Gilera SATURNO BIALBERO 350, SATURNO BIALBERO 500 Workshop Manual

WORKSHOP MANUAL

SATURNO BIALBERO

350-500

Reproduced by

OWNERS CLUB

OF BRITAIN

from information obtained from original or copied

manuals originally issued by

Piaggio/Gilera

Whilst every care has been taken to ensure
accuracy of the contents, I Gotta Gilera does not
accept any liability of any type due to any errors or
omissions, and use of this manual will denote
acceptance of this condition.

NOTES:

In addition to this workshop manuals texts and pictures transcribed from original
Piaggio/Gilera manuals, there is included a section on the various known faults with
which the Saturno is prone to suffer. Whilst these faults were obviously not included
in the original official manuals, we believed they should be a part of any publication
dealing with Saturno maintenance.

There have also been a couple of “obvious” errors within the original manuals and
these have been copied “as is” into this manual, but a note has been added with
what we believe to be the correct details.

You will also find at the very rear of this manual, a few general maintenance tips,
which you may find useful.

If you find any other errors, please email [e-mail] so that this manual
can be updated to be as accurate as is possible.

INDEX

General information - Known faults
Special tools
Maintenance

ENGINES

Working procedures
Engine removal/installation
Generator - Timing belt - Gearbox selector
Cylinder head - Valvetrain components
Cylinder - Piston
Clutch - Primary drive - Oil pump
Crankcase - Gearbox - Crankshaft components

FRAMES

Working procedures
Front Wheel
Front suspension - Steering
Rear Suspension - Rear wheel
Brakes

ELECTRICAL SYSTEM

Battery - Charging circuit
Ignition system
Electric starter
Switches - Horn - Lights - Rear mudguard - Exhaust
Trouble shooting
Circuit diagram

Section

1
2
3

4
5
6
7
8
9

10

11
12
13
14
15

16
17
18
19
20
21

GENERAL INFORMATION 1

SUB INDEX

Known faults
Safety procedures
Maintenance procedures
Model Identification
Technical data
Torque wrench settings
Engine overhaul data
Cables and wire passage

Section - Page

1 - 1
1 - 2
1 - 2
1 - 2
1 - 3
1 - 4
1 - 5

1 - 6

1

KNOWN FAULTS 1 - 1

Fan touches Radiator. Remove tank, look down back of radiator &

check that fan shroud has about 3mm (1/8”) clearance. The fan
mountings are slotted but if there is not enough adjustment, trim the front
of the shroud.

Side stand bolts come loose/fall out. Remove stand and check
mounting surfaces are clean & flat. Refit stand with ‘Loctite’ on mounting
bolt threads. Check stand regularly.

Fuel tank touches frame. Tank is rubber mounted and can move,
touch the frame tubes (along the bottom near the front) and also the rear
mounting rubbers can be a problem, both of which can result in leaks
occurring. Remove the metal tube spacers from the rear rubbers and
check their lengths. If one is longer, file it down to the length of the
shorter one. Placing a washer under the front mountings will make a big
difference.

Starter bolts work loose. ’Loctite’ on the bolt threads and check
occasionally.

Rear suspension linkage gets all the bad weather. Put axle stands
under footrests to support bike with rear wheel off the ground. Take
weight of wheel/swinging arm and remove bolts from rising rate link (3
point bracket attached to bottom of rear suspension unit) Grease
thoroughly and replace. This should be done every 6 months.

Rising rate bottom link bolt can seize. Remove rising rate link (see
above), two of the bearings are self aligning ball joints, these just need
some grease either side to keep the wet out. The lower long bearing
needs to be cleaned and greased as well as possible as it is vulnerable
and can easily rust.

Long rear engine bolts can seize. Remove the bolts one at a time,
clean off any corrosion and coat them in ‘Copper Slip’ or grease before
refitting. Torque 30Nm.

Seat retaining lugs snap off. No easy solution but metal reinforcing
brackets can be made.

1 - 1

SAFETY PROCEDURES 1 - 2

Whenever working with the engine running, never work in closed areas; always
have the area well ventilated due to the toxic gases (carbon monoxide) contained in
the exhaust.

The battery’s electrolyte contains sulphuric acid. Always protect the eyes, clothes
and skin. If electrolyte gets into the eyes, flush thoroughly and seek medical
assistance promptly.

Petrol is highly flammable and in certain conditions even explosive. Never smoke in
work areas; avoid sparks or flames.

The battery produces hydrogen which is highly explosive. Never smoke around a
battery and avoid sparks and flames, especially while charging.

MANTENANCE PROCEDURES 1 - 2

Always use original GILERA spare parts and recommended lubricants. The use of
non-original parts or parts not conforming to Gilera specifications may result in
damage to the motorcycle.

Always use the special tools designed specifically for this motorcycle.
Always use new gaskets, O-rings, split pins and safety plates when reassembling.
Always tighten nuts or bolts starting with those of greater diameter or found

internally; tighten in a diagonal sequence in 2 or 3 passes and to the recommended
torque unless otherwise noted.

Clean components with non-flammable solvents or at least solvents having a high
flash point. Lubricate working surfaces prior to reassembly.

After reassembly, make sure that all components are installed and operate properly.
Always use metric tools when working on this motorcycle; metric nuts and bolts are

not interchangeable with the British sizes. The use of either non-metric tools and/or
nuts and bolts may cause damage to the motorcycle.

Arrange all electrical wires as indicated in the “Cables and wire passage”
paragraph.

MODEL INDENTIFICATION 1 - 2

Frame and engine numbers are stamped on the Manufacturer’s plate (fig. 1). The
frame number is also stamped on the frame (fig. 2), and the engine number and
size are stamped on a plate found at the rear of the engine (fig. 3).

The carburettor part number is found on the side of the carburettor (fig. 4).

1 - 2,1

MODEL IDENTIFICATION 1 - 2

1 - 2 ,2

TECHNICAL DATA 1 - 3

DESCRIPTION
DIMENSIONS

Overall length
Overall width
Overall height
Wheelbase
Seat height
Foot pedal height
Dry weight

FRAME

Triangulated tubular steel space frame
Steering column angle

Forestroke
Front suspension

- Marzocchi telescopic hydraulic fork

- Stroke

- Stanchion diameter

- Oil capacity (each side)
Rear suspension

- Marzocchi monodamper powerdrive progressive

-Stroke
Wheels

- Front:

- Tyre size

- Pressure
Above believed to be incorrect, we recommend

- Rear:

- Tyre size

- Pressure
Above believed to be incorrect, we recommend

Brakes

- Front, floating disc with hydraulic double piston

- Disc diameter

- Rear, floating disc with hydraulic single piston

- Disc diameter
Fuel tank capacity

Fuel tank reserve

350cc - 500cc

2030 mm

730 mm
1170 mm
1410 mm

790 mm

360 mm

145 kg

24.30 30’

89.7 mm

120 mm

40 mm
310 cc

130 mm

3.00 X 17”
110/70-17

1.7 bar

2.1 bar 30 psi

4.00 X 17”
140/70-17

1.7 bar

2.3 bar 33 psi

300 mm

240 mm

20ltrs 4.4galls

1.5ltrs .33galls

1 - 3,1

TECHNICAL DATA 1 - 3

ENGINE

Single cylinder, 4 stroke, vertical cylinder
Bore X stroke
Displacement
Compression ratio
Cylinder compression (use special tool 19.1.20524)
New engine
Over 5,000km
BHP

Torque at 5,500 rpm

Valvetrain - 2 belt driven overhead camshaft
Lubricating system - forced, inner gear driven pump

Oil capacity (10w40 semi synthetic)
Cooling system - permanent coolant with recirculating

pump and by-pass thermostat
Coolant capacity (Silkolene Pro-cool etc)

Air filter - sponge type
Intake valve diameter

Exhaust valve diameter
Valve clearance (cold): clearance between camshaft
and rocker arm
Intake (cold)
Exhaust (cold)

TRANSMISSION

Clutch - wet, multiplate
Primary drive
Gearbox with straight-tooth gears and claw couplings
Gear ratio
1st gear
2nd gear
3rd gear
4th gear
5th gear

Final drive

350cc - 500cc

80 X 69.4 - 92 X 74

348.8 cc - 491.9 cc
9,5:1 - 9,8:1

9 ÷ 11

8 ÷10

24kW(33 hp) - 32kW(44 hp)

a/at 7500 - a/at 7000

g/1’ -rpm

33Nm(3.3kgm)-47Nm(4.7kgm)

a/at 6250 - a/at 6000

g/1’ -rpm

2.2 ltrs

1.3 ltrs

28.4 mm - 31 mm

25.5 mm - 28mm

0.05mm

0.10mm

33/77

13/31
18/28
21/24
23/21
25/19

15/48 - 15/43

1 - 3,2

TECHNICAL DATA 1 - 3

CARBURETTOR

Throttle valve
Needle jet

Fuel nozzle
Max jet
Idle jet
Choke jet
Pump jet
Needle notch
Fuel nozzle
Throttle valve
Float
Weight
Air mixture screw
RPMs at idle

