wheel YAMAHA YZ426F 2000 Owner's Manual

ENG
4 - 60
KICK AXLE AND SHIFT SHAFT
KICK AXLE AND SHIFT SHAFT
KICK AXLE AND SHIFT SHAFT
Extent of removal:1 Kick axle removal2 Kick axle disassembly
3 Shift shaft4 Segment removal
Extent of removal Order Part name Q’ty Remarks
KICK AXLE AND SHIFT SHAFT
REMOVAL
Preparation for removal Shift pedalRefer to “ENGINE REMOVAL” section.
Oil pumpRefer to “OIL PUMP” section.
1 Kick idle gear 1
2 Kick axle assembly 1 Refer to “REMOVAL POINTS”.
3 Spring guide 1
4 Torsion spring 1
5 Ratchet wheel 1
6 Kick gear 1
7 Kick axle 1
8 Plain washer 1
9 Shift shaft 1
10Collar
1
3
2
1
4
1

4 - 62
ENG

KICK AXLE AND SHIFT SHAFT
REMOVAL POINTS
EC4B3101
Kick axle assembly
1. Remove:
l
Kick axle assembly
1

NOTE:

Unhook the torsion spring
2
from the hole
a
in the crankcase.
EC4C3101
Shift guide and shift lever assembly
1. Remove:
l
Bolt (shift guide)
l
Shift guide
1

l
Shift lever assembly
2

NOTE:

The shift lever assembly is disassembled at
the same time as the shift guide.
EC4N3100
Segment
1. Remove:
l
Bolt (segment)
1

l
Segment
2

NOTE:

Turn the segment counterclockwise until it
stops and loosen the bolt.
EC4C4000
INSPECTION
EC4B4100
Kick axle and ratchet wheel
1. Check:
l
Ratchet wheel smooth movement
Unsmooth movement
®
Replace.
2. Inspect:
l
Kick axle
1

Wear/damage
®
Replace.
Kick gear, kick idle gear and ratchet wheel
1. Inspect:
l
Kick gear
1

l
Kick idle gear
2

l
Ratchet wheel
3

l
Gear teeth
a

Wear/damage
®
Replace.

4 - 65
ENGKICK AXLE AND SHIFT SHAFT
EC4B5302
Kick axle assembly
1. Install:
lKick gear 1
lRatchet wheel 2
NOTE:
Align the punched mark a on the ratchet
wheel with the punched mark b on the kick
axle.
2. Install:
lTorsion spring 1
To kick axle 2.
NOTE:
Make sure the stopper a of the torsion spring
fits into the hole b on the kick axle.
3. Install:
lSpring guide 1
NOTE:
Slide the spring guide into the kick axle, make
sure the groove a in the spring guide fits on
the stopper of the torsion spring.
4. Install:
lKick axle assembly 1
lPlain washer 2
NOTE:
lApply the engine oil on the kick axle.
lSlide the kick axle assembly into the crank-
case, make sure the kick axle stopper a fit
into their home position b.
5. Hook:
lTorsion spring 1
NOTE:
Turn the torsion spring clockwise and hook
into the proper hole a in the crankcase.

4 - 68
ENGCDI MAGNETO
EC4L3000
REMOVAL POINTS
EC4L3101
Rotor
1. Remove:
lNut (rotor) 1
lPlain washer
Use the rotor holding tool 2.
2. Remove:
lRotor 1
Use the flywheel puller 2.
NOTE:
When installing the flywheel puller, turn it
counterclockwise.
EC4L4000
INSPECTION
EC4L4101
CDI magneto
1. Inspect:
lRotor inner surface a
lStator outer surface b
Damage ® Inspect the crankshaft
runout and crankshaft bearing.
If necessary, replace CDI magneto and/
or stator.
EC4L4200
Woodruff key
1. Inspect:
lWoodruff key 1
Damage ® Replace.
Rotor holding tool:
YU-01235/90890-01235
Flywheel puller:
YM-01189/90890-01189
EC4L5000
ASSEMBLY AND INSTALLATION
EC4L5181
CDI magneto
1. Install:
lStator 1
lBolt (stator) 2
T R..10 Nm (1.0 m · kg, 7.2 ft · lb)

4 - 88
ENGTRANSMISSION, SHIFT CAM, SHIFT FORK
2. Install:
l2nd wheel gear (27T) 1
l4th wheel gear (24T) 2
l3rd wheel gear (23T) 3
l5th wheel gear (20T) 4
l1st wheel gear (24T) 5
lO-ring 6
To drive axle 7.
NOTE:
lApply the molybdenum disulfide oil on the
1st, 2nd and 3rd wheel gears inner circum-
ference and on the end surface.
lApply the molybdenum disulfide oil on the
4th and 5th wheel gears inner circumfer-
ence.
lApply the lithium soap base grease on the O-
ring.
3. Install:
lPlain washer 1
lCirclip 2
NOTE:
lBe sure the circlip sharp-edged corner a is
positioned opposite side to the plain washer
and gear b.
lBe sure the circlip end c is positioned at
axle spline groove d.
New
4. Install:
lSpacer 1
NOTE:
lApply the lithium soap base grease on the oil
seal lip.
lWhen installing the spacer into the crank-
case, pay careful attention to the crankcase
oil seal lip.

4 - 89
ENGTRANSMISSION, SHIFT CAM, SHIFT FORK
5. Install:
lShift fork 1 (L) 1
lShift fork 2 (C) 2
lShift fork 3 (R) 3
lShift cam 4
To main axle and drive axle.
NOTE:
lApply the molybdenum disulfide oil on the
shift fork grooves.
lMesh the shift fork #1 (L) with the 4th wheel
gear 5 and #3 (R) with the 5th wheel gear
7 on the drive axle.
lMesh the shift fork #2 (C) with the 3rd pinion
gear 6 on the main axle.
6. Install:
lTransmission assembly 1
To crankcase (left) 2.
NOTE:
Apply the engine oil on the bearings and guide
bars.
7. Check:
lShifter operation
lTransmission operation
Unsmooth operation ® Repair.

5 - 1
CHAS

EC500000
CHASSIS
EC590000
FRONT WHEEL AND REAR WHEEL
EC598000
FRONT WHEEL
FRONT WHEEL AND REAR WHEEL
Extent of removal:
1
Front wheel removal
2
Wheel bearing removal
3
Break disc removal
Extent of removal Order Part name Q’ty Remarks
Preparation for removal
FRONT WHEEL REMOVAL
Hold the machine by placing the
suitable stand under the engine.
1 Hose cover 1
2 Bolt (brake hose holder) 2 Only loosening.
3 Bolt (axle holder) 4 Only loosening.
4 Nut (front wheel axle) 1
5 Front wheel axle 1
6 Front wheel 1
7 Collar 2
8 Oil seal 2
9 Bearing 2 Refer to “REMOVAL POINTS”.
10Brake disk
1
WARNING
Support the machine securely so there is nodanger of it falling over.
2
31
3

5

5 - 2
CHAS

EC598100
REAR WHEEL
Extent of removal:
1
Rear wheel removal
2
Wheel bearing removal
3
Break disc removal
Extent of removal Order Part name Q’ty Remarks
Preparation for removal
REAR WHEEL REMOVAL
Hold the machine by placing the
suitable stand under the engine.
1 Nut (rear wheel axle) 1
2 Rear wheel axle 1
3 Chain puller 2
4 Rear wheel 1 Refer to “REMOVAL POINTS”.
5 Collar 2
6 Driven sprocket 1
7 Oil seal 2
8 Circlip 1
9 Bearing 2 Refer to “REMOVAL POINTS”.
10Brake disk
1
WARNING
Support the machine securely so there is nodanger of it falling over.
2
31
3

FRONT WHEEL AND REAR WHEEL

5 - 3
CHAS

FRONT WHEEL AND REAR WHEEL
EC593000
REMOVAL POINTS
EC523101
Rear wheel
1. Remove:
l
Wheel
1

NOTE:

Push the wheel forward and remove the drive
chain
2
.
EC513201
Wheel bearing (if necessary)
1. Remove:
l
Bearing
1

NOTE:

Remove the bearing using a general bearing
puller
2
.
EC594000
INSPECTION
EC514100
Wheel
1. Measure:
l
Wheel runout
Out of limit
®
Repair/replace.
2. Inspect:
l
Bearing
Rotate inner race with a finger.
Rough spot/seizure
®
Replace.
NOTE:

Replace the bearings, oil seal and wheel collar
as a set.
Wheel runout limit:
Radial
1
: 2.0 mm (0.08 in)
Lateral
2
: 2.0 mm (0.08 in)

5 - 4
CHAS

FRONT WHEEL AND REAR WHEEL
EC514200
Wheel axle
1. Measure:
l
Wheel axle bends
Out of specification
®
Replace.
Use the dial gauge
1
.
NOTE:

The bending value is shown by one half of the
dial gauge reading.
WARNING

Do not attempt to straighten a bent axle.
Wheel axle bending limit:
0.5 mm (0.020 in)
EC514302
Brake disc
1. Measure:
l
Brake disc deflection
Use the dial gauge
1
.
Out of specification
®
Inspect wheel
runout.
If wheel runout is in good condition,
replace the brake disc.
2. Measure:
l
Brake disc thickness
a

Out of limit
®
Replace.
Disc deflection limit:
0.15 mm (0.006 in)
Disc wear limit:
Standard

Front
3.0 mm (0.12 in) 2.5 mm (0.10 in)
Rear
4.0 mm (0.16 in) 3.5 mm (0.14 in)