clutch YAMAHA TTR90 2003 User Guide

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

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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)

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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)

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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

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ENGOIL PUMP
OIL PUMP
Extent of removal:1 Oil pump removal2 Oil strainer removal
3 Oil pump disassembly
Extent of removal Order Part name Q’ty Remarks
OIL PUMP REMOVAL AND DIS-
ASSEMBLY
Preparation for removal Clutch housing and clutch carrier Refer to “CLUTCH” section.
Shift shaft Refer to “SHIFT SHAFT” section.
1 Rotary filter 1
2 Oil pump assembly 1
3 Gasket 1
4 Oil pump drive gear 1
5 Oil strainer 1
6 Circlip 1
7 Oil pump driven gear 1
8 Spring washer 1
9 Circlip 1
10 Washer 1
1
2
3

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ENGCDI MAGNETO AND STARTER CLUTCH
CDI MAGNETO AND STARTER CLUTCH
Extent of removal:1 Pickup coil/stator removal2 Rotor removal
3 Starter clutch/wheel gear removal
Extent of removal Order Part name Q’ty Remarks
CDI MAGNETO AND STATOR
REMOVAL
Preparation for removal Fuel tank
Crankcase cover (left) Refer to “CLUTCH” section.
1 CDI magneto coupler 1
2 Pickup coil/stator assembly 1
3 Rotor nut 1
Use special tool.
Refer to “REMOVAL POINTS”. 4 Rotor 1
5 Woodruff key 1
6 Shaft 1
7 Idler gear 1
8 Starter clutch/wheel gear 1/1
1
2
3

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ENGCDI MAGNETO AND STARTER CLUTCH
REMOVAL POINTS
Rotor
1. Remove:
Rotor nut 1
Washer 2
NOTE:
Loosen the rotor nut while holding the rotor
with sheave holder 3.
Do not allow the sheave holder to touch the
projection on the rotor.
Sheave holder:
YS-1880-A/90890-01701
2. Remove:
Rotor 1
Woodruff key
NOTE:
Use the flywheel puller 2.
Center the flywheel puller over the rotor.
Make sure after installing the holding bolts
that the clearance between the flywheel
puller and the rotor is the same everywhere.
If necessary, one holding bolt may be turned
out slightly to adjust the flywheel puller’s
position.
CAUTION:
Cover the crankshaft end with the box
wrench for protection.
Flywheel puller:
YU-33270-B/90890-01362

4 - 41
ENG
INSPECTION
Starter clutch
1. Inspect:
Starter idle gear teeth a
Starter drive gear teeth b
Starter wheel gear teeth c
Burrs/chips/roughness/wear →
Replace.
2. Check:
Starter clutch operation
Push the dowel pins to the arrow direc-
tion.
Unsmooth operation → Replace.
Checking steps:
Hold the starter clutch.
When turning the starter wheel gear clock-
wise Å, the starter clutch and the starter
wheel gear should be engaged.
If not, the starter clutch is faulty. Replace
it.
When turning the starter wheel gear coun-
terclockwise ı, it should turn freely.
If not, the starter clutch is faulty. Replace
it.
ı
Å
ASSEMBLY AND INSTALLATION
Starter clutch
1. Install:
Starter clutch 1
1T R..14 Nm (1.4 m · kg, 10 ft · lb)
2. Unloosen the starter clutch assembly by
using the center punch.
CDI MAGNETO AND STARTER CLUTCH