ELECTRICAL SYSTEM

Ignition - electronic capacitive discharge
Ignition timing Fixed
Variable
Alternator - three phase AC alternator
Battery capacity
Kick starting
Electrical starting
Standard spark plug (Champion)
Electrode gap
Fuses
Starter motor
Headlamp
Driving lamp
Tail/stop lamp
Turn signal lamp
Instrument lamp
Warning indicator lamp

350cc - 500cc

Dell‘ Orto

PHF36PS - PHM40VS

K54 - K4

3a tacca-3rd notch - 2a tacca-2nd notch

AB262 - AB265

128 - 138
58 - 53
40 - 40

Ø 1.1

5C55-3/5

AB262 - AB265

5.5

14g - 10g

1 giro-rev 1300÷1400-1.5 giro-rev 1300÷1400

1300÷1400 (both)

7°

30° at 4,500 g/1’-rpm

180w

14 Ah

3 Ah
14 Ah
A5YC

0.6 ÷ 0.7 (both)
15 Amp

0.65 kW - 0.80 kW
40/45 Watt

5 watt

5/21 watt

10 watt

2 watt

1.2 watt

1 - 3,3

TECHNICAL DATA 1 - 4

TORQUE WRENCH SETTINGS

* = Lubricate the thread with oil

+ = Copper slip on thread

Engine

Cylinder head, cylinder head cover, cylinder fixing nuts
Cam pulley bolts
Spark plug +
Crankshaft gearing bolt *
Countershaft gearing bolt *
Free wheel bolt *
Clutch bolt *
Flywheel magneto bolt *
Chain drive sprocket bolt
Starter motor mounting bolts
Kick starter clamp bolt
Big end bolts
Crankcase mounting bolts
Belt tightening pulley nut
Draining oil plug
Cooling fan thermostatic switch
Thermistor
Oil pressure indicator

Frame

Front engine support
Rear top engine support
Rear lower engine support
Engine support on head
Lower plate mounting bolts
Top plate mounting bolts
Damper mount
Rear fork mount
Suspension connecting rod support to frame
Suspension connecting rod / lever mount
Suspension / damper lever mount
Suspension / rear fork lever mount
Front calliper
Front brake disk
Rear calliper
Rear brake disc on flange
Rear wheel flange
Rear sprocket mounting bolts
Front wheel spindle
Spindle fastening bolts on fork
Rear wheel spindle
Eccentric locking nuts

350cc + 500cc

(both)

32-35 Nm

30 Nm

12-15 Nm

40 Nm
40 Nm
40 Nm
40 Nm
40 Nm
60 Nm

7-9 Nm
18-20 Nm
28-32 Nm

7-9 Nm
28-30 Nm
12-15 Nm
20-22 Nm

8-10 Nm

15-17 Nm

25-30 Nm
25-30 Nm
30-35 Nm
25-30 Nm
25-30 Nm
25-30 Nm
40-45 Nm
55-60 Nm
50-55 Nm
50-55 Nm
50-55 Nm
50-55 Nm
44-48 Nm
18-20 Nm
16-18 Nm

9-11 Nm
18-20 Nm
48-52 Nm
50-60 Nm

9-11 Nm
50-60 Nm
20-22 Nm

1 - 4

ENGINE OVERHAUL DATA 1 - 5

Piston/cylinder clearance
Main bearings radial clearance
Connecting rod bearings radial clearance
Crankshaft axial clearance
Big end axial clearance
Gudgeon pin/piston clearance
Gudgeon pin/small end clearance
Bushings/small end clearance
Main bearings to seat clearance
Valve guide/cylinder head clearance
Valve stem/guide clearance
Intake
Exhaust
Gudgeon pin diameter
Main journal diameter
Cylinder bore
Piston diameter
Cam height (theoretical)
Oil pump rotors axial clearance
Selector drum axial clearance
Inner valve spring free length
Outer valve spring free length
Clutch springs free length
Clutch plate thickness
Camshaft bolts radial clearance
Axle/rocker arm radial clearance
Piston ring gap
1st and 2nd ring
scraper ring
Rings axial clearance
1st and 2nd ring
scraper ring
Oil pressure
Water thermostat opens at
Water thermostat fully opens at
Cooling fan enable temperature
Valve clearance (between camshaft and rocker arm) ?
Intake (cold)
Exhaust (cold)

350cc - 500cc

0.030 ÷ 0.042 mm

0.030 ÷ 0.059 mm

0.017 ÷ 0.060 mm

0.05 ÷ 0.25 mm

0.15 ÷ 0.25 mm

0.000 ÷ 0.008 mm

0.015 ÷ 0.030 mm

0.049 ÷ 0.087 mm

0.084 ÷ 0.140 mm

0.030 ÷ 0.066 mm

0.012 ÷ 0.042 mm

0.025 ÷ 0.055 mm

40.018÷40.030 mm

39.987÷40.000 mm
see table below
see table below

36.18 mm

0.025 ÷ 0.060 mm

0.07 ÷ 0.42 mm

37.6 ÷ 38.6 mm

38.7 ÷ 39.7 mm

38.5 mm

2.9 ÷ 3.0 mm

0.035 ÷ 0.070 mm

0.016 ÷ 0.052 mm

0.30÷0.50 - 0.40÷0.65mm

0.25÷0.50 - 0.30÷0.60mm

0.035 ÷ 0.072 mm

0.025 ÷ 0.062 mm

4 bar at 5,500 g/1’ rpm

750C
850C

92 ± 30C

0.05 mm

0.10 mm

350 Cylinder 500

80.000÷80.006 - 92.000÷92.006

80.006÷80.012 - 92.006÷92.012

80.012÷80.018 - 92.012÷92.018

1 - 5

350 Piston 500

79.964÷79.970 - 91.964÷91.970

79.970÷79.976 - 91.970÷91.976

79.976÷79.982 - 91.976÷91.982

Class

A
B
C

PISTON/CYLINDER MATCHING CHART (value in mm)

CABLES AND WIRE PASSAGE 1 - 6

Point out the passage of each cable and wire (figs. 5-6-7-8-9).

1 - 6

SPECIAL TOOLS 2

Valve guide oil ring

installation punch

19.1.20502

Con-rod small end bushing

extraction punch

19.1.20506

2.1

Flywheel puller

19.1.20501

Con-rod small end bushing

installation punch

19.1.20505

Puller for steering bearing lower race

19.1.20109

Camshaft pulley blocking tool

19.1.20504

Sprocket locking wrench

19.1.20086

Camshaft oil ring installation punch

19.1.20503

SPECIAL TOOLS 2

Main journal bearing extraction ring

(clutch side)

19.1.20510

Timing drive gear puller

19.1.20514

2.2

Pad for crankshaft and

flywheel puller

19.1.20513

Piston support

19.1.20512

Main journal bushing extraction punch

19.1.20507

Main journal bearing extraction ring

(ignition side)

19.1.20511

Main journal bearing installation punch

(clutch side)

19.1.20508

Main journal bearing installation punch

(ignition side)

19.1.20509

SPECIAL TOOLS 2

Mounted flywheel blocking tool

19.1.20521

Oil seal installation sleeve

19.1.20525

2.3

Oil filter removal spanner

19.1.20520

Compression check tool

19.1.20524

Valve spring compression tool

19.1.20519

Valve guide extraction/installation punch

19.1.20523

Drive gear blocking tool

19.1.20515

Valve clearance adjustment tool

19.1.20522

SPECIAL TOOLS 2

Reamer set for valve seats

19.1.20529

Punch

19.1.20566

2.4

Complete roller cage extractor

19.1.20528

Chain slack tool

19.1.20565

Engine support base

19.1.20527

Battery charge density meter

19.1.20564

Engine support

19.1.20526

Pin sliding punch

19.1.20530

SPECIAL TOOLS 2

2.5

Exhaust manifold spring removal tool

19.1.20551

Clutch collets tool

19.1.20540

Complete tool kit

19.1.20563

MAINTENANCE 3

SUB INDEX

Maintenance programme
Instrument panel removal
Fuel passages
Carburettor
Settings
Setting engine speed at idle
Air filter
Valve clearance
Cylinder compression
Engine oil and filter replacement
Spark plug
Throttle control
Clutch
Drive chain
Chain replacement
Rear brake pedal height adjustment
Gearshift lever height adjustment
Foot pedals damper bushings replacement
Trouble shooting
Engine oil replacement
Clutch transmission cylinder on the engine

