engine oil YAMAHA YZ426F 2001 Owner's Guide

4 - 49
ENGCLUTCH
EC4A5000
ASSEMBLY AND INSTALLATION
Push lever
1. Install:
lPush lever 1
lBolt (push lever)
NOTE:
lApply the lithium soap base grease on the oil
seal lip.
lApply the engine oil on the push lever.
lFit the seat plate 2 in the groove a of the
push lever 1 and tighten the bolt (seat
plate).
2
1
a
T R..10 Nm (1.0 m · kg, 7.2 ft · lb)
Clutch
1. Install:
lSeat plate 1
lClutch damper spring 2
lFriction plate 1 [d = ø128 mm (5.04 in)]
3
lClutch plate 4
To clutch boss 5.
NOTE:
lInstall the clutch damper spring with the
“OUT SIDE” mark a facing out.
lInstall the clutch plate with its sharp-edged
corner side b facing the engine.
4 3 2 1 5
a
b
3
5
1
243
1
2
4
2. Install:
lPrimary driven gear 1
lThrust washer 2
lClutch boss 3
NOTE:
Apply the engine oil on the primary driven gear
inner circumference.

4 - 50
ENGCLUTCH
3. 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
Clutch holding tool:
YM-91042/90890-04086
New
T R..75 Nm (7.5 m · kg, 54 ft · lb)

õ
4. Bend the lock washer 1 tab.
5. Install:
lFriction plate 2 [d = ø119 mm (4.69 in)]
1
lClutch plate 2
NOTE:
lInstall the clutch plates and friction plates 2
alternately on the clutch boss, starting with a
friction plate and ending with a friction plate.
lApply the engine oil on the friction plates and
clutch plates.
6. Install:
lBearing 1
lPlain washer 2
lCirclip 3
To push rod 1 4.
NOTE:
Apply the engine oil on the bearing and plain
washer.
New

4 - 51
ENGCLUTCH
7. Install:
lPush rod 2 1
lBall 2
lPush rod 1 3
NOTE:
Apply the engine oil on the push rod 1, 2 and
ball.
8. Install:
lPressure plate 1
9. Install:
lClutch spring
lBolt (clutch spring)
NOTE:
Tighten the bolts in stage, using a crisscross
pattern.
T R..8 Nm (0.8 m · kg, 5.8 ft · lb)
10. Install:
lGasket (clutch cover) 1
lDowel pin 2
New
11. Install:
lClutch cover 1
lBolt (clutch cover)
NOTE:
Tighten the bolts in stage, using a crisscross
pattern.
T R..10 Nm (1.0 m · kg, 7.2 ft · lb)

4 - 52
ENG
OIL FILTER, WATER PUMP AND CRANKCASE COVER
(RIGHT)
OIL FILTER, WATER PUMP AND CRANKCASE COVER (RIGHT)
OIL FILTER, WATER PUMP AND CRANKCASE COVER (RIGHT)
Extent of removal:1 Oil filter removal2 Water pump removal
3 Crankcase cover (right) removal
Extent of removal Order Part name Q’ty Remarks
OIL FILTER, WATER PUMP
AND CRANKCASE COVER
(RIGHT) REMOVAL
Preparation for removal Drain the engine oil. Refer to “ENGINE OIL REPLACEMENT”
section in the CHAPTER 3.
Drain the coolant. Refer to “COOLANT REPLACEMENT”
section in the CHAPTER 3.
Exhaust pipe Refer to “EXHAUST PIPE AND
SILENCER” section.
Brake pedal Refer to “ENGINE REMOVAL” section.
Clutch cover Refer to “CLUTCH” section.
1 Oil filter cover 1
2 Oil filter 1
3 Coolant pipe 2 1
4 Water pump housing 1
5 Pin 2
6 Oil delivery pipe 1
1
2
3

4 - 56
ENG
OIL FILTER, WATER PUMP AND CRANKCASE COVER
(RIGHT)
EC4G5220
Impeller shaft
1. Install:
lImpeller shaft 1
lPlain washer 2
lImpeller 3
NOTE:
lTake care so that the oil seal lip is not dam-
aged or the spring does not slip off its posi-
tion.
lWhen installing the impeller shaft, apply the
engine oil on the oil seal lip, bearing and
impeller shaft. And install the shaft while
turning it.
lHold the impeller shaft on its width across
the flats a with spanners, etc. and remove
the impeller.
T R..14 Nm (1.4 m · kg, 10 ft · lb)
Crankcase cover (right)
1. Install:
lDowel pin 1
lO-ring 2
lCollar 3
lGasket 4 New
2. Install:
lCrankcase cover (right) 1
lBolt
NOTE:
lApply the engine oil on the impeller shaft
end.
lWhen installing the crankcase cover onto the
crankcase, be sure that the impeller shaft
end 2 aligns with the balancer end slot 3.
lTighten the bolts in stage, using a crisscross
pattern.
T R..10 Nm (1.0 m · kg, 7.2 ft · lb)

4 - 64
ENG

OIL PUMP
INSPECTION
Oil pump
1. Inspect:
l
Oil pump drive gear
l
Oil pump driven gear
l
Rotor housing
l
Oil pump cover
Cracks/wear/damage
®
Replace.
2. Measure:
l
Tip clearance
a

Between the inner rotor
1
and the
outer rotor
2
.
l
Tip clearance
b

Between the outer rotor
2
and the rotor
housing
3
.
Out of specification
®
Replace the oil
pump.
Tip clearance
a
:
0.12 mm or less
(0.0047 in or less)
: 0.20 mm (0.006 in)
Tip clearance
b
:
0.09 ~ 0.17 mm (0.0035 ~ 0.0067 in)
: 0.24 mm (0.009 in)
Side clearance
c
:
0.03 ~ 0.10 mm (0.0012 ~ 0.0039 in)
: 0.17 mm (0.007 in)
3. Check:
l
Unsmooth
®
Repeat steps #1 and #2
or replace the defective parts.
ASSEMBLY AND INSTALLATION
Oil pump
1. Install:
l
Oil pump drive shaft
1
lWasher 2
lPin 3
lInner rotor 1 4
NOTE:
lApply the engine oil on the oil pump drive
shaft and inner rotor 1.
lFit the pin into the groove in the inner rotor 1.

4 - 65
ENGOIL PUMP
2. Install:
lOuter rotor 1 1
NOTE:
Apply the engine oil on the outer rotor 1.
3. Install:
lOil pump cover 1
lScrew (oil pump cover) 2
lPin 3
lInner rotor 2 4
lCirclip 5
NOTE:
lApply the lithium soap base grease on the oil
pump drive shaft end and inner rotor 2.
lFit the pin into the groove in the inner rotor 2.
4. Install:
lOuter rotor 2 1
lDowel pin 2
lOil pump assembly 3
lBolt (oil pump assembly)
[L = 30 mm (1.18 in)] 4
lBolt (oil pump assembly)
[L = 25 mm (0.98 in)] 5
NOTE:
Apply the lithium soap base grease on the
outer rotor 2.
T R..4 Nm (0.4 m · kg, 2.9 ft · lb)
New
T R..10 Nm (1.0 m · kg, 7.2 ft · lb)
T R..10 Nm (1.0 m · kg, 7.2 ft · lb)
5. Install:
lOil pump drive gear 1
lPlate washer 2
lCirclip 3
NOTE:
Apply the engine oil on the oil pump drive gear
inner circumference.
New

4 - 70
ENGKICK AXLE AND SHIFT SHAFT
EC4B5111
Stopper lever
1. Install:
lTorsion spring 1
lStopper lever 2
lBolt (stopper lever) 3
NOTE:
Align the stopper lever roller with the slot on
segment.
T R..10 Nm (1.0 m · kg, 7.2 ft · lb)
Shift guide and shift lever assembly
1. Install:
lSpring 1
lPawl pin 2
lPawl 3
To shift lever 4.
NOTE:
Apply the engine oil on the springs, pawl pins
and pawls.
2. Install:
lShift lever assembly 1
To shift guide 2.2
1
3. Install:
lShift lever assembly 1
lShift guide 2
NOTE:
lThe shift lever assembly is installed at the
same time as the shift guide.
lApply the engine oil on the bolt (segment)
shaft.

4 - 71
ENGKICK AXLE AND SHIFT SHAFT
4. Install:
lBolt (shift guide) 1
T R..10 Nm (1.0 m · kg, 7.2 ft · lb)
EC4C5301
Shift shaft
1. Install:
lRoller 1
lCollar 2
lTorsion spring 3
lShift shaft 4
NOTE:
Apply the engine oil on the roller and shift
shaft.
Kick axle assembly
1. Install:
lKick gear 1
lPlain washer 2
lCirclip 3
lRatchet wheel 4
lSpring 5
lPlain washer 6
lCirclip 7
To kick axle 8.
NOTE:
lApply the molybdenum disulfide oil on the
kick gear inner circumference.
lAlign the punch mark a on the ratchet wheel
with the punch mark b on the kick axle.
New
New
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.

4 - 72
ENGKICK AXLE AND SHIFT SHAFT
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 3.
5. Hook:
lTorsion spring 1
NOTE:
Turn the torsion spring clockwise and hook
into the proper hole a in the crankcase.
Kick idle gear
1. Install:
lKick idle gear 1
lPlain washer 2
lCirclip 3
NOTE:
lInstall the kick idle gear with its depressed
side a toward you.
lApply the engine oil on the kick idle gear
inner circumference.
New