clutch YAMAHA YZ85 2002 Owner's Manual

4 - 29
ENG
Friction plate
1. Measure:
lFriction plate thickness
Out of limit ® Replace friction plate as a
set.
Measure at all four points.
EC484600
Clutch plate
1. Measure:
lClutch plate warpage
Out of limit ® Replace clutch plate as a
set.
Use a surface plate 1 and thickness
gauge 2.
Friction plate thickness:
2.9 ~ 3.1 mm
(0.114 ~ 0.122 in)
: 2.7 mm (0.106 in)
Warp limit:
0.1 mm (0.004 in)
5PA40790
5PA40800
Push lever shaft
1. Inspect:
lPush lever shaft 1
Wear/damage ® Replace.
5PA40810
Push rod
1. Inspect:
lPush rod 1 1
lBall 2
lPush rod 2 3
Wear/damage/bend ® Replace.
5PA40820
CLUTCH AND PRIMARY DRIVEN GEAR

4 - 30
ENG
ASSEMBLY AND INSTALLATION
Push lever shaft
1. Install:
lPush lever shaft 1
NOTE:
lApply the lithium soap base grease on the oil
seal lip and push lever shaft end.
lApply the transmission oil on the push lever
shaft.5PA40830
Clutch
1. Install:
lWasher [thickness 2 mm (0.08 in)] 1
lSpacer 2
lPrimary driven gear 3
NOTE:
Apply the transmission oil on the washer,
spacer and primary driven gear inner circum-
ference.
2. Install:
lWasher [thickness 4 mm (0.16 in)] 1
lClutch boss 2
5PA40840
5PA40850
3. Install:
lConical washer 1
NOTE:
Install the conical washer to the main axle 2
as shown in the illustration.
5PA40860
CLUTCH AND PRIMARY DRIVEN GEAR

4 - 31
ENG
4. Install:
lNut (clutch boss) 1
NOTE:
Use the clutch holding tool 2 to hold the clutch
boss.
ÈFor USA and CDN
ÉExcept for USA and CDN
Clutch holding tool:
YM-91042/90890-040865PA40870
T R..70 Nm (7.0 m · kg, 50 ft · lb)
È€É
5PA40880
5. Install:
lFriction plate 1 1
lClutch plate 2
lFriction plate 2 3
NOTE:
lInstall the clutch plates and friction plates
alternately on the clutch boss, starting with a
friction plate and ending with a friction plate.
lUse the friction plates 1 for the first and final
while paying attention to the difference in
surface pattern.
lApply the transmission oil on the friction
plates and clutch plates.
5PA40890
5PA40900
6. Install:
lPush rod 2 1
lBall 2
lPush rod 1 3
NOTE:
Apply the transmission oil on the push rod 1, 2
and ball.
5PA40910
CLUTCH AND PRIMARY DRIVEN GEAR

4 - 32
ENG
7. Install:
lPressure plate 1
NOTE:
Align the punch mark a on the pressure plate
with the punch mark b on the clutch boss.
5PA40920
8. Install:
lClutch spring 1
lBolt (clutch spring) 2
NOTE:
Tighten the bolts (clutch spring) in stage, using
a crisscross pattern.
5PA40930
T R..6 Nm (0.6 m · kg, 4.3 ft · lb)
9. Install:
lDowel pin 1
lGasket (clutch cover) 2
5PA40940
10. Install:
lClutch cover 1
lBolt (clutch cover) 2
NOTE:
Tighten the bolts in stage, using a crisscross
pattern.
5PA40950
T R..10 Nm (1.0 m · kg, 7.2 ft · lb)
CLUTCH AND PRIMARY DRIVEN GEAR

4 - 33
ENGKICK SHAFT, SHIFT SHAFT AND PRIMARY DRIVE GEAR
KICK SHAFT, SHIFT SHAFT AND PRIMARY DRIVE GEAR
PRIMARY DRIVE GEAR
5PA40960
Extent of removal:
1 Primary drive gear removal
Extent of removal Order Part name Q’ty Remarks
PRIMARY DRIVE GEAR
REMOVAL
Drain the transmission oil. Refer to “TRANSMISSION OIL
REPLACEMENT” section in the CHAP-
TER 3.
Brake pedal
Radiator hose 2 Disconnect at water pump side.
1 Kickstarter crank 1
2 Right crankcase cover 1
3 Nut (primary drive gear) 1 Only loosening.
Refer to “REMOVAL POINTS”.
4 Primary driven gear 1 Refer to “CLUTCH AND PRIMARY
DRIVEN GEAR” section.
5 Primary drive gear 1
1

4 - 39
ENG
Primary drive gear
1. Install:
lStraight key 1
5PA41160
2. Install:
lPrimary drive gear 1
lConical washer 2
lNut (primary drive gear) 3
NOTE:
lTemporarily tighten the nut at this point.
lInstall the conical washer to the crankshaft
4 as shown in the illustration.
5PA41170
3. Install:
lPrimary driven gear
Refer to “CLUTCH AND PRIMARY
DRIVEN GEAR” section.
4. Tighten:
lNut (primary drive gear) 1
NOTE:
Place an aluminum plate a between the teeth
of the primary drive gear 2 and driven gear
3.
5PA41180
T R..79 Nm (7.9 m · kg, 57 ft · lb)
5. Install:
lDowel pin 1
lGasket (right crankcase cover) 2
5PA41190
KICK SHAFT, SHIFT SHAFT AND PRIMARY DRIVE GEAR

4 - 49
ENG
EC4M0000
ENGINE REMOVAL
5PA41490
Extent of removal Order Part name Q’ty Remarks
ENGINE REMOVAL
Preparation for removal Hold the machine by placing the
suitable stand under the frame.
WARNING
Support the machine securely so there is no
danger of it falling over.
Drain the coolant. Refer to “COOLANT REPLACEMENT”
section in the CHAPTER 3.
Seat and fuel tank Refer to “SEAT, FUEL TANK AND SIDE
COVERS” section.
Carburetor Refer to “CARBURETOR AND REED
VALVE” section.
Exhaust pipe and silencer Refer to “EXHAUST PIPE AND
SILENCER” section.
Clutch cable Disconnect at engine side.
Radiator hose 1 Disconnect at cylinder head side.
Radiator hose 2 Disconnect at water pump side.
Spark plug cap
Disconnect the CDI magneto
lead.
ENGINE REMOVAL

5 - 41
CHAS
EC5B0000
HANDLEBAR
5PA51290
Extent of removal:
1 Handlebar removal
Extent of removal Order Part name Q’ty Remarks
Preparation for removalHANDLEBAR REMOVAL
Number plate Remove the clamp portion only.
1 Clutch cable 1 Disconnect at the lever side.
2 Clutch lever holder 1
3 Engine stop switch 1
4 Brake master cylinder 1 Refer to “REMOVAL POINTS”.
5 Throttle cable cap 1
6 Grip cap (lower) 1
7 Grip cap (upper) 1
8 Throttle cable 1 Disconnect at the throttle side.
9 Right grip 1 Refer to “REMOVAL POINTS”.
10 Tube guide 1
11 Collar 1
12 Left grip 1 Refer to “REMOVAL POINTS”.
13 Handlebar upper holder 2
14 Handlebar 1
1
HANDLEBAR

5 - 45
CHAS
7. Install:
lEngine stop switch 1
lClutch lever holder 2
lBolts (clutch lever holder) 3
lClamp 4
NOTE:
The engine stop switch and clutch lever holder
should be installed according to the dimen-
sions shown.
5PA51420
T R..4 Nm (0.4 m · kg, 2.9 ft · lb)
5PA51430
8. Install:
lClutch cable 1
NOTE:
Apply the lithium soap base grease on the
clutch cable end.
5PA51440
9. Adjust:
lClutch lever free play
Refer to “CLUTCH ADJUSTMENT” section
in the CHAPTER 3.
10. Clamp the clamp portion a of the number
plate to the handlebar.
11. Insert the end of the fuel tank breather
hose 1 into the hole of the steering stem.
5PA51450
HANDLEBAR