bolt pattern YAMAHA WR 426F 2001 Owners Manual

3 - 21
INSP
ADJ
VALVE CLEARANCE ADJUSTMENT
5. Adjust:
lValve clearance
Adjustment steps:
lLoosen the timing chain tensioner cap
bolt.
lRemove the timing chain tensioner and
camshaft caps.
NOTE:
Remove the camshaft cap bolts in a criss-
cross pattern from the outside working
inwards.
lRemove the camshaft (intake 1 and
exhaust 2).
NOTE:
Attach a wire 3 to the timing chain to pre-
vent it from falling into the crankcase.
lRemove the decompression guide 4,
cable 5, bolt 6 and decompression shaft
7.
lRemove the valve lifters 8 and the pads
9.
NOTE:
lPlace a rag in the timing chain space to
prevent pads from falling into the crank-
case.
lIdentity each valve lifter and pad position
very carefully so that they can be rein-
stalled in their original place.
lSelect the proper pad using the pad
selecting table.
Pad rangePad Availability:
25 increments
No. 120
~
No. 2401.20 mm
~
2.40 mmPads are available in
0.05 mm increments
NOTE:
The thickness a of each pad is indicated in
hundreths of millimeters on the pad upper
surface.

4 - 23
ENGCAMSHAFTS
REMOVAL POINTS
Camshaft
1. Remove:
lTiming plug 1
lStraight plug 2
2. Align:
l“I” mark
With stationary pointer.
Checking steps:
lTurn the crankshaft counterclockwise with
a wrench.
lAlign the “I” mark a on the rotor with the
stationary pointer b on the crankcase
cover. When the “I” mark is aligned with
the stationary pointer, the piston is at the
Top Dead Center (T.D.C.).
NOTE:
lIn order to be sure that the piston is at Top
Dead Center, the punch mark c on the
exhaust camshaft and the punch mark d
on the intake camshaft must align with the
cylinder head surface, as shown in the
illustration.
lIf there is no clearance, rotate the crank-
shaft counterclockwise one turn.
3. Loosen:
lTensioner cap bolt 1
4. Remove:
lTiming chain tensioner 2
5. Remove:
lBolt (camshaft cap) 1
lCamshaft caps 2
NOTE:
Remove the bolts (camshaft cap) in a criss-
cross pattern, working from the outside in.
CAUTION:
The bolts (camshaft cap) must be removed
evenly to prevent damage to the cylinder
head, camshafts or camshaft caps.

4 - 25
ENGCAMSHAFTS
4. Measure:
lCamshaft-to-cap clearance
Out of specification ® Measure bearing
diameter (camshaft)
Camshaft-to-cap clearance:
0.020 ~ 0.054 mm
(0.0008 ~ 0.0021 in)
: 0.08 mm (0.003 in)
Measurement steps:
lInstall the camshaft onto the cylinder
head.
lPosition a strip of Plastigauge® 1 onto the
camshaft.
lInstall the circlip, dowel pins and camshaft
caps.
T R..
Bolt (camshaft cap):
10 Nm (1.0 m • kg, 7.2 ft • lb)
NOTE:
l.Tighten the bolts (camshaft cap) in a
crisscross pattern from innermost to outer
caps.
lDo not turn the camshaft when measuring
clearance with the Plastigauge®.
lRemove the camshaft caps and measure
the width of the Plastigauge
® 1.
5. Measure:
lBearing diameter (camshaft) a
Out of specification ® Replace the
camshaft.
Within specification ® Replace cam-
shaft case and camshaft caps as a set.
Camshaft sprocket
1. Inspect:
lCamshaft sprocket 1
Wear/damage ® Replace the camshaft
assembly and timing chain as a set.
Bearing diameter (camshaft):
21.967 ~ 21.980 mm
(0.8648 ~ 0.8654 in)
1

4 - 27
ENGCAMSHAFTS
2. Install:
lTiming chain tensioner
3. Turn:
lCrankshaft
Counterclockwise several turns
4. Check:
lRotor “I” mark
Align with the crankcase stationary
pointer.
lCamshaft match marks
Align with the cylinder head surface.
Out of alignment ® Adjust.
lInstall the dowel pins, clips and camshaft
caps 4.
T R..
Bolt (camshaft cap):
10 Nm (1.0 m • kg, 7.2 ft • lb)
NOTE:
Tighten the bolts (camshaft cap) 5 in a
crisscross pattern.
CAUTION:
The bolts (camshaft cap) must be tight-
ened evenly or damage to the cylinder
head, camshaft caps and camshaft will
result.
Installation steps:
lWhile pressing the tensioner rod lightly
with fingers, use a thin screwdriver and
wind the tensioner rod up fully clockwise.
lWith the rod fully wound and the chain
tensioner UP mark a facing upward,
install the gasket 1 and the chain ten-
sioner 2, and tighten the bolt 3 to the
specified torque.
T R..
Bolt (timing chain tensioner):
10 Nm (1.0 m • kg, 7.2 ft • lb)
lRelease the screwdriver, check the ten-
sioner rod to come out and tighten the
gasket 4 and the cap bolt 5 to the speci-
fied torque.
T R..
Tensioner cap bolt:
7 Nm (0.7 m • kg, 5.1 ft • lb)

4 - 54
ENGCLUTCH (WR426F)
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 - 61
ENGCLUTCH (WR400F)
8. 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)
9. Install:
lGasket (clutch cover) 1
lDowel pin 2
New
10. 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 - 66
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 - 86
ENGCDI MAGNETO
4. Connect:
lCDI magneto lead
Refer to “CABLE ROUTING DIA-
GRAM” section in the CHAPTER 2.
5. Install:
lGasket [crankcase cover (left)]
lCrankcase cover (left) 1
lHose holder (cylinder head breather
hose) 2
lBolt [crankcase cover (left)]
NOTE:
Tighten the screws in stage, using a crisscross
pattern.
New
T R..10 Nm (1.0 m · kg, 7.2 ft · lb)
6. Install:
lShift pedal 1
lBolt (shift pedal)
NOTE:
When installing the shift pedal onto the shift
shaft, be sure that the center of the shift pedal
is about 2 mm a above the top of the footrest.
7. Install:
lEngine guard (left) 1
lHose holder (cylinder head breather
hose) 2
lBolt [engine guard (left)]
1
2
T R..23 Nm (2.3 m · kg, 17 ft · lb)

4 - 100
ENGCRANKCASE AND CRANKSHAFT
6. Tighten:
lHose guide 1
lClutch cable holder 2
lBolt (crankcase)
NOTE:
Tighten the crankcase tightening bolts in
stage, using a crisscross pattern.
T R..12 Nm (1.2 m · kg, 8.7 ft · lb)
7. Install:
lOil delivery pipe
lO-ring
lBolt (oil delivery pipe)
8. Install:
lTiming chain
lTiming chain guide (rear)
lBolt (timing chain guide)
9. Remove:
lSealant
Forced out on the cylinder mating sur-
face.
10. Apply:
lEngine oil
To the crank pin, bearing and oil deliv-
ery hole.
11. Check:
lCrankshaft and transmission operation.
Unsmooth operation ® Repair.
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 - 5
CHAS

FRONT WHEEL AND REAR WHEEL
EC595000
ASSEMBLY AND INSTALLATION
Front wheel
1. Install:
l
Bearing (left)
1

l
Spacer
2

l
Bearing (right)
3

l
Oil seal
4

NOTE:

l
Apply the lithium soap base grease on the
bearing and oil seal lip when installing.
l
Use a socket that matches the outside diam-
eter of the race of the bearing.
l
Left side of bearing shall be installed first.
l
Install the oil seal with its manufacture’s
marks or numbers facing outward.
CAUTION:
Do not strike the inner race of the bearing.
Contact should be made only with the outer
race.
2. Install:
lBrake disc 1
lBolt (brake disc) 2
NOTE:
Tighten the bolts in stage, using a crisscross
pattern.
New
T R..12 Nm (1.2 m · kg, 8.7 ft · lb)
3. Install:
lCollar 1
NOTE:
lApply the lithium soap base grease on the oil
seal lip.
lInstall the collar with their projection a fac-
ing the wheel.
4. Install:
lTrip meter gear unit 1
NOTE:
Make sure the two projections a in the wheel
hub are meshed with the two slots b in the trip
meter gear unit.b a1