clutch YAMAHA TTR90 2001 User Guide

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

4 - 30
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
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
ENG

CLUTCH
EC484600
Clutch plate
1. Measure:
l
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:
l
Clutch spring free length
a

Out of specification
®
Replace springs
as a set.
Push rod
1. Measure:
l
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:
l
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:
l
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
ENG

CLUTCH
ASSEMBLY AND INSTALLATION
Primary clutch
1. Install:
l
Washer
1

l
Nut (primary clutch)
2

NOTE:

Tighten the nut while holding the magneto
rotor with the sheave holder
3
.
Clutch
1. Install:
l
Lock washer
1

l
Nut (clutch boss)
2

NOTE:

Use the clutch holding tool
3
to hold the clutch
boss.

For USA and CDN
õ
Except for USA and CDN
2. Bend:
l
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..60 Nm (6.0 m · kg, 43 ft · lb)


Clutch release adjustment
1. Adjust:
l
Clutch release
Adjustment steps:
l
Loosen the locknut
1
.
l
Turn in the adjuster
2
until it is lightly
seated.
l
Turn out by 1/8 turn.
l
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

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ENG

SHIFT 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

4 - 36
ENG

OIL PUMP
OIL PUMP
Extent of removal:
1
Oil pump removal
2
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

4 - 39
ENGCDI MAGNETO
CDI MAGNETO
Extent of removal:1 Pickup coil/stator assembly removal2 Rotor 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
1
2

4 - 41
ENG

CRANKCASE AND CRANKSHAFT
CRANKCASE AND CRANKSHAFT
Extent of removal Order Part name Q’ty Remarks
CRANKCASE SEPARATION
AND CRANKSHAFT REMOVAL
Preparation for removal Seat, fuel tank and rear fender
Exhaust pipe
Air filter case
Carburetor Refer to “CARBURETOR” section.
Drain the engine oil Refer to “ENGINE OIL REPLACEMENT”
section in the CHAPTER 3.
Engine guard and drive sprocket
Engine assembly From the chassis.
Cylinder head Refer to “CYLINDER HEAD” section.
Cylinder and piston Refer to “CYLINDER AND PISTON” sec-
tion.
Clutch housing and clutch carrier Refer to “CLUTCH” section.
Kick axle assembly Refer to “KICK AXLE” section.