2003 YAMAHA TTR90 clutch

4 - 27
ENG

CLUTCH
CLUTCH
CRANKCASE COVER (LEFT AND RIGHT)
Extent of removal:
1
Crankcase cover (left) removal
2
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
ENG

CLUTCH
CLUTCH
Extent of removal:
1
Friction plate and clutch plate removal
2
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.
Refer to “REMOVAL POINTS”. 9 Lock washer 1
10 Clutch boss 1
11 Washer 1
12 Clutch housing 1
1
23

4 - 29
ENG

CLUTCH
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

4 - 30
ENG

CLUTCH
REMOVAL POINTS
Clutch boss
1. Remove:

Clutch boss nut
1


Lock washer
2


Clutch boss
NOTE:

Straighten the lock washer tab and use the
clutch holding tool
3
to hold the clutch boss.
Å
For USA and CDN
ı
Except for USA and CDN
Clutch holding tool:
YM-91042/90890-04086
Å
ı

Primary clutch
1. Remove:

Primary clutch nut
1
NOTE:
Loosen the nut while holding the magneto
rotor with the sheave holder 2.
INSPECTION
EC484500
Friction plate
1. Measure:
Friction 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:
Clutch 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:
Clutch spring free length a
Out of specification → Replace springs
as a set.
Push rod
1. Measure:
Push 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:
Primary 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:
Clutch 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)

4 - 32
ENGCLUTCH
ASSEMBLY AND INSTALLATION
Primary clutch
1. Install:
Washer 1
Nut (primary clutch) 2
NOTE:
Tighten the nut while holding the magneto
rotor with the sheave holder 3.
Clutch
1. Install:
Lock washer 1
Nut (clutch boss) 2
NOTE:
Use the clutch holding tool 3 to hold the clutch
boss.
ÅFor USA and CDN
ıExcept for USA and CDN
2. Bend:
Lock 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)
Åı
Clutch release adjustment
1. Adjust:
Clutch release
Adjustment steps:
Loosen the locknut 1.
Turn in the adjuster 2 until it is lightly
seated.
Turn out by 1/8 turn.
Tighten the locknut.
T R..
Locknut:
8 Nm (0.8 m • kg, 5.8 ft • lb)

4 - 33
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

4 - 34
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