clutch YAMAHA YZ85 2003 User Guide

2 - 16
SPEC
EC240000
CABLE ROUTING DIAGRAM
1Hose guide
2Brake hose
3Throttle cable
4Fuel tank breather hose
5Engine stop switch lead
6CDI magneto lead
7Clamp
8Carburetor breather hose
9Carburetor overflow hose
0Transmission oil breather hose
ARadiator breather hose
BClutch cable
CSpark plug leadDCable guide
EBrake hose holder
ÈPass the fuel tank breather hose between the
handlebar and tension bar, then insert its end
into the hole of the steering stem.
ÉFasten the ground lead together with the ignition
coil.
ÊClamp the brake hose with the brake hose
holder.
ËFit the brake hose into the guides of the protec-
tor.
CABLE ROUTING DIAGRAM

2 - 17
SPEC
1Sub-wire harness
2CDI unit
3Ignition coil
4Clutch cable
5Cable guide
6Transmission oil breather hose
7CDI unit band
8Clamp
9Brake hose
0Brake hose holder
AHose guide
BReservoir hose
CReservoir tank
DBrake master cylinderÈPass the transmission oil breather hose through
the hose guide.
ÉClamp the sub-wire harness at the tape on it
within the arrow mark.
ÊPass the sub-wire harness on the left of the CDI
unit.
ËPass the reservoir hose between the brake hose
and swingarm bracket.
ÌPass the reservoir hose through the hose guides.
ÍInstall the brake hose so that its pipe portion
directs as shown and lightly touches the projec-
tion on the brake master cylinder.
CABLE ROUTING DIAGRAM

2 - 18
SPEC
1Throttle cable
2Clutch cable
3Clamp
4Engine stop switch lead
5Brake hose
6Hose guideÈFasten the engine stop switch lead to the han-
dlebar with the plastic band.
ÉPass the brake hose in front of the number plate.
ÊCross the clutch cable and throttle cable over
the number plate boss.
CABLE ROUTING DIAGRAM

3 - 1
INSP
ADJ
MAINTENANCE INTERVALS
EC300000
REGULAR INSPECTION AND ADJUSTMENTS
MAINTENANCE INTERVALS
The following schedule is intended as a general guide to maintenance and lubrication. Bear in mind
that such factors as weather, terrain, geographical location, and individual usage will alter the
required maintenance and lubrication intervals. If you are a doubt as to what intervals to follow in
maintaining and lubricating your machine, consult your Yamaha dealer.
ItemAfter
break-inEvery
raceEvery
third
raceEvery
fifth
raceAs re-
quiredRemarks
PISTON
Inspect and clean
Replace







Inspect crack
Inspect carbon deposits
and eliminate them
PISTON RING
Inspect
Replace





Check ring end gap
PISTON PIN, SMALL END BEARING
Inspect
Replace




CYLINDER HEAD
Inspect and clean
Retighten







Inspect carbon deposits
and eliminate them
Check gasket
CYLINDER
Inspect and clean
Replace




Inspect score marks
Inspect wear
CLUTCH
Inspect and adjust
Replace





Inspect housing, friction
plate, clutch plate and
spring
TRANSMISSION
Replace oil
Inspect
Replace bearing






Yamalube 4 (10W-30) or
SAE 10W-30 SE motor oil
SHIFT FORK, SHIFT CAM, GUIDE BAR
Inspect

Inspect wear
ROTOR NUT
Retighten




KICK SHAFT
Inspect idle gear
Replace




EXHAUST PIPE, SILENCER
Inspect
Clean





CRANK
Inspect and clean



CARBURETOR
Inspect, adjust and clean



SPARK PLUG
Inspect and clean
Replace





DRIVE CHAIN
Lubricate, slack, alignment
Replace




Chain slack: 35 ~ 45 mm
(1.4 ~ 1.8 in)

3 - 4
INSP
ADJ
PRE-OPERATION INSPECTION AND MAINTENANCE
EC320000
PRE-OPERATION INSPECTION AND MAINTENANCE
Before riding for break-in operation, practice or a race, make sure the machine is in good operating
condition.
Before using this machine, check the following points.
GENERAL INSPECTION AND MAINTENANCE
Item Routine Page
CoolantCheck that coolant is filled up to the radiator cap.
Check the cooling system for leakage.P.3-5 ~ 9
FuelCheck that a fresh mixture of oil and gasoline is filled in the fuel
tank. Check the fuel line for leakage.P.1-12
Transmission oilCheck that the oil level is correct. Check the crankcase for leak-
age.P.3-12 ~ 13
Gear shifter and clutchCheck that gears can be shifted correctly in order and that the
clutch operates smoothly.P.3-9
Throttle grip/HousingCheck that the throttle grip operation and free play are correctly
adjusted. Lubricate the throttle grip and housing, if necessary.P.3-10
Brakes Check the play of front brake and effect of front and rear brake. P.3-16 ~ 21
Drive chainCheck drive chain slack and alignment. Check that the drive
chain is lubricated properly.P.3-22 ~ 24
WheelsCheck for excessive wear and tire pressure. Check for loose
spokes and have no excessive play.P.3-31 ~ 32
SteeringCheck that the handlebar can be turned smoothly and have no
excessive play.P.3-32 ~ 34
Front forks and rear shock
absorberCheck that they operate smoothly and there is no oil leakage. P.3-24 ~ 30
Cables (wires)Check that the clutch and throttle cables move smoothly. Check
that they are not caught when the handlebars are turned or
when the front forks travel up and down.—
Exhaust pipe and silencerCheck that the exhaust pipe is tightly mounted and has no
cracks.P.4-2
Rear wheel sprocket Check that the rear wheel sprocket tightening bolt is not loose. P.3-22
Lubrication Check for smooth operation. Lubricate if necessary. P.3-35
Bolts and nuts Check the chassis and engine for loose bolts and nuts. P.1-16
Lead connectorsCheck that the CDI magneto, CDI unit, and ignition coil are con-
nected tightly.P.1-6
SettingsIs the machine set suitably for the condition of the racing course
and weather or by taking into account the results of test runs
before racing? Are inspection and maintenance completely
done?P.7-1 ~ 19

3 - 9
INSP
ADJ
CLUTCH ADJUSTMENT
CAUTION:

Do not apply pressure more than speci-
fied pressure.

Radiator should be filled fully.
4. Inspect:

Pressure
Impossible to maintain the specified pres-
sure for 10 seconds → Repair.

Radiator 1

Radiator hose joint 2
Coolant leakage → Repair or replace.

Radiator hose 3
Swelling → Replace.
5PA30080
CLUTCH ADJUSTMENT
1. Check:

Clutch lever free play a
Out of specification → Adjust.
Clutch lever free play
a:
10 ~ 15 mm (0.39 ~ 0.59 in)
5PA30090
2. Adjust:

Clutch lever free play
NOTE:

Make minute adjustment on the lever side.

After adjustment, check proper operation of
clutch lever. Clutch lever free play adjustment steps:

Loosen the locknut 1.

Turn the adjuster 2 until free play a is
within the specified limits.

Tighten the locknut.
5PA30100

3 - 35
INSP
ADJ
LUBRICATION
LUBRICATION
To ensure smooth operation of all compo-
nents, lubricate your machine during setup,
after break-in, and after every race.
1All control cable
2Clutch lever pivot
3Shift pedal pivot
4Footrest pivot
5Throttle-to-handlebar contact
6Drive chain
7Tube guide cable winding portion
8Throttle cable end
9Clutch cable endÈUse Yamaha cable lube or equivalent on these
areas.
ÉUse SAE 10W-30 motor oil or suitable chain
lubricants.
ÊLubricate the following areas with high quality,
lightweight lithium-soap base grease.
CAUTION:
Wipe off any excess grease, and avoid get-
ting grease on the brake discs.
AAA
AAB
CC
5PA307705PA307805PA30790
5PA308005PA308105PA30820
5PA308005PA30840

4 - 26
ENGCLUTCH AND PRIMARY DRIVEN GEAR
EC490000
CLUTCH AND PRIMARY DRIVEN GEAR
EC498000
CLUTCH PLATE AND FRICTION PLATE
5PA40720
Extent of removal:
1 Clutch plate and friction plate removal
Extent of removal Order Part name Q’ty Remarks
CLUTCH PLATE AND FRIC-
TION PLATE REMOVAL
Preparation for removal Drain the transmission oil. Refer to “TRANSMISSION OIL
REPLACEMENT” section in the CHAP-
TER 3.
Clutch cable Disconnect at engine side.
1 Clutch cover 1
2 Bolt (clutch spring) 5
3 Clutch spring 5
4 Pressure plate 1
5 Friction plate 7
6 Clutch plate 6
1

4 - 27
ENG
EC498200
PRIMARY DRIVEN GEAR, PUSH ROD AND PUSH LEVER SHAFT
5PAR0006
Extent of removal:
1 Push rod and push lever shaft removal
2 Primary driven gear removal
Extent of removal Order Part name Q’ty Remarks
PRIMARY DRIVEN GEAR,
PUSH ROD AND PUSH LEVER
SHAFT REMOVAL
1 Push rod 1 1
2Ball 1
3 Push rod 2 1
4 Nut (clutch boss) 1
Use special tool.
Refer to “REMOVAL POINTS”. 5 Conical washer 1
6 Clutch boss 1
7 Washer 1
8 Primary driven gear 1
9Spacer 1
10 Washer 1
11 Push lever shaft 1
2
1
1
2
CLUTCH AND PRIMARY DRIVEN GEAR

4 - 28
ENG
REMOVAL POINTS
Clutch boss
1. Remove:

Nut (clutch boss) 1

Conical washer 2

Clutch boss 3
NOTE:
Use the clutch holding tool 4 to hold the clutch
boss.
ÈFor USA and CDN
ÉExcept for USA and CDN
Clutch holding tool:
YM-91042/90890-04086
5PA40740
ÈÉ
5PA40750
EC494000
INSPECTION
EC484100
Clutch housing and boss
1. Inspect:

Clutch housing 1
Cracks/wear/damage → Replace.

Clutch boss 2
Scoring/wear/damage → Replace.
5PA40760
EC484201
Primary driven gear
1. Check:

Circumferential play
Free play exists → Replace.

Gear teeth
a
Wear/damage → Replace.
5PA40770
Clutch spring
1. Measure:

Clutch spring free length
a
Out of limit → Replace springs as a set.
Clutch spring free length:
34.0 mm (1.34 in)
: 32.0 mm (1.26 in)
5PA40780
CLUTCH AND PRIMARY DRIVEN GEAR