2002 YAMAHA YZ426F brake

3 - 26
INSP
ADJREAR BRAKE ADJUSTMENT/
FRONT BRAKE PAD INSPECTION AND REPLACEMENT
EC364002
REAR BRAKE ADJUSTMENT
1. Check:
Brake pedal height a
Out of specification → Adjust.
Brake pedal height a:
5 mm (0.20 in)
2. Adjust:
Brake pedal height
Pedal height adjustment steps:
Loosen the locknut 1.
Turn the adjusting nut 2 until the pedal
height a is within specified height.
Tighten the locknut.
WARNING
Adjust the pedal height between the
maximum Å and the minimum ı as
shown. (In this adjustment the bolt 3
end b should protrude out of the lower
adjusting nut 4 but not be less than
2 mm (0.08 in) c away from the brake
pedal 5).
After the pedal height adjustment, make
sure that the rear brake does not drag.
Å
ı
EC365080
FRONT BRAKE PAD INSPECTION AND
REPLACEMENT
1. Inspect:
Brake pad thickness a
Out of specification → Replace as a
set.
2. Replace:
Brake pad
Brake pad thickness a:
Standard
4.4 mm (0.17 in) 1.0 mm (0.04 in)
Brake pad replacement steps:
Remove the pad pin plug 1.

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

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INSP
ADJ
REAR BRAKE PAD INSPECTION AND REPLACEMENT
3. Inspect:
Brake fluid level
Refer to “BRAKE FLUID LEVEL
INSPECTION” section.
4. Check:
Brake lever operation
A softy or spongy feeling → Bleed
brake system.
Refer to “BRAKE SYSTEM AIR
BLEEDING” section.
Install the pad pin plug B.
T R..
Pad pin plug:
3 Nm (0.3 m • kg, 2.2 ft • lb)
EC366060
REAR BRAKE PAD INSPECTION AND
REPLACEMENT
1. Inspect:
Brake pad thickness a
Out of specification → Replace as a
set.
2. Replace:
Brake pad
Brake pad thickness a:
Standard
6.4 mm (0.25 in) 1.0 mm (0.04 in)
Brake pad replacement steps:
Remove the protector 1 and pad pin plug
2.
Loosen the pad pin 3.
Remove the rear wheel 4 and caliper 5.
Refer to “FRONT WHEEL AND REAR
WHEEL” section in the CHAPTER 5.

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INSP
ADJ
REAR BRAKE PAD INSPECTION AND REPLACEMENT
Remove the pad pin 6 and brake pads 7.
Connect the transparent hose 8 to the
bleed screw 9 and place the suitable con-
tainer under its end.
Loosen the bleed screw and push the cali-
per piston in.
CAUTION:
Do not reuse the drained brake fluid.
Tighten the bleed screw.
T R..
Bleed screw:
6 Nm (0.6 m • kg, 4.3 ft • lb)
Install the brake pad 0 and pad pin A.
NOTE:
Install the brake pads with their projec-
tions a into the caliper recesses b.
Temporarily tighten the pad pin at this
point.
Install the caliper B and rear wheel C.
Refer to “FRONT WHEEL AND REAR
WHEEL” section in the CHAPTER 5.
Tighten the pad pin D.
T R..
Pad pin:
18 Nm (1.8 m • kg, 13 ft • lb)
Install the pad pin plug E and protector F.
T R..
Pad pin plug:
3 Nm (0.3 m • kg, 2.2 ft • lb)
Bolt (protector):
7 Nm (0.7 m • kg, 5.1 ft • lb)

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INSP
ADJREAR BRAKE PAD INSULATOR INSPECTION/
BRAKE FLUID LEVEL INSPECTION
3. Inspect:
Brake fluid level
Refer to “BRAKE FLUID LEVEL
INSPECTION” section.
4. Check:
Brake pedal operation
A softy or spongy feeling → Bleed
brake system.
Refer to “BRAKE SYSTEM AIR
BLEEDING” section.
EC36b000
REAR BRAKE PAD INSULATOR
INSPECTION
1. Remove:
Brake pad
Refer to “REAR BRAKE PAD INSPEC-
TION AND REPLACEMENT” section.
2. Inspect:
Rear brake pad insulator 1
Damage → Replace.
EC367001
BRAKE FLUID LEVEL INSPECTION
1. Place the master cylinder so that its top is
in a horizontal position.
2. Inspect:
Brake fluid level
Fluid at lower level → Fill up.
aLower level
ÅFront
ıRear
WARNING
Use only designated quality brake fluid to
avoid poor brake performance.
Refill with same type and brand of brake
fluid; mixing fluids could result in poor
brake performance.
Be sure that water or other contaminants
do not enter master cylinder when refill-
ing.
Clean up spilled fluid immediately to
avoid erosion of painted surfaces or plas-
tic parts.
Recommended brake fluid:
DOT #4
Å
ı

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INSP
ADJ

FRONT FORK INSPECTION
3. Adjust:

Drive chain slack
Drive chain slack adjustment steps:

Loosen the axle nut
1
and locknuts
2
.

Adjust chain slack by turning the adjusters
3
.
To tighten
→
Turn adjuster
3
counter-
clockwise.
To loosen
→
Turn adjuster
3
clockwise
and push wheel forward.

Turn each adjuster exactly the same
amount to maintain correct axle alignment.
(There are marks
a
on each side of chain
puller alignment.)
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.

Tighten the axle nut while pushing down
the drive chain.
T R..

Axle nut:
125 Nm (12.5 m • kg, 90 ft • lb)

Tighten the locknuts.