Section - Page

3 - 1
3 - 2
3 - 2
3 - 2
3 - 3
3 - 3
3 - 3
3 - 3
3 - 4
3 - 4
3 - 4
3 - 5
3 - 5

3 - 5
3 - 6
3 - 6
3 - 6
3 - 6
3 - 6
3 - 7
3 - 8

MAINTENANCE 3 - 1

MAINTENANCE PROGRAMME (*) check every 500 km

3 - 1

Tightening the engine bolt
Tightening the cylinder head bolts
Valve clearance control
Timing belt tension check
Timing belt replacement
Decompression check
Engine compression check
Engine idle speed adjustment
Spark plug check
Spark plug replacement
Engine oil replacement
Oil filter replacement
Air filter check and cleaning
Air filter replacement
Liquid check and fill up
Rear wheel flexible coupling check
Brake and clutch check and adjustment
Sprocket, brake calliper and disc, wheel
spindle, chain pinion mounting bolts (*)
Chain check, adjustment, lubrication (if
necessary, replace the whole drive) (*)
Brake pads and blocks check, replace if req’d
Fork oil replacement
Fork pivot joint tightening check
Steering bearing play check and lubrication
Battery charge/electrical system efficiency
Tyre pressure check

X

-

X

­X
X
X
X

­X
X
X

­X
X

­X

X
X

X
X
X
X
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­X
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X

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X

­X
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X
X

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­X
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X

X
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X

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X

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X

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X
X
X

km

24

th

20

th

16

th

12

th

8
th

4
th

500

to

1 th

PROGRAMMED OPERATIONS

INTENTIONALLY BLANK

MAINTENANCE 3 - 2

INSTRUMENT PANEL REMOVAL

Remove Fairing.
Remove headlamp.
Remove speedometer cable.
Disconnect tachometer cable.
Remove the 3 instrument mounting nuts.
Disconnect electrical connectors.
Remove instrument assembly (fig. 1).

FUEL PASSAGES

Check all the fuel lines and replace any component that shows signs of
damage, wear or leakage (fig. 2). With the 500cc model, be careful not to
crush the air intake that feeds the max jet.

CARBURETTOR (fig. 3)
Removal

Remove seat.
Close fuel cock and remove tank.
Disconnect throttle cable, starter and remove supply hose.
Loosen the clamps on both filter side and intake manifold.
Remove carburettor.

Overhaul

Loosen the two mounting screws, remove the carburettor top and pull off
the throttle valve complete with needle jet. (fig. 4).
Loosen the lower bowl plug and remove bowl (fig. 5).
Remove the jets, nozzle, float, needle valve and disassemble the
accelerator pump.
Inspect the carburettor body and fuel channels; wash with kerosene or
appropriate solvent if dirty. Blow into the channels with compressed air.
Examine the condition of the float, needle valve and its seat, throttle
valve, jet needle and the accelerator pump membrane. Replace any
component if there are signs of deformations, scratches or other damage.
In the event of damage to the needle valve, replace the seat also. Note
the springs and balls found under the accelerator pump jets.
Reassemble carburettor in reverse order of disassembly.

Note: Make sure the throttle valve opens fully prior to reassembly.

3 - 2,1

MAINTENANCE 3 - 2

3 - 2,2

MAINTENANCE 3 - 3

ADJUSTMENTS
Fuel level

Turn over carburettor and let float rest on the needle valve’s damper
spring without pressing.
Check distance between bowl gasket seat and uppermost edge of the float
with proper gauge. Float level = 24 ± 2 mm
Adjustment is made by bending slightly the float tongue.

Engine speed at idle

Check and adjust idle after having made the necessary engine
adjustments.
The engine must be warm in order to set it correctly.
Turn idle adjuster screw until reaching the recommended engine speed.
RPMs at idle 1300 ÷ 1400 rev/min.

AIR FILTER

Remove the 4 air filter box lid screws after removing the seat.
Remove the filter element from the filter box (fig. 6).
Wash the filter element in a non-flammable solvent, then wring it or let dry.
NEVER use petrol or low flash point solvents to wash the element.
Immerse element in lubricating oil, then squeeze it to remove excess oil.
If filter element is worn, replace with new element.
Remount element in its filter box.
Replace filter box lid.

VALVE CLEARANCE

Check valve clearance with engine cold.
Remove fuel tank.
It is recommended to remove the 2 control units and ignition coil to have
more working space.
Remove the spark plug and ignition cover (fig. 7).
Turn crankshaft to get piston at TDC.
Check residual clearance between camshaft and rocker arm with feeler
gauge. (intake valve 0.05 mm, exhaust valve 0.10 mm)
To set clearance, loosen the lock nut and turn the adjusting screw to get a
slight drag on the feeler gauge (fig. 8); hold screw steady and tighten the
lock nut . (torque wrench setting: 10 ÷ 12 Nm)
Check clearance after tightening the lock nut.
Assemble components in reverse order of disassembly.

3 - 3,1

MAINTENANCE 3 - 3

3 - 3,2

MAINTENANCE 3 - 4

CYLINDER COMPRESSION

Warm up engine.
Stop engine and remove spark plus (remove tank if necessary).
Insert compression gauge (19.1.20524) in spark plug hole. Turn throttle
fully open and turn engine over with the electric starter until the gauge
measures the highest value.

Low compression may be caused by:
Incorrect valve clearance
Head gasket leak
Worn piston or rings

High compression may be caused by carbon deposits in the combustion
chamber.

ENGINE OIL AND FILTER REPLACEMENT

The engine oil replacement must be carried out with engine warm.
Remove the oil level and filter cap (fig. 9).
Loosen the oil drain plug (fig. 10) on the bottom left side of the engine,
then remove it carefully so as not to damage the mesh filter on it. Let the
oil drain completely.
Clean and blow out the mesh filter and then remount it and pour 2 litres of
oil into the filler cap.
Check oil level.
Start the engine, then stop it after an idle period of approx 1 minute.
If necessary, add some oil and check for leaks.
Every two oil changes, it is necessary to replace the filter cartridge .
Remove filter cartridge using appropriate tool 19.1.20520 (fig. 11).
Install new filter after lubrication of its gasket with engine oil.
The correct oil level is reached with 2.2 litres of new oil.
Recommended oil: AGIP SAE 15W/40 or AGIP SINT 2000.

SPARK PLUG

Disconnect spark plug cap and remove spark plug.
Check the spark plug and verify that the insulation isn’t cracked or
chipped.
Measure spark plug gap with feeler gauge; adjust gap by bending the
electrolyte carefully if necessary. Gap 0.6 ÷ 0.7 mm

Recommended spark plug
Champion A5YC
(alternatives: NGK DPR9EA9, DRP9EV9, Nippon Denso X27 EPRU-9,
X27 EPRZU-9

Make sure the seal washer is in good condition. Install the spark plug and
tighten by hand, then finish tightening with a spark plug socket to the
correct torque (12-15 Nm); reconnect spark plug cap.

3 - 4,1

MAINTENANCE 3 - 4

3 - 4,2

MAINTENANCE 3 - 5

THROTTLE CONTROLS

Check that the throttle grip turns freely from fully open to fully closed in all
steering positions (fig. 12).
Lubricate the throttle cable if found to be sticking.
Verify that the throttle grip has 2 to 5mm play; replace if found defective.
The end of the throttle cable goes in the hole in front of the throttle grip
(fig. 13).

CLUTCH

Measure clutch idle stroke at the lever’s extremity. Idle stroke 8 mm.
Use the adjuster nearest the lever for small adjustments.
More important adjustments can be carried out by moving of one single
tooth on its own knurled pin (fig. 14).

DRIVE CHAIN

Never inspect or lubricate the drive chain with the engine on.
Measure chain play midway between the driven and drive sprockets;
measure play by moving the chain up and down.
Max. play allowed 30 mm.

Chain slack adjustment

Loosen the two rear wheel eccentrics locking bolts (fig. 15).
Use the appropriate tool 19.1.20565 to rotate the eccentric to get the
correct slack on the chain. Make sure both eccentrics have turned the
same amount by checking the alignment notches (fig. 16).

Verify that the chain, drive and driven sprockets aren’t damaged or worn.
A drive chain with damaged rollers, loose bolts or missing retainer rings
must be replaced.
Never install a new chain on worn sprockets or a worn chain on new
sprockets.
The chain is equipped with small retainer rings; the retainer rings may be
damaged by steam cleaning, high pressure water and some solvents.
Clean chain with kerosene.
Dry chain and lubricate it with transmission oil SAE 80W 90.
Check for a worn rear fork chain guard.
Replace if the groove left by the chain is too deep.

3 - 5,1

MAINTENANCE 3 - 5

3 - 5,2

MAINTENANCE 3 - 6

Chain replacement

Remove pinion cover.
Remove pinion bolt and remove pinion (fig. 17).
Remove gearshift rod.
Loosen the bolt on the lower part of the engine and lift it out towards the
right (fig. 18).
Remove spacer bushing.
Remove chain guard cover.
Remove chain.
Install new chain and assemble components in reverse of disassembly.

