2002 YAMAHA TTR90 clutch

4 - 27
ENGCLUTCH
CLUTCH
CRANKCASE COVER (LEFT AND RIGHT)
Extent of removal:1 Crankcase cover (left) removal2 Crankcase cover (right) removal
Extent of removal Order Part name Q’ty Remarks
CRANKCASE COVER (LEFT
AND RIGHT) REMOVAL
Preparation for removal Drain the engine oil. Refer to “ENGINE OIL REPLACEMENT”
section in the CHAPTER 3.
1 Shift pedal 1
2 Drive sprocket cover 1
3 Crankcase cover (left) 1
4 Gasket 1
5 Dowel pin 2
6 Clutch adjusting screw 1
7 Kick crank 1
8 Crankcase cover (right) 1
9 Gasket 1
10 Dowel pin 2
1
2

4 - 28
ENGCLUTCH
CLUTCH
Extent of removal:1 Friction plate and clutch plate removal2 Clutch housing removal
3 Primary clutch removal
Extent of removal Order Part name Q’ty Remarks
CLUTCH REMOVAL
1 Bolt/clutch spring 4/4
2 Pressure plate 1
3 Washer 1
4 Push rod #1 1
5 Friction plate 5
6 Clutch plate 4
7 Push rod #2 1
8 Clutch boss nut 1 Use special tool.
9 Lock washer 1
Refer to “REMOVAL POINTS”.
10 Clutch boss 1
11 Washer 1
12 Clutch housing 1
1
23

4 - 29
ENGCLUTCH
Extent of removal Order Part name Q’ty Remarks
13 Spacer 1
14 Spacer 1
15 Primary clutch nut 1 Use special tool.
Refer to “REMOVAL POINTS”.
16 Washer 1
17 Spacer 1
18 Primary clutch housing 1
19 Primary clutch boss 1
20 Clutch carrier 1
21 One-way clutch assembly 1
22 Washer 1
3
2

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ENGCLUTCH
REMOVAL POINTS
Clutch boss
1. Remove:
lClutch boss nut 1
lLock washer 2
lClutch boss
NOTE:
Straighten the lock washer tab and use the
clutch holding tool 3 to hold the clutch boss.
For USA and CDN
õExcept for USA and CDN
Clutch holding tool:
YM-91042/90890-04086
õ
Primary clutch
1. Remove:
lPrimary clutch nut 1
NOTE:
Loosen the nut while holding the magnet rotor
with the sheave holder 2.
INSPECTION
EC484500
Friction plate
1. Measure:
lFriction plate thickness
Out of specification ® Replace friction
plate as a set.
Measure at all four points.
Sheave holder:
YS-1880-A/90890-01701
Friction plate thickness
Standard Limit
2.7 ~ 2.9 mm
(0.106 ~ 0.114 in)2.6 mm
(0.102 in)

4 - 31
ENGCLUTCH
EC484600
Clutch plate
1. Measure:
lClutch plate warpage
Out of specification ® Replace clutch
plate as a set.
Use a surface plate 1 and thickness
gauge 2.
EC484400
Clutch spring
1. Measure:
lClutch spring free length a
Out of specification ® Replace springs
as a set.
Push rod
1. Measure:
lPush rod #2 bend
Out of specification ® Replace.
Warp limit:
0.2 mm (0.008 in)
Clutch spring free length
Standard Limit
26.2 mm
(1.03 in)24.2 mm
(0.95 in)
Bending limit:
0.5 mm (0.02 in)
Primary clutch
1. Measure:
lPrimary clutch housing inside diameter
Out of specification ® Replace.
Primary clutch housing inside
diameter:
105 mm (4.13 in)
: 106 mm (4.17 in)
2. Measure:
lClutch shoe groove depth a
Out of specification ® Replace.
Clutch shoe groove depth:
1.0 ~ 1.3 mm (0.039 ~ 0.051 in)
: 0.1 mm (0.004 in)

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ENGCLUTCH
ASSEMBLY AND INSTALLATION
Primary clutch
1. Install:
lWasher 1
lNut (primary clutch) 2
NOTE:
Tighten the nut while holding the magneto
rotor with the sheave holder 3.
Clutch
1. Install:
lLock washer 1
lNut (clutch boss) 2
NOTE:
Use the clutch holding tool 3 to hold the clutch
boss.
For USA and CDN
õExcept for USA and CDN
2. Bend:
lLock washer tab
Sheave holder:
YS-1880-A/90890-01701
Clutch holding tool:
YM-91042/90890-04086
T R..50 Nm (5.0 m · kg, 36 ft · lb)
New
T R..70 Nm (7.0 m · kg, 50 ft · lb)

Clutch release adjustment
1. Adjust:
lClutch release
Adjustment steps:
lLoosen the locknut 1.
lTurn in the adjuster 2 until it is lightly
seated.
lTurn out by 1/8 turn.
lTighten the locknut.
T R..
Locknut:
8 Nm (0.8 m • kg, 5.8 ft • lb)

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ENGKICK AXLE
KICK AXLE
Extent of removal:1 Kick axle removal2 Kick axle disassembly
Extent of removal Order Part name Q’ty Remarks
KICK AXLE REMOVAL AND
DISASSEMBLY
Preparation for removal Crankcase cover (right) Refer to “CLUTCH” section.
1 Kick axle assembly 1
2 Circlip 2
3 Spring cover 1
4 Torsion spring 1
5 Spring guide 1
6 Circlip 1
7 Ratchet wheel 1
8 Clip 1
9 Circlip 1
10 Washer/wave washer 1/1
11 Kick gear 1
12Kick axle
1
1
2

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ENGSHIFT SHAFT
SHIFT SHAFT
Extent of removal:1 Shift shaft removal
Extent of removal Order Part name Q’ty Remarks
SHIFT SHAFT REMOVAL
Preparation for removal Clutch housing and clutch carrier Refer to “CLUTCH” section.
1 Shift fork guide bar 1
2 Shift arm 3 1
3 Plate washer 1
4 Compression spring 1
5 Shift guide 1
6 Ball holder 1
7 Guide 1
8 Dowel pin 1
9 Plate washer 1
10 Thrust bearing 1
11 Circlip 1
12 Shift lever assembly 1
13 Shift shaft 1
1