Malaguti 500 cc 4T User manual

1 10/07

MALAGUTI S.p.A.

Via Emilia 498, 40068 - San Lazzaro di Savena (BO) - ITALY

Tel. 051.62.24.811 - Fax 051.69.47.782

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 is available in the SPARE PARTS CATALOGUE and in the SERVICE MANUAL - FRAME AND RUNNING GEAR section.

• It is important to read all the general information before going through the manual to the specific topics and the maintenance operations to be carried out on the engine in order

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 to adhere strictly to the following instructions. Any operation carried out carelessly or not carried out at all may, damage the engine or simply lead to complaints.

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.

2 10/07

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 with attention to the customer’s opinion and complaints about the engine operation, asking specific questions in order to have a complete understanding 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

components that needs repairing.

• Prepare the components that are likely to be replaced and all the original spare parts you may need.

• Mark the components that may be mis-placed during re-assembly operations.

• 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-end box wrenches by “pulling” and not “pushing”.

• For operations requiring two mechanics, make sure that the various steps to be performed by each of them are clearly defined and co-ordinated beforehand.

• Make sure that each component has been properly mounted before proceeding 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.

3 10/07

DESCRIPTION P.

SPECIFICATIONS 4

TIGHTENING TORQUES 5

AUTOMATIC TRANSMISSION 10

Transmission cover 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

Removing the driven half-pulley bearing 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

Removing the driving pulley 17

Inspecting the rollers case - Refitting the driving pulley 18

Refitting the transmission cover 20

END GEAR 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

FLYWHEEL COVER 26

Removing the hub 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.

FLYWHEEL AND 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

Removing the 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

4 10/07

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

5 10/07

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

CRANKCASE AND 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

6 10/07

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

This section provides the main information for scooter servicing.

Assembly clearances cylinder - piston assy

HEIGHT TO MEASURE PISTON AND CYLINDER

CYLINDER - PISTON

N.B.

THE PISTON MUST BE INSTALLED WITH THE ARROW FACING TOWARDS THE OUTLET

SIDE, THE PISTON RINGS MUST BE INSTALLED WITH THE WORD "TOP" OR THE

STAMPED MARK FACING UPWARDS.

COUPLING CATEGORIES

+0,018

-0,01

±0,014

7 10/07

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

Rings/housing coupling clearances:

Carefully clean the sealing ring housings.

Place a thickness gauge between the ring and the hou-

sing as shown in the drawing and check the 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

Magnetic support for dial gauge

8 10/07

Crankshaft-crankcase axial clearance (H)

0.1 ÷ 0.405 mm (when cold)

Compression ratio

10.5: 1

AXIAL CLEARANCE BETWEEN CRANKSHAFT AND CONNECTING ROD

The value of the “M” fixture axial clearance is acceptable within the range of

0.20 ÷ 0.60 mm

Description Dimensions

Transmission-side shoulder E = 1 ± 0,025

Half-shaft, transmission side F = 20,9

Connecting rod G = 22

Flywheel side half-shaft H = 19,6

Flywheel-side shoulder I = 1,8 ± 0,025

Complete crankshaft L = 65,5

0

-0.05

-0.10

-0.15

0

-0.05

+0.10

-0.05

9 10/07

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" IS A PROTRUSION OR RECESS VALUE OF THE PISTON

CROWN WITH RESPECT TO THE CYLINDER PLANE.

DISTANCE "A" HELPS DETERMINE THE THICKNESS OF GASKET "B" THAT

HAS TO BE FITTED TO THE CYLINDER HEAD IN ORDER TO RESTORE

COMPRESSION RATIO. BASE GASKET "B" MUST BE THICKER THE MORE

THE PLANE FORMED BY THE PISTON TOP PROTRUDES FROM THE PLANE

FORMED BY THE CYLINDER HEAD. ON THE OTHER HAND, THE MORE THE

PISTON TOP IS RECESSED INTO THE CYLINDER TOP PLANE, THE SMALLER

THE GASKET THICKNESS.

N.B.

VALUES INDICATED WITH "-" REFER TO PISTON CROWN RECESSES WITH

RESPECT TO THE CYLINDER PLANE.

N.B.

DISTANCE "A" MUST BE MEASURED WITHOUT 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.

- Remove the four M8 screws.

- Remove the transmission cover.

- Check that the bearing rotates freely,

otherwise replace it.

Automatic

transmission

Transmission cover

- Loosen the 4 fastening screws

- Extract the outside plastic

transmission cover.

- Using a screwdriver, remove the driven

pulley axle cover near the bottom of the

cap.

- Loosen the driven pulley shaft fastening

nut using a misaligned wrench and

prevent the pulley shaft rotation using a

machine hexagon bush.

- Remove the nut and the two washers.

N.B.

DUE TO THE HIGH TIGHTENING TORQUE,

USING DIFFERENT WRENCHES - SUCH AS

A CONVENTIONAL POLYGONAL BUSH -

MAY DAMAGE THE HEXAGON OBTAINED ON

THE SHAFT OR BREAK THE BUSH ITSELF.

11 10/07

Air duct

- Remove the transmission cover.

- Unscrew the two screws shown in the

figure to remove the air conveyor.

Locking torques (N*m)

Air conveyor screws

11 ÷ 12

- Remove the external transmission

cover.

- Unscrew the 4 fastening screws

shown in the figure to remove the

external air conveyor.

Air duct filter

- Remove the external air conveyor.

- Unscrew the 2 fastening screws shown

in the figure to remove the conveyor filter.

Removing the driven

pulley shaft bearing

- Remove the transmission cover.

- Remove the seeger ring.

- Place transmission cover on a wood

surface and use the special tool so that

it is adequately supported.

- Pull out the bearing using the special

tool.

N.B.

BELL MUST BE PLACED INTO THE

TRANSMISSION COVER, CLOSE TO THE

BEARING SEAT AND THE WOODEN

SURFACE, SINCE WITHOUT BELL THE

ENTIRE COVER STRUCTURE WOULD

BEND.

Specific tooling

001467Y002

Driver for OD 73 mm bearing

020376Y

Adaptor handle

020375Y

28 x 30 mm adaptor

020439Y

17 mm guide

12 10/07

Refitting the driven pulley

shaft bearing

- Heat the transmission cover interior

using the heat gun.

N.B.

BE CAREFUL NOT TO OVERHEAT THE

COVER AS THIS WOULD DAMAGE THE

OUTSIDE PAINTED SURFACE.

Specific tooling

020151Y

Air heater

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

mm spanner.

- Remove the complete roller with

bearing.

N.B.

IF THE ROLLER DOES NOT ROTATE FREELY, REPLACE THE COMPLETE ROLLER.

- Place the bearing onto the special tool

with a little grease to prevent it from

coming out.

- Install the new bearing using the

special tool.

N.B.

PROPERLY SUPPORT THE OUTSIDE

COVER TO PREVENT DAMAGING THE

PAINTED SURFACE.

Specific tooling

020376Y

Adaptor handle

020358Y

37x40 mm adaptor

020439Y

17 mm 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.

TURN THE DRIVEN AND/OR DRIVING PULLEY UNTIL A CORRECT TENSIONING OF THE

BELT IS OBTAINED.

Locking torques (N*m)

Anti-vibration roller screw

16.7 - 19.6

13 10/07

Removing the driven

pulley

- Remove the clutch bell.

- Remove the fixed driving half-pulley.

- Remove the driven pulley assembly

with the belt.

Removing the clutch

- To remove the clutch with the driven

pulley it is necessary to use the special

tool;

- Arrange the tool with the mean pins

screwed in position "E" on the inside;

- Fit the 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

ventilation holes;

- Move the rear stop screw in abutment

against the fixed driven pulley as shown

in the figure.

THE TOOL SHOULD BE FIRMLY

SECURED IN A VICE USING THE

SPECIAL TOOL. DO NOT TIGHTEN THE

REAR SCREW TOO MUCH AS THIS COULD

CAUSE AN IRREVERSIBLE TOOL

DEFORMATION.

USING THE SPECIAL 55-MM

WRENCH, REMOVE THE FASTENING

RING NUT.

LOOSEN THE TOOL SCREW AND

DISASSEMBLE THE DRIVEN PULLEY

UNIT, CLUTCH, SPRING WITH SHEATH.

Specific tooling

020444Y

Tool for fitting/ removing the driven

pulley clutch.

Inspecting the clutch

drum

- Check that the clutch bell is not worn

or damaged.

- Measure the clutch bell inside diameter.

N.B.

CHECK THE ECCENTRICITY MEASURED:

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

to prevent a variation in the return spring

load.

- Remove the 4 guide pins.

- Extract the moving driven half-pulley.

Removing the driven half-

pulley bearing

- Check that the bushing is free from

wear and damage; otherwise replace

the fixed driven half-pulley.

- Remove the lock ring using pliers.

- Using the special tool inserted through

the roller bearing, pull out the ball

bearing.

N.B.

PROPERLY SUPPORT THE PULLEY TO

PREVENT DAMAGING THE THREADING.

Specific tooling

020376Y

Adaptor handle

020456Y

Ø 24 mm adaptor

020363Y

20 mm 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.

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.

Pin retaining collar

- Extract the collar using 2

screwdrivers.

15 10/07

N.B.

IF YOU NEED TO OVERHAUL THE BEARINGS ON AN ASSEMBLED DRIVEN PULLEY UNIT, IT

IS NECESSARY TO SUPPORT THE UNIT BY THE BELL

Specific tooling

001467Y002

Driver for OD 73 mm bearing

Inspecting the driven

fixed half-pulley

- Check that the belt contact surface is

free from wear.

- Measure the outer diameter of the

pulley bushing.

Characteristic

Minimum admissible diameter

49.91 mm

Standard diameter:

50.00 mm

- Remove the roller bearing using the

special tool, supporting the fixed half-

pulley with the bell.

Specific tooling

020376Y

Adaptor handle

020375Y

28 x 30 mm adaptor

020364Y

25 mm guide

001467Y002

Driver for OD 73 mm bearing

Inspecting the driven

sliding half-pulley

- Check that the belt contact surface is

free from wear.

- Remove the 2 inside sealing rings and

the 2 outside O-rings.

- Measure the movable half-pulley

bushing inside diameter.

Characteristic

Maximum admissible diameter:

50.05 mm

Standard diameter:

50.00 mm

Refitting the driven half-

pulley bearing

- Install a new roller bearing using the

special tool.

N.B.

PLACE THE BEARING WITH THE

WRITINGS AND THE EMBEDDED OIL

GUARD FACING OUTWARDS.

- Properly support the half-pulley to

prevent damaging the threading.

If you are working on the driven pulley

unit fully assembled, use the special

tool.

Specific tooling

020478Y

Punch for driven pulley roller casing

001467Y002

Driver for OD 73 mm bearing

-0,015

-0,035

+0,035

0,00

16 10/07

- Install a new ball bearing using the

special tool.

Specific tooling

020376Y

Adaptor handle

020477Y

37 mm adaptor

020363Y

20 mm guide

- Insert the seeger lock ring.

- Install the half-pulley on the bushing being careful not to damage the top sealing

ring during the 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

necessary to avoid the presence of grease beyond the O-rings.

Malaguti 500 cc 4T User manual

Malaguti 500 cc 4T User manual

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