REAR BRAKE PEDAL HEIGHT ADJUSTMENT

Adjust rear brake height by turning the adjusting screw (fig. 19).
Every time the pedal is adjusted, the play in the rear brake master cylinder
must be adjusted too.
Play in the master cylinder is adjusted by loosening the master cylinder’s
push rod lock nut, then rotate the rod in the desired position (fig. 20).

GEARSHIFT LEVER HEIGHT ADJUSTMENT

Loosen the gearshift rod.
Remove the joint and rotate it to the desired position (fig. 21).

FOOT PEDALS DAMPER BUSHINGS REPLACEMENT

Remove the socket head screw at the end of the pedal; remove the
bushing and aluminium coupler; replace bushings if worn (fig. 22).

Remove the pedal bolt.
Check bolt diameter, should be 16 mm (fig. 23).
Service limit: 0.05 mm.

Grease contact surfaces well before mounting the spindle (fig. 24).
Put a securing device at the end of the threaded spindle.
Mount spindle, bushings and aluminium coupler in reverse of disassembly.

TROUBLE SHOOTING

Oil level too low: External oil leak and/or worn piston rings and/or worn
valve guides.

Dirty oil: Oil and filter not replaced regularly and/or faulty head gasket
and/or worn piston rings.

3 - 6,1

MAINTENANCE 3 - 6

3 - 6,2

MAINTENANCE 3 - 7

ENGINE OIL LEVEL CHECK

Stand the motorcycle in a vertical position, on a flat surface.
Start up the engine and let it run at idle speed for about a minute.
Stop the engine and check the oil level through the transparent oil window
on the left side of the engine (fig. 29).
If necessary, remove the oil cap on the clutch guard (fig. 30) and add the
recommended oil to the engine until the maximum level is reached as
shown in the oil window.

3 - 7

MAINTENANCE 3 - 8

CLUTCH TRANSMISSION CYLINDER ON THE ENGINE
Removal

Place a clean receptacle under the clutch guard on the right of the engine.
Remove the clutch transmission cylinder from the clutch cover (fig. 40).

Be careful not to spill any hydraulic liquid on painted surfaces or
plastic or rubber parts. Always cover these parts when working on
the system.

Remove the clutch cylinder cover.
Place a tube on the bleeder screw, loosen it until an outlet of oil is seen.
Facilitate the outlet of oil by using the clutch lever.
Remove the hydraulic system tubing from the cylinder when no more oil
appears to be coming out.
Blow compressed air into the hydraulic liquid emission hole of the clutch
cylinder at short intervals, so that the piston is extracted.
Check that the piston and cylinder do not show signs of scratches or other
damage (fig. 41).
If there are signs of damage, replace the whole unit.
Push the piston grommet inside the cylinder to extract the piston, in case
of replacement.

Reassembly

The piston grommet must be replaced by another each time it is removed.
Reassemble the piston in the clutch transmission cylinder.
Mount the clutch transmission cylinder on the clutch guard, having
connected the hydraulic tubing to the cylinder itself.
Fill the liquid tank on the clutch pump with DOT 4 brake fluid and bleed the
hydraulic system.
Close the cover of the clutch cylinder, having fitted the rubber seal inside
the bowl.
If it should be necessary to work on the clutch with the engine mounted on
the frame, it is always necessary to release the return spring of the kick
starter before removing the clutch guard.
To do this, it is necessary to loosen and remove the return spring brake
bolt (fig. 42).

3 - 8,1

MAINTENANCE 3 - 8

3 - 8, 2

SECTION 4

INTENTIONALLY BLANK

ENGINE REMOVAL / INSTALLATION 5 - 1

5 - 1

Working procedures
Engine removal / installation

Section - Page

5 - 1
5 - 1

ENGINE REMOVAL - INSTALLATION 5 - 1

Working procedures

All operations must be carried out in a clean environment.
After disassembly of the parts, wash all components in kerosene or other
solvent (never use petrol) and blow dry with compressed air.
Carbon deposits are removed with a brush having brass bristles or a
scraper with chamfered corners.
All operations must be carried out in a precise order; mark all
components to be removed one at a time, or place them in separate
containers so as to mount them in the same position as prior to
disassembly.
Pay attention to the position of the component prior to removal so as to
mount it correctly upon reassembly.
The timing belt is never to come in contact with oil, petrol or grease and is
to be handled with clean hands only. Avoid bending or twisting the belt.
Gudgeon pin snap rings, gaskets, oil seals and rubber ring seals must be
substituted at every disassembly.
Lubricate all moving components prior to assembly.
Spring washers must always be installed with the convex side out.

When removing or installing the engine, always have the motorcycle
supported so that it will be steady.
Drain the motor oil.
Remove seat.
Remove petrol tank.
Drain cooling liquid by removing the drain plugs on the thermostat (fig. 1).
Disconnect the radiator thermostat wires.
Remove radiator.
Remove silencer.
Disconnect tachometer cable.
Disconnect clutch cable.
Loosen carburettor / intake manifold clamp.
Disconnect starter motor wires.
Disconnect oil breather hose from filter box.
Disconnect spark plug cap.
Remove pinion protection cover.
Remove pinion mounting nut (fig. 2).
Remove pinion.
Disconnect the oil pressure and neutral indicator wires.
Remove chain holder.
Remove ignition cover (fig. 3).

5 - 1,1

ENGINE REMOVAL - INSTALLATION 5 - 1

Remove the engine to frame top mounting bolts; remove the support
(figs. 4 - 5).
Remove the lower engine bolt (fig. 6).
Remove the other engine bolts.
Loosen (but don’t remove) the two fork bolts, to allow easier engine
removal.
Have another technician hold the motorcycle upon engine removal; the
geometry of the frame is such that it will offset the balance (loosely
translated to “the bike will fall over when engine is removed!”).
If working on cylinder head-cylinder-piston-connecting rod group, the
engine doesn’t need to be removed; in such a case, the following are the
instructions:

Remove seat and tank.
Drain cooling liquid and remove the radiator clamps; it’s not necessary to
remove the radiator.
Disconnect tachometer cable.
Disconnect clutch cable.
Remove the carburettor without disconnecting the throttle cable.
Disconnect the oil pressure and neutral indicator wires.
Remove ignition cover.
Disconnect starter motor wires.
Disconnect oil breather hose.
Remove rear brake fluid reservoir.
Remove brake hose to frame clamp.
Do not disconnect brake hose from reservoir.
Remove engine to frame top support.
Remove the 2 lower engine mounting bolts only.
Loosen rear damper plate to frame mounting nut / bolt (fig. 7).
Remove the bolt carefully and insert a pin in its place; this will keep the
damper in its original position and will avoid problems during installation
of the engine.
Lift the rear of the frame and with the help of another technician, separate
top frame-fork-front wheel group from engine-swing fork-rear wheel
group.
The cylinder head-cylinder-piston-connecting rod group may now be
worked on. After removing the head, the connecting rod may be checked
and replaced if necessary.

Engine installation

In either of the two cases described, assemble the components in
reverse order of disassembly.

5 - 1,2

ENGINE REMOVAL - INSTALLATION 5 - 1

5-1,3

GENERATOR - TIMING BELT -

GEARBOX SELECTOR 6

INDEX

6

Disassembly
Inspection
Reassembly
Valve timing
Torque wrench settings

Section - Page

6 - 1
6 - 1
6 - 2
6 - 2
6 - 3

GENERATOR - TIMING BELT -

GEARBOX SELECTOR 6 - 1

DISASSEMBLY

Remove generator cover mounting bolts together with stator and remove
cover (fig. 1).
Remove the timing belt cover; loosen idle roller nut and position the idle
roller in such a way as to permit the belt to come off the cam pulleys
(fig. 2).
Block generator rotor with special tool 19.1.20521, then loosen the
mounting bolt (fig. 3).
Protect the crankshaft end with the threaded pad (special tool

19.1.20513) and remove the generator rotor with extractor 19.1.20501
(figs. 4-5-6).
Pull off the two spring washers and the large guide washer from the
crankshaft end. Remove the timing belt (figs. 7-8).
Loosen the block side cover mounting bolts and remove cover (fig. 9).
Slide out the gearshift pedal shaft, together with selector drum assembly
(fig. 10).
Remove selector drum cam central bolt (fig. 11).
Remove crankshaft pinion using extractor 19.1.20514 (figs. 12-13).
Remove the electric starter’s freewheel / driven gear, complete with
bushing and caged needle bearing, from the balanced auxiliary shaft after
having removed its fastening bolt and spring washer. Lastly, remove the
triangular shaped washer (figs. 14-15-16).

