Front fork YAMAHA YZ426F 2000 User Guide

3 - 27
INSP
ADJ
FRONT BRAKE PAD INSPECTION AND REPLACEMENT
lLoosen the pad pin 2.
lRemove the brake hose holder 3 and cal-
iper 4 from the front fork.
lRemove the pad pin and brake pads 5.
lConnect the transparent hose 6 to the
bleed screw 7 and place the suitable con-
tainer under its end.
lLoosen the bleed screw and push the cali-
per piston in.
lTighten the bleed screw.
T R..
Bleed screw:
6 Nm (0.6 m • kg, 4.3 ft • lb)
lInstall the brake pads 8 and pad pin.
lInstall the brake hose holder 9 and cali-
per 0 and tighten the pad pin A.
T R..
Bolt (caliper):
23 Nm (2.3 m • kg, 17 ft • lb)
Pad pin:
18 Nm (1.8 m • kg, 13 ft • lb)
CAUTION:
Do not reuse the drained brake fluid.
NOTE:
lInstall the brake pads with their projec-
tions a into the caliper recesses b.
lTemporarily tighten the pad pin at this
point.
NOTE:
Fit the brake hose holder cut c over the
projection d on the front fork and clamp the
brake hose.

3 - 33
INSP
ADJ
FRONT FORK INSPECTION
3. Adjust:
lDrive chain slack
Drive chain slack adjustment steps:
lLoosen the axle nut 1 and locknuts 2.
lAdjust chain slack by turning the adjusters
3.
To tighten ® Turn adjuster 3 counter-
clockwise.
To loosen ® Turn adjuster 3 clockwise
and push wheel forward.
lTurn each adjuster exactly the same
amount to maintain correct axle alignment.
(There are marks a on each side of chain
puller alignment.)
lTighten the axle nut while pushing down
the drive chain.
T R..
Axle nut:
125 Nm (12.5 m • kg, 90 ft • lb)
lTighten the locknuts.
NOTE:
Turn the adjuster so that the chain is in line
with the sprocket, as viewed from the rear.
CAUTION:
Too small chain slack will overload the
engine and other vital parts; keep the
slack within the specified limits.
EC36C000
FRONT FORK INSPECTION
1. Inspect:
lFront fork smooth action
Operate the front brake and stroke the
front fork.
Unsmooth action/oil leakage ® Repair
or replace.

3 - 34
INSP
ADJFRONT FORK OIL SEAL AND DUST SEAL CLEANING/
FRONT FORK REBOUND DAMPING FORCE ADJUSTMENT
EC36D001
FRONT FORK OIL SEAL AND DUST SEAL
CLEANING
1. Remove:
lProtector
lDust seal 1
NOTE:
Use a thin screw driver, and be careful not to
damage the inner fork tube and dust seal.
2. Clean:
lDust seal a
lOil seal b
NOTE:
lClean the dust seal and oil seal after every
run.
lApply the lithium soap base grease on the
inner tube.
EC36H002
FRONT FORK REBOUND DAMPING FORCE
ADJUSTMENT
1. Adjust:
lRebound damping force
By turning the adjuster 1.
lSTANDARD POSITION:
This is the position which is back by the spe-
cific number of clicks from the fully turned-in
position. Stiffer a ®Increase the rebound damp-
ing force. (Turn the adjuster
1 in.)
Softer b ®Decrease the rebound damp-
ing force. (Turn the adjuster
1 out.)
Extent of adjustment
Maximum Minimum
Fully turned in
position20 clicks out (from
maximum posi-
tion)
Standard position:
9 clicks out

3 - 35
INSP
ADJFRONT FORK COMPRESSION DAMPING FORCE
ADJUSTMENT
CAUTION:
Do not force the adjuster past the minimum
or maximum extent of adjustment. The
adjuster may be damaged.
WARNING
Always adjust each front fork to the same
setting. Uneven adjustment can cause poor
handling and loss of stability.
EC36J001
FRONT FORK COMPRESSION DAMPING
FORCE ADJUSTMENT
1. Remove:
lRubber cap
2. Adjust:
lCompression damping force
By turning the adjuster 1.
Stiffer a ®Increase the compression
damping force. (Turn the
adjuster 1 in.)
Softer b ®Decrease the compression
damping force. (Turn the
adjuster 1 out.)
Extent of adjustment
Maximum Minimum
Fully turned in
position20 clicks out (from
maximum posi-
tion)

3 - 36
INSP
ADJ
REAR SHOCK ABSORBER INSPECTION
lSTANDARD POSITION:
This is the position which is back by the spe-
cific number of clicks from the fully turned-in
position.
* For EUROPE
CAUTION:
Do not force the adjuster past the minimum
or maximum extent of adjustment. The
adjuster may be damaged.
WARNING
Always adjust each front fork to the same
setting. Uneven adjustment can cause poor
handling and loss of stability.
3. Install:
lRubber cap
T R..
Standard position:
8 clicks out
*10 clicks out
EC36K000
REAR SHOCK ABSORBER INSPECTION
1. Inspect:
lSwingarm smooth action
Abnormal noise/unsmooth action ®
Grease the pivoting points or repair the
pivoting points.
Damage/oil leakage ® Replace.

3 - 42
INSP
ADJ
STEERING HEAD INSPECTION AND ADJUSTMENT
2. Inspect:
lBearing free play
Exist play ® Replace.
EC36U012
STEERING HEAD INSPECTION AND
ADJUSTMENT
1. Elevate the front wheel by placing a suit-
able stand under the engine.
2. Check:
lSteering shaft
Grasp the bottom of the forks and gen-
tly rock the fork assembly back and
forth.
Free play ® Adjust steering head.
3. Check:
lSteering smooth action
Turn the handlebar lock to lock.
Unsmooth action ® Adjust steering ring
nut.
4. Adjust:
lSteering ring nut
Steering ring nut adjustment steps:
lRemove the number plate.
lRemove the handlebar and handle crown.
lLoosen the ring nut 1 using the ring nut
wrench 2.
Ring nut wrench:
YM-33975/90890-01403

5 - 6
CHASFRONT WHEEL AND REAR WHEEL
5. Install:
lWheel axle 1
NOTE:
Apply the lithium soap base grease on the
wheel axle.
6. Install:
lNut (wheel axle) 1
T R..105 Nm (10.5 m · kg, 75 ft · lb)
7. Tighten:
lBolt (axle holder) 1
NOTE:
Before tightening the bolt, fit the wheel axle to
the axle holder by stroking the front fork sev-
eral times with the front brake applied.
8. Install:
lBrake hose 1
To brake hose holder 2.
NOTE:
Before tightening the bolt (brake hose holder),
pass the brake hose in front of the axle boss
a, then fit it into the hose groove b so that the
brake hose does not contact the nut (wheel
axle).
T R..23 Nm (2.3 m · kg, 17 ft · lb)
T R..10 Nm (1.0 m · kg, 7.2 ft · lb)

5 - 18
CHASFRONT BRAKE AND REAR BRAKE
2. Install:
lCopper washer 1
lUnion bolt 2
WARNING
Always use new copper washers.
ACHTUNG:CAUTION:
Install the brake hose so that its pipe por-
tion a directs as show and lightly touches
the projection b on the caliper.
New
T R..30 Nm (3.0 m · kg, 22 ft · lb)
3. Install:
lBrake hose holder 1
lCaliper 2
lBolt (caliper) 3
NOTE:
Fit the brake hose holder cut a over the pro-
jection b on the front fork and clamp the brake
hose.
4. Tighten:
lPad pin 4
5. Install:
lPad pin plug 5
T R..23 Nm (2.3 m · kg, 17 ft · lb)
T R..18 Nm (1.8 m · kg, 13 ft · lb)
T R..3 Nm (0.3 m · kg, 2.2 ft · lb)
EC5A5100
Rear caliper
1. Install:
lPad support 1
lBrake pad 2
lPad pin 3
NOTE:
lInstall the brake pads with their projections
a into the caliper recesses b.
lTemporarily tighten the pad pin at this point.

5 - 27
CHASFRONT FORK
EC550000
FRONT FORK
Extent of removal:1 Front fork removal
Extent of removal Order Part name Q’ty Remarks
Preparation for removalFRONT FORK REMOVAL
Hold the machine by placing the
suitable stand under the engine.
Front wheel Refer to “FRONT WHEEL AND REAR
WHEEL” section.
Front caliper Refer to “FRONT BRAKE AND REAR
BRAKE” section.
Number plate
1 Protector 1
2 Brake hose holder 2
3 Pinch bolt (handle crown) 2 Only loosening.
4 Cap bolt 1Loosen when disassembling the front fork.
5 Pinch bolt (under bracket) 2 Only loosening.
6 Front fork 1
WARNING
Support the machine securely so there is nodanger of it falling over.
1

5 - 28
CHASFRONT FORK
EC558000
FRONT FORK DISASSEMBLY
Extent of removal:1 Oil seal removal2 Damper rod removal
Extent of removal Order Part name Q’ty Remarks
FRONT FORK DISASSEMBLY
1 Cap bolt 1 Refer to “REMOVAL POINTS”.
2 Fork spring 1 Drain the folk oil.
3 Dust seal 1
Refer to “REMOVAL POINTS”. 4 Stopper ring 1
5 Inner tube 1
6 Outer tube 1
7 Piston metal 1
8 Slide metal 1
9 Plain washer 1
0 Oil seal 1
A Spring guide 1
B Base valve 1 Use special tool.
C Damper rod 1Refer to “REMOVAL POINTS”.
1
2