter:
50.00 mm
Refitting the driven half-
pulley bearing
-Install a newroller bearing using the
special tool.
N.B.
PLACETHE BEARINGWITHTHE
WRITINGSANDTHEEMBEDDEDOIL
GUARDFACINGOUTWARDS.
-Properly support the half-pulley to
preventdamagingthe threading.
Ifyouare working on thedriven pulley
unit fully assembled, use the special
tool.
Specific tooling
020478Y
Punchfor driven pulley roller casing
001467Y002
Driverfor OD73 mmbearing
-0,015
-0,035
+0,035
0,00

16 10/07
- Install a new ball bearing using the
special tool.
Specific tooling
020376Y
Adaptorhandle
020477Y
37mm adaptor
020363Y
20mm guide
- Insert the seeger lock ring.
- Install the half-pulley on the bushing being careful not to damage the top sealing
ringduringthe introduction.
- Make sure the pins and collar are not worn, reassemble the pins and collar.
- Using a bent beak greaser, lubricate the driven pulley unit with about 10 gr. of
grease, this operation should be carried out through one of the two holes into the
bushing to obtain the exit of the grease from the opposite hole. This operation is
necessaryto avoid the presenceof grease beyondthe O-rings.
Recommended products
Greaseforthe tone wheelrevolvingring
Soap-basedlithiumgreasecontaining NLGI 2 Molybdenum disulphide;ISO-L-
XBCHB2,DINKF2K-20
Inspecting the clutch
spring
-Measure the length of the spring, while
it is relaxed.
Characteristic
Standard length:
125.5mm
Admissible limit after use:
120mm
Refitting the clutch
-Preparethe special tool asforremoval;
-Preassemble the driven pulleyunit
with the drive belt according to its
directionofrotation;
-Insert the driven pulley unit, the spring
with sheath and clutch into the tool.
Specific tooling
020444Y
Tool for fitting/removingthedrivenpulley
clutch
-Compressthe spring and insert the
clutchonthedrivenpulleybushing.
N.B.
BECAREFULNOTTODAMAGETHESHEATHORTHEBUSHINGTHREADEDEND.
- Tighten the ring nut by hand and complete the tightening using the special wrench
tothe prescribed torque.
Specific tooling
020444Y
Tool for fitting/ removing the driven pulley clutch
-To facilitatereassemblyon the engine, turn themoving driven pulleyand insert the
beltonto the smaller diameter.
Locking torques (N*m)
Clutch ring nut
65 - 75
Refitting the driven pulley
-Insert thenew oilguards
-Insert the new O-rings
N.B.
O-RINGSAREOF TWOSIZES.THELARGE
ONEISINSTALLEDONTHEMACHINING
ENDRADIUS,ATTHEBASEOFTHEHALF-
PULLEY.

17 10/07
Refitting the driven pulley
- Install the driven pulley assembly with
belt.
Drive-belt
- Check that the driving belt is not
damaged.
- Check the width of the belt.
Characteristic
Minimum width
27.5mm
Overall width
28.7mm
Removing the driving
pulley
- Using a 27 mm wrench, turn the
central pulley nut to horizontally align
the central inside holes and install the
special tool.
Specific tooling
020474Y
Drivingpulleylock wrench
- First fit the 2 retainer clamps of the
special tool onto the pulley so that the
splinesarecompletely engaged.
- Then, insert the tool so as to insert
the stud bolts on the ring into the holes
obtained onto the tool itself.
- Tighten the two tool fixing screws,
alsomanually.
- Loosen the central nut.
-Removethe spring washer andthe flat
washer.
-Removethefixeddrivinghalf-pulley.
-Removethebushingconnection
washer.
-Movethebeltdownwards.
- Suitable support the roller contrast
andextractthemobile driving half-pulley
withtherelevant bushing and therear
washer,being careful notto make the
rollers come out.
-Measure the pulley sliding bushing
outsidediameter shown in thefigure.

18 10/07
-Measure the pulley sliding bushing
outsidediameter shown in thefigure.
Characteristic
Minimum admissible diameter
Ø 29.95 mm
Standard diameter:
Ø29.959 mm
- Check that the rollers are not
damagedorworn.
Characteristic
Minimum admissible diameter
Ø 24.5 mm
Standard diameter:
Ø 24.9 mm
-Check the guide shoes for the variator
back-platearenot worn.
-Check thewear of the roller housings
and of the belt contact surfaces on both
pulleyhalves.
Refitting the driving pulley
Installing the roller container
- Install the spacer with the internal
chamferfacingtowards the inside.
- Position the rollers on the half-pulley
as shown in the figure.
- The closed side must rest on the
insidethrust face of the roller container.
-Assembly the half-pulley with the roller
contrast plate and sliding blocks.
Inspecting the rollers case
- Check that the inside bushings shown in the figure are not worn and measure the
insidediameter.
DONOTLUBRICATEORCLEANTHEBUSHINGS
Characteristic
Maximum admissible diameter:
30.12mm
Standard diameter:
30.021mm

19 10/07
-Insert the half-pulleyon the
crankshaft.
-Insert the spacer bushing.
Installing the fixed driving half-
pulley
- Insert the spacer.
-Installthefixed driving half-pulley and
check that it is in contact with the
spacerand with theguide bushing of
themovingdrivingpulley.
-Removethe flat washer andthe spring
washeras shown inthe figure.
- Insert the nut in the original position
(nut side in contact with the belleville
washer).
-Turn thecentralpulleynutto horizontally
aligntheholes and install the specialtool.
N.B.
CHECKTHATTHESTOPWRENCHTOOLIS
EASILYINSERTEDINTOTHEPULLEYANDIN
THEENGINECRANKCASE.
Specific tooling
020474Y
Drivingpulleylock wrench