INSPECTION

All removed components must be inspected carefully after having been
thoroughly cleaned with kerosene or other solvent and dried with
compressed air. All parts that show signs of damage or wear must be
replaced.
Be sure the pinion teeth aren’t excessively worn, freewheel group
functions properly (roller race must not show signs of pitting, grooving or
similar damage), as well as the selector drum control group.

6 - 1,1

GENERATOR - TIMING BELT -

GEARBOX SELECTOR 6 - 1

6 - 1,2

GENERATOR - TIMING BELT -

GEARBOX SELECTOR 6 - 1

6 - 1,3

GENERATOR - TIMING BELT -

GEARBOX SELECTOR 6 - 2

REASSEMBLY

Reassemble all components in reverse order of disassembly; pay close
attention to the following:
Replace the block’s left side cover gasket and the O-ring found behind
the final drive pinion.
Mount the pinion mounting bolt spring washer, of the freewheel starter
group and generator rotor, with the convex side facing out.
The two pinion mounting bolt spring washers, found behind the generator
rotor, and the timing belt’s large guide washer must be mounted as
shown in fig. 17.
The gap between the pick-up and rotor plate must be between 0.4 and

0.5 mm.
The drum selector control device may be adjusted if necessary. Select
either 2nd, 3rd or 4th gear and verify that (in the rest position) either
extremity of the lever is at the same distance to the drum’s adjacent drag
grain. Adjustment is made by turning the cam screw (on the lever) after
having loosened the lock nut.

VALVE TIMING
Put piston at TDC (indicated by aligning the reference mark on the

generator rotor with the fixed mark, as shown in fig. 18).
Place the camshafts with their reference marks facing as shown in fig. 19.
This operation must be carried out without actuating the valves (rotate it
clockwise or counter-clockwise as necessary).
Install the timing belt and take up the slack with the tensioner pulley.
After loosening the fastening nut, the calibrated spring will set the
tensioner pulley automatically. Be sure to let the belt align on the cam
pulleys by turning the crankshaft several times prior to fastening the nut.
After having fastened the nut, make sure the pulley reference marks align
with the fixed ones.
Toprque the nut to between 28 and 30 Nm.
Always replace the timing belt according to the scheduled maintenance
(every 12,000 km).
The timing belt is never to come in contact with oil, petrol or grease and is
to be handled with clean hands only. Avoid bending or twisting the belt.
The belt must be installed by hands only, that is, do not use screwdrivers
or other tools.

6 - 2,1

GENERATOR - TIMING BELT -

GEARBOX SELECTOR 6 - 2

6 - 2,2

GENERATOR - TIMING BELT -

GEARBOX SELECTOR 6 - 3

TORQUE WRENCH SETTINGS

6 - 3

Freewheel fastening bolt *
Generator rotor fastening bolt *
Chain sprocket fastening bolt **
Selector cam fastening bolt
Tensioner pulley fastening nut

* = Lubricate threads with oil
** = Use Loctite 270

40 Nm
40 Nm
40 Nm
40 Nm
40 Nm

CYLINDER HEAD VALVETRAIN

COMPONENTS 7

SUB INDEX

Diagram
Disassembly
Inspection
Reassembly
Torque wrench settings

Section - Page

7 - 1
7 - 2
7 - 3
7 - 4
7 - 4

7

CYLINDER HEAD VALVETRAIN COMPONENTS 7 - 1

7 - 1

CYLINDER HEAD VALVETRAIN

COMPONENTS 7 - 2

DISASSEMBLY

Pull off the water passage coupler mounted on the right side of the
head and remove the O-ring found under the coupler fitting (fig. 1).
Remove timing belt cover; loosen idle roller nut and position the idle
roller in such a way as to permit the belt to come off the two cam
pulleys (fig. 2).
Loosen the cylinder head nuts gradually and uniformly. This operation
must be executed in a diagonal crossed sequence.
Remove the head by carefully lifting it from its cylinder. If necessary
loosen the head by hitting it with a plastic mallet (fig. 3).
Block the two camshaft pulleys with special tool 19.1.00504, then
loosen the pulley bolts. Remove bolts with its washers and pull off the
pulleys (figs. 4-5).
Remove the cover plate of the rocker arm shaft retainer bushing (fig. 6).
Remove the cylinder head cover and remove the camshafts with their
oil seals (figs. 7-8)
Remove the valve lifter device (found on the left hand side of head,
near the exhaust valve) by extracting the retainer pin (fig. 9). The little
shaft together with the lifter may now be dismantled by hand.
Extract the retainer bushing and intake rocker arm shaft (use an 8mm
bolt with a 1.25 pitch) and remove the two rocker arms together with
spacer washers and spring. Repeat same procedure for the exhaust
side (fig. 10).
Compress each valve spring with special tool 19.1.20519, by pressing
on spring retainer with enough pressure to remove the collets. Next,
remove the spring retainer and the two outer/inner springs (figs. 11-12).
Slide out the valve from the guide; remove the oil seal (found on the
upper part of the guide and spring seat). Repeat same procedure for
the other valves (fig. 13).
Loosen nut and remove the belt tensioner pulley and spring (fig. 14).

7 - 2,1

CYLINDER HEAD VALVETRAIN

COMPONENTS 7 - 2

7 - 2,2

CYLINDER HEAD VALVETRAIN

COMPONENTS 7 - 2

7 - 2,3

CYLINDER HEAD VALVETRAIN

COMPONENTS 7 - 3

INSPECTION

After a thorough cleaning of all parts, place the components on the bench and
inspect them carefully. All those parts that show signs off wear and/or damage
must be replaced.

Head

Scrape the surface and remove traces of head gasket and remove all carbon
deposit in the combustion chamber. Be certain that all contact surfaces are in
good condition and that the combustion chamber shows no sign of cracks or
deep scratches (especially around the valve seats).
Check that the head surface is not warped by means of a straight gauge.
Max. planning error = 0.05 mm.
The surface may be planed to a max. of 0.2 mm if necessary.

Caution: do not machine the top surface of the head: this may cause the
shafts to lock.

Valves

Valve stems and seats must be in good condition.
Make sure that end of the stem doesn’t show signs of excessive wear.
In the event of valve seat wear, resurface by grinding.
Check that the valve stem is straight.
Max. straightness error allowed = 0.01 mm (fig. 15).
The face must be radial with respect to the stem (fig. 16).
Valve seat must be in good shape, with no sign of pitting, cracking or corrosion

Springs

After visual inspection of the springs and valves, measure the length of each
spring with a gauge (fig. 17).
Allowed values: Outer spring 38.7 ÷ 39.7 mm
Inner spring 37.6 ÷ 38.6 mm

Rocker arms

Make sure the runners (where the camshaft lobes hit against) are in good
condition and don’t have deep scratches, grooves or the like. Check for
excessive gap between rocker arm and shaft.
Max, gap = 0.08 mm

Camshaft

Make sure the camshaft lobes are in good condition, with no sign of damage or
Wear. Measure the height of each lobe. Check cam height on both sides; the
difference between both readings should not exceed 0.1 mm (fig. 18).
Check for excessive gap of the camshaft journals in their respective supports.
Max. radial clearance = 0.1 mm

7 - 3,1

CYLINDER HEAD VALVETRAIN

COMPONENTS 7 - 3

7 - 3,2

CYLINDER HEAD VALVETRAIN

COMPONENTS 7 - 4

REASSEMBLY

Assemble in reverse order of disassembly. Pay close attention to the following
points:
Every component must be installed in the same position before it was
removed. This is most important for rocker arms, valves, spring retainer and
collets.
Do not mix the two camshaft pulleys: the one marked with an “S” is for
exhaust: the one marked with an “A” is for intake.
Oil all moving components before mounting.
There is no gasket between the cam cover and the head; use Loctite 574.
Always use new oil seals for both valve guides and camshafts (for the latter,
use special tool 19.1.20502, for the former use special tool 19.1.20503). Oil
the lip seal before mounting.
Install the head gasket; make sure the correct side is facing up. All contact
surfaces must be clean and in good condition (fig. 19).
Between head and cylinder there are four rubber anti vibration devises that are
Installed after positioning the head gasket.
The head bolts are tightened in an even and progressive fashion, using a
crossed diagonal sequence and to the prescribed torque.

TORQUE WRENCH SETTINGS

Camshaft pulley mounting screws * 30 Nm
Head mounting bolts 32 ÷ 35 Nm
Cam cover mounting screws 7 ÷ 9 Nm

* Always oil threads and washers

7 - 4

INTENTIONALLY BLANK

CYLINDER - PISTON 8

SUB INDEX

Diagram
Disassembly
Inspection
Reassembly

Section - Page

8 - 1
8 - 2
8 - 2
8 - 2

8

CYLINDER - PISTON 8 - 1

8 - 1

CYLINDER - PISTON 8 - 2

DISASSEMBLY

Remove the head group, gasket and rubber anti-vibration devises, as
described in section 7.
Remove the water pump, found on the left of the cylinder (fig. 1).
Remove the thermostat’s housing on the front of the cylinder (fig. 2).
Lift the cylinder by hand. If necessary, use a plastic or rubber mallet to
break the seal (fig. 3).
After having removed the cylinder, cover the opening of the crankcase
with paper or clean cloth, then remove the gudgeon pin lockring (fig. 4)
and slide out pin using special tool 19.1.20530 as a punch.
If necessary use a mallet (remember to support the piston on the other
side) (fig. 5).
Remove the base gasket of the cylinder and the rubber O-ring, found
around the oil feed line (fig. 6).

INSPECTION
After a thorough cleaning of all parts, all components must go through a

careful visual inspection. Replace all parts that show sign of damage
and/or wear. Careful attention goes to cylinder wall, piston surfaces,
rings and gudgeon pin, with no signs of scoring, deep grooves,
shrinkage or any other damage.

Cylinder

Measure bore diameter (with a micrometer) at three different heights
and at 90° to one another (one measurement must be parallel to the
gudgeon pin) in order to see excessive ovalisation and taper.
If excessive wear is noted, both cylinder and piston must be replaced
(fig. 7).
Max. taper = 0.02 mm
Max. ovalisation = 0.01 mm

Piston

Piston diameter is measured at 90° to the gudgeon pin and again at 12
mm (350cc) and 7 mm (500cc) from the base of the skirt, using a
micrometer (fig. 8).
Min. clearance (service limit) = 0.1 mm

8 - 2,1

CYLINDER - PISTON 8 - 2

8 - 2,2

CYLINDER - PISTON 8 - 2

Piston rings

The rings are removed only when necessary.
These components are very fragile and must be removed and installed
very carefully.
To check for ring wear, take each ring and place it “squarely” inside the
lower part of the cylinder. Measure the end gap with a feeler gauge
(fig. 9).
Max. gap = 0.8 mm (350cc) 1 mm (500cc)
Make sure the rings have play (but not excessive) in their grooves (see
overhaul table on page 1 - 5 (PISTON/CYLINDER MATCHING CHART)

Gudgeon pin
Make sure the gudgeon pin doesn’t have an excessive radial clearance,

both around the connecting rod and piston.
Max. clearance piston / gudgeon pin = 0.06 mm
Max. clearance small end / gudgeon pin = 0.08 mm
For the most part, a satisfactory check can be carried out by sliding the
gudgeon pin (with little effort and no lubrication) into the piston and the
same gudgeon pin must not slide out by its own weight.

The water pump cannot be overhauled; if found damaged or worn, it
must be replaced as a unit.
Check that the thermostat isn’t damaged or scaled.
Verify that it starts to open at 75°C and that it is fully opened at 85°C.
Check condition of the thermostat’s O-ring.

REASSEMBLY
Assemble in reverse order of disassembly. Pay close attention to the

following points:
Piston rings are installed in a specific order and direction. The first two
rings are marked with the letters “TOP 2” and “TOP” for the first and
second ring respectively the scraper ring is installed with the chamfered
side up. (This exactly how it appears in the official manual, however the

consensus of opinion is that it should read “TOP and TOP 2”).

The piston must be installed in one direction only; the 350cc engine has
arrow marked on top of piston; for the 500cc engine, mark piston before
removal.
Always use new gaskets, O-rings and gudgeon pin lockrings.
Thoroughly oil the cylinder wall before fitting the piston; piston rings end
gap must be spaced throughout the circumference of the piston.
Do not forget the rubber O-ring that is placed around the oil feed line at
the base of the cylinder.
The cylinder is mounted to the base with two bushing guides around the
two studs.
The starter motor’s idler gear bolt is mounted with the milled part facing
up (fig. 11).

8 - 2,3

CYLINDER - PISTON 8 - 2

8 - 2,4

CLUTCH - PRIMARY DRIVE - OIL PUMP 9

SUB INDEX

Diagram
Disassembly
Inspection
Reassembly
Torque wrench setting

Section - Page

9 - 1
9 - 2
9 - 2
9 - 3
9 - 3

9

CLUTCH - PRIMARY DRIVE - OIL PUMP 9 - 1

9 - 1

CLUTCH - PRIMARY DRIVE - OIL PUMP 9 - 2

DISASSEMBLY

Drain the oil.
Loosen the kick starter bolt; remove cover plate mounting screws and
remove right side cover of the engine block.
Remove the seeger ring and the thrust bearing (fig. 1).
Block the drive gear of the primary drive with special tool 19.1.20515.
Remove clutch assembly mounting screw and washer (fig. 2).
Remove clutch hub together with clutch plate, pressure plate and driving
plate (fig. 3).
Remove the gearbox mainshaft, washer, clutch drum and spacer (fig. 4).
Remove the kick starter shaft (fig. 5).
Loosen the balance shaft fastening bolt (fig. 6)
Remove mounting screw and spring washer and slide out the drive gear
from the crankshaft of the primary drive. Remove special tool 19.1.20515
(figs. 7-8-9).
Remove the oil pump assembly complete with drive pinion (fig. 10).
Take off the pump’s rear cover and slide out the washer of the mainshaft.
Slide out both drive and driven gears from the balance shaft (fig. 11).
Remove the spacer washer near the right main bearing (fig. 9).

INSPECTION

After a thorough cleaning of all parts, inspect all components carefully. All
those parts that show sign of wear and/or damage must be replaced. All
gears must be in good condition, with no sign of wear, deep scratches or
pitting.

Clutch

The drum notches must be perfectly straight. If there is pitting or
undulations, replace drum.
If the flexible coupling springs seat is worn, replace drum.
The clutch hub slot must have its sides perfectly straight. If there is pitting
or undulation, replace hub.
The metal driven plate must be perfectly plane. Check it with a surface
plate. Max. planning error = 0.1 mm.
Make sure the plates don’t show signs of overheating.
Measure the drive plate gap with a gauge (fig. 12).
Min. gap = 2.7 mm.
If one or more plates show sign of wear or deformation, all plates must be
replaced; it is recommended to replace the springs too.

9 - 2,1

CLUTCH - PRIMARY DRIVE - OIL PUMP 9 - 2

9 - 2,2

CLUTCH - PRIMARY DRIVE - OIL PUMP 9 - 2

9 - 2,3

CLUTCH - PRIMARY DRIVE - OIL PUMP 9 - 3

REASSEMBLY

Assemble in reverse order of disassembly. Pay close attention to the
following points:
The crankshaft thrust ring is installed with the grooves facing out and it’s
notch in the cover’s seat.
When mounting the balance shaft, align it properly. To do this, align the
internal markings with the ones on the shaft together with the external
markings, as shown in (fig. 13).
N.B.: This engine is without balance shaft mark.
In this case the teeth inner surface present a triangular groove.
Operate in way that the groove is aligned with the balance shaft mark
(fig. 14).

Mount the clutch drum by inserting the oil pump pawl guide into its seat.
The clutch drive plates are installed with the arrow (imprinted on the
friction material) facing out.
Install the spring washers with the convex side facing out.
Oil all washers, gear mounting bolt threads and clutch hub, prior to
assembly.

TORQUE WRENCH SETTING

Primary drive gear mounting bolts * 40 Nm
Balance shaft gear mounting bolts * 40 Nm
Clutch hub mounting bolts * 40 Nm

* Always oil threads and washers

9 - 3

CRANKCASE - GEARBOX -

CRANKSHAFT COMPONENTS 10

SUB INDEX

Diagram
Disassembly
Inspection
Reassembly
Torque wrench settings

Section - Page

10 - 1
10 - 2
10 - 3
10 - 3
10 - 3

10

CRANKCASE - GEARBOX -

CRANKSHAFT COMPONENTS 10

10 - 1

CRANKCASE - GEARBOX -

CRANKSHAFT COMPONENTS 10

DISASSEMBLY

Make sure all necessary components are removed, then remove all bolts
that join the two halves of the cases. Open the crankcase and if
necessary use a plastic or rubber mallet to loosen it (carefully hit at the
joint of the cases and/or at the end of the gearbox shafts).

When separating the cases (fig. 1), check to see if a spacer washer (from
one of the shafts) has fallen out; reinstall if necessary.

Slide out the gear selector fork shaft and remove the forks (fig. 2).
Remove the selector drum, balance shaft and the two gear train shafts
(figs. 3-4-5).
Remove crankshaft with connecting rod (fig. 6). Loosen the nuts of the
connecting rod caps and remove the connecting rod from the shaft (fig. 7).

10- 2,1

CRANKCASE - GEARBOX -

CRANKSHAFT COMPONENTS 10

10 - 2,2

CRANKCASE - GEARBOX -

CRANKSHAFT COMPONENTS 10

INSPECTION

After a thorough cleaning of all parts, inspect all components carefully.
All those parts that show sign of wear and/or damage must be replaced.

Crankshaft

The crankshaft must be replaced if found damaged or worn.

Connecting rod

Install the half bearings and mount the connecting rod cap by tightening
the nuts to the proper torque setting (28 to 32 Nm). Measure the internal
diameter of the bearing with a micrometer.
Once the bearing and shaft journal diameter is known, it is possible to
calculate the radial clearance of the two components.
Clearance at mounting: 0.017 to 0.060 mm.
Max. clearance: 0.14 mm.
If it is necessary to replace the wrist pin, use special tool 19.1.20506 for
removal; to install use special tool 19.1.20505. Be careful to align the pin
lubrication hole with the one in the small end.

Connecting rod cap radial gap must be between 0.15 ÷ 0.25 mm.
It is recommended to replace connecting rod bolts at every overhaul.
Note the fitting of the connecting rod cap; mount the connecting rod in the

same direction it was taken out.

Gearbox

Make sure the selector forks aren’t bent and move freely on their shaft and
that there is a minimum clearance in each of the guide bolts inside the slot
of the selector drum.
Verify that the gap between the fork and gear train slot isn’t excessive.
Check carefully the condition of the gear train and be sure that the
mainshaft, transmission and fork shafts are perfectly straight.
Max. straightness error = 0.05 mm

10 – 3,1

CRANKCASE - GEARBOX -

CRANKSHAFT COMPONENTS 10

Crankcase

Accurately measure the internal diameter of each main journal with a
micrometer.
Diameter at mounting = 40.030 ÷ 40.046 mm.
Once the bearing and main journal internal diameter is known, it is
possible to calculate the gap of the two components.
Clearance at mounting = 0.030 ÷ 0.059 mm.
Max. clearance = 0.080 mm.

If it is necessary to replace the gearbox shaft rolling bearings, selector
drum and balance shaft, the cases must be heated uniformly (it is
recommended the use of an oven at 130°C, in order to avoid warpage).
Use extractor 19.1.20528 to remove the left case roller cage.

REASSEMBLY

Assemble in reverse order of disassembly. Pay close attention to the
following points:

Crankshaft, balance shaft and gears are all mounted in the left
crankcase.
Use Loctite 574 on the contact surface of the two cases.
The crankshaft thrust ring is installed in the right case (with the antifriction
surface side facing the shaft) and so is the selector drum spacer washer.
Hold these components in with a little grease.
Crankshaft axial clearance must be between 0.05 and 0.25 mm; if
necessary replace worn thrust rings with new ones.
To mount the oil seals, use a proper hollow punch; be careful not to
damage the lip seal by pits or grooves on the shaft (in such cases, it is
best to use a conical guide protection).
Oil the oil seal lips with engine oil.

TORQUE WRENCH SETTINGS

Connecting rod cap mounting nuts: 28 ÷ 32 Nm.
Lubricate threads.

10 – 3,2

FRAMES

INDEX

Working procedures
Front wheel
Front suspension - Steering
Rear suspension - Rear wheel
Brakes

Section

11
12
13
14
15

WORKING PROCEDURES 11

All operations must be carried out in a clean environment.
After disassembly of parts, wash all components in kerosene or other

solvent (never use petrol) and blow dry with compressed air.
All operations must be carried out in a precise order; mark all components

to be removed one at a time, or place them in separate containers so as to
mount them in the same position as prior to disassembly.

Pay attention to the position of the component prior to removal so as to
mount it correctly upon reassembly.

Lubricate all moving components prior to assembly.
Spring washers must always be installed with the convex side facing out.

11

FRONT WHEEL 12

SUB INDEX

Diagram
Disassembly
Reassembly
Technical data
Trouble shooting

Section - Page

12 - 1
12 - 2
12 - 3
12 - 3
12 - 4

12

FRONT WHEEL 12

12 - 1

FRONT WHEEL 12

DISASSEMBLY

Disconnect speedometer cable.
Loosen the spindle retainer bolts on the right leg.
Loosen and slide out wheel spindle with a pin (fig. 1)
Remove the wheel.

Don’t actuate the front brake lever once the wheel is removed, otherwise
it’ll be difficult to insert the brake disc between the brake pads on
reassembly.

Spindle straightness inspection

Place spindle on two V-shaped supports and measure eccentricity with a
comparator (fig. 2). Allowed limit: 0.20 mm.

Rim

Check rim centering on a centering bench. Spin wheel manually and
measure the centering error with a comparator (fig. 3).
Allowed limits:
Radial oscillation: 2.00 mm.
Axial oscillation: 2.00 mm.

Bearing inspection

Rotate each bearing’s inner ring with a finger. The bearings must turn
smoothly and without noise; make sure the outer part of the bearing is
permanently seated in the wheel hub (fig. 4).
Remove and replace bearings if the rings don’t turn freely, quietly or have
excessive play in the hub.

Brake disc inspection

Measure brake disc thickness (fig. 5).
Allowed limit: 4.5 mm

12 - 2,1

FRONT WHEEL 12

12- 2,2

FRONT WHEEL 12

Bearing disassembly

Remove the speedometer drive and drive gear dust cover ring (fig. 6).
Remove the wheel bearings and spacer bush from the wheel hub.
Do not reinstall the old bearings; once the bearings are removed, they
must be replaced with new ones.

Bearing reassembly

Fill bearing cavity with grease. Insert first the right bearing and mount the
spacer; insert the left bearing (fig. 7).
Place some grease on the inside of the dust cover and mount it (fig. 8).
Install the speedometer drive gear ring in the wheel hub aligning the tabs
with the slot. Grease the speedometer drive and mount it in the wheel hub
aligning the tabs with the slot (fig. 9).

REASSEMBLY

Place calliper on brake disc, being careful not to damage the pads. Clean
wheel spindle and mount it. There are no spindle thrust or spacer
washers.
Tighten the spindle to the recommended torque, then connect cable to the
speedometer drive.

12 - 2,3

FRONT WHEEL 12

12 - 2,4

FRONT WHEEL 12

REASSEMBLY

Place calliper on brake disc, being careful not to damage the pads. Clean
wheel spindle and mount it. There are no spindle thrust or spacer
washers.
Tighten the spindle to the recommended torque, then connect cable to the
speedometer drive.

TECHNICAL DATA

Standard values
Wheel rim centering error ± 0.5 mm
Fork spring free length 420 mm
Front forks oil capacity 310 cc for each side

12 - 3

FRONT WHEEL 12

TROUBLE SHOOTING
Stiff steering:

Steering bearing adjusting ring nut too tight.
Faulty steering sleeve bearings.
Tyre pressure too low.

Tends to steer to one side and has poor handling:

Bent front forks.
Bent front wheel spindle.
Wheel not mounted properly.
Different quantity of oil in the two fork legs.

Front wheel oscillation:

Bent rim.
Worn front wheel bearings.
Damaged tyre.
Incorrectly torqued wheel spindle.

Suspension too soft:

Insufficient fork oil.
Fork oil too thin.
Weakened fork springs.

Suspension too hard:

Too much fork oil.
Fork oil too dense.
Damaged leg or stanchion.

Noisy front suspension:

Fork stanchion sticky.
Insufficient oil in forks.
Loose front fork bolts.

Poor braking performance:

Missing or insufficient brake fluid.
Worn brake pads.
Worn brake disc.

The use of a proper support is necessary when working on the front wheel
or forks.

12 - 4

SUSPENSION - STEERING 13

Diagram
Removal
Inspection
Reassembly

Section - Page

13 - 1
13 - 2
13 - 3
13 - 3

13

SUSPENSION - STEERING 13

13 - 1

SUSPENSION - STEERING 13

REMOVAL

Remove the fairing’s two side mounting screws; remove the side view
mirrors mounting screws and remove the mirrors.
Disconnect the front turning signal wires and remove the fairing.
Remove the front wheel.
Loosen the bolt’s safety screws of the semi-handlebars (fig. 1).
Loosen the handlebar’s fastening bolts (fig. 2).
Remove the brake calliper mounting bolts.
Loosen the mudguard mounting bolts and remove mudguard.
Loosen the stanchion mounting bolts at the steering head.
Loosen the upper fork steering yoke mounting bolt and remove the
steering yoke.
Remove the steering bearings adjusting ring nut (fig. 3) and pull out the
semi-handlebars.
Pull out the lower steering yoke with both stanchions and legs.
Remove the outer steering sleeve rings; check that the bearings ring races
are in good shape; if worn replace both rings and bearings.
If the motorcycle has been in an accident, check for cracks around the
steering head.

Steering sleeve lower bearing replacement

Remove bearing with the appropriate tool (fig. 4).

Steering sleeve assembly

Grease the bearings.
Install the sleeve in the steering head and install the upper bearing.
Tighten the bearings adjusting ring nut to the recommended torque.
Turn the steering sleeve from one side to the other several times, then
tighten the ring nut.

Stanchion leg disassembly

Place stanchion in a vice and remove top fork plug.
Pull off the spring. Drain the fork oil by pumping several times (fig. 5).
Secure the leg in a padded vice.
Remove the socket bolt. If this operation becomes difficult, temporarily
remount the spring and fork plug.

13- 2,1

SUSPENSION - STEERING 13

13 - 2,2

SUSPENSION - STEERING 13

Pull out the stanchion and damper piston.
Be careful not to confuse the left leg’s piston and other components with
those of the right because they’re not interchangeable.
Left fork (fig. 6).
Right fork (fig. 7).

Stanchion inspection

Place the stanchion on V-shaped supports and check for straightness
error (fig. 8). The real centering error corresponds to half the comparator
reading. Allowed limit: 0.2 mm

Fork spring inspection

Measure the spring’s free length (fig. 9).
Free length: 420 ± 2.5 mm
Min. length: 415 mm

Verify that the stanchion and leg don’t show signs of abrasions, scratches
and excessive or abnormal wear.
Replace any worn or damaged components.

Oil seal replacement

Remove the oil seal retainer ring and remove the oil seal.
Avoid damage to the leg’s internal and external surfaces.
The oil seals may be replaced without pulling the stanchions from the fork
yokes.
Mount the oil seals then retainer ring.

REASSEMBLY

Clean all components with a solvent and dry thoroughly prior to
remounting.
Mount the piston ring, release spring, spring seat, valve and piston collar
(fig. 10).
Insert the piston group in the stanchion and mount the snap ring.
Insert stanchion in leg. Secure leg in a padded vice; place some locking
material to the socket head bolt threads and tighten to the correct torque.

13 – 2,3

SUSPENSION - STEERING 13

13 – 3,4

SUSPENSION - STEERING - 13

Fill each stanchion with the correct amount of damping oil.
Inspect the fork plug’s O-ring and replace if necessary.
Install the fork tube spring with the narrow spiral facing up.
Right fork component reassembly (figs. 11-12).
Left fork component reassembly (figs. 13-14).

Install the spacer spring and tighten to the correct torque.
Install the stanchion in the steering column and yoke by rotating it by
hand.
Make sure the end of each stanchion is aligned with the end of the yoke.
Tighten the yoke and steering column bolts of one side.
Tighten the bolts of the other side.
Install the front mudguard and brake calliper.
Mount the front tyre.

13 – 3,5

INTENTIONALLY BLANK

REAR SUSPENSION AND WHEEL 14

SUB INDEX

Diagram
Technical data
Troubleshooting
Wheel
Suspension
Final Drive

Section - Page

14 - 1
14 - 2
14 - 2
14 - 2
14 - 3
14 - 4

14

REAR SUSPENSION AND WHEEL 14

14 - 1

REAR SUSPENSION AND WHEEL 14

TECHNICAL DATA

Wear limit
Centering error 2.0 mm
Rear wheel spindle runout 0.20 mm

TROUBLESHOOTING
Motorcycle oscillations and vibrations

Deformed rim.
Loose wheel bearings.
Defective tyre.
Wrong tyre pressure.
Chain adjustment eccentrics not aligned equally.

Suspension too soft

Weakened fork springs.
Insufficient fork oil.

Suspension too hard

Bent damper rod.
Fork pivot bolt bearings or suspension rods worn or damaged.

WHEEL
Removal

Lift the wheel and place on support; loosen the wheel spindle nut (fig. 1).
Pull the spindle out only half way.
Let the brake calliper bracket and wheel spacer hang down.
Pull out the wheel spindle fully. Remove chain from sprocket and pull out
the wheel.
Don’t actuate the brake pedal once the wheel is removed, otherwise it’ll be
difficult to insert the brake disc between the brake pads on reassembly.

Wheel spindle inspection

Place spindle on two V-shaped supports and measure eccentricity with a
comparator (fig. 2). Allowed limit 0.20 mm

Wheel eccentricity

Place the wheel on a support and measure the eccentricity on the outer
wheel edge. Spin the wheel manually and measure the centering error
with a comparator (fig. 3).
Allowed limits: Radial oscillation; 2.0 mm. Axial oscillation; 2.0 mm.
Place wheel on a support and check bearing play rotating it by hand.
Replace bearings if they are noisy or have excessive play.

14 - 2,1

REAR SUSPENSION AND WHEEL 14

14 - 2,2

REAR SUSPENSION AND WHEEL 14

Chain sprocket inspection

Check sprocket teeth; replace if worn or damaged.
Check both the chain and driven sprocket.
Sprocket in good shape (fig. 4A).
Replace sprocket (fig. 4B).
Max. allowable wear (fig. 5).

NOTE

The sprocket retainer hub (flange) is mounted on the rim.
The flexible coupling screws are the same ones that hold the chain
sprocket to the flange.
Loosen the bolts that act as pivot bolts to the flexible couplings to remove
the sprocket from the flange (fig. 6).
Replace the rubber flexible couplings if damaged or worn.
The flexible couplings are made up by two components; one inner metal
ring and one outer rubber ring (fig. 7).
If the wheel bearings need to be replaced, remove the bearings and
spacer; once removed, the bearings must always be replaced with new
ones. Use a hydraulic press and the correct tool to mount the bearings
(fig. 8).

Sprocket flange bearings replacement

Remove snap ring (fig. 9).
Remove coupler.
Remove bearings (fig. 10).

Sprocket flange bearings reassembly

Install bearings (fig. 11).
Install wheel spindle coupling.
Install snap ring.
Remember to always grease the bearings.

14 - 2,3

REAR SUSPENSION AND WHEEL 14

14 - 2,4

REAR SUSPENSION AND WHEEL 14

Wheel reassembly

Place wheel in swing fork and place the spacers (fig. 12).
Place chain on sprocket.
Insert the spindle in the chain tension adjuster eccentric and push it into
the hub. Mount the spindle nut from the other side. Adjust chain tension
and tighten the wheel spindle to the correct torque.
The chain tension adjuster eccentrics must be pulled out from the inside of
the swing fork.

SUSPENSION
Removal

Remove the suspension mounting bolt.
Remove the top suspension mounting bolt (fig. 14).
Remove the bolt between the damper arm and fork and the bolt between
the damper arm and damper pivot joint (fig. 15). Remove damper.
Inspect the damper and make sure there are no signs of dents, oil leaks or
other damage; make sure the damper rod isn’t bent.
Replace damper if necessary.

Reassembly

Place some grease on the upper and lower damper mounting bolts prior to
installation.
Mount damper and tighten the upper and lower bolts to the correct torque.

Damper pivot joint and swing fork

Remove rear wheel. Remove silencer. Remove lower damper pivot
bolt. Remove the two fork side pivot bolts (fig. 16). Remove fork.
Remove the fork damper arm by removing its mounting bolt.

Inspection

Check that the swing fork isn’t cracked or otherwise damaged.
Make sure the uni-balls don’t have excessive play.
Make sure the fork chain guard isn’t worn or damaged.

Fork pivot bolt uni-ball replacement

Remove the two spacers (fig. 17).
Remove the two dust covers.
Remove the snap ring found on the inside (fig. 18).

14 - 3,1

REAR SUSPENSION AND WHEEL 14

14 - 3,2

REAR SUSPENSION AND WHEEL 14

Remove the uni-ball with the aid of a hydraulic press using special tool

19.1.20566 (fig. 19).
Make sure the uni-ball isn’t worn or damaged; replace if necessary
(fig. 20).
Mount the fork pivot bolt bushing with the aid of a press and the proper
mounting tool (fig. 21).
Mount the snap ring and dust cover.

Bushings and pivot bolt inspection

Make sure that the bearings and bushings aren’t worn or damaged;
replace if necessary.
Remove the dust covers then the bushings with the appropriate tool
(fig. 22).

Bushings reassembly

Use a hydraulic press and a pin to mount the new bushings in the damper/
fork pivot (fig. 23). Grease and then mount the dust cover.

Pivot bolts inspection

Measure the bolts with a micrometer (fig. 24).
Wear limit dia: 15.95 mm
Replace both bolts and rods if worn.
Measure the pivot bolt with a micrometer (fig. 25).
Wear limit dia: 17.92 mm
Replace both bolt and bushings if worn.
Check for surface markings produced by the rods caged rollers.

Swing fork reassembly

Mount fork onto frame.
Be careful when installing the spacers alignment pin between the two
aluminium plates (fig. 26). The pin keeps the spacer from rotating
between the plates thereby avoiding interference with the damper.
Install the right and left pivot bolts. Tighten the bolts to the correct torque.
Install the fork/damper pivot bolts and tighten to the correct torque.
Install the silencer.
Mount the wheel.

14 - 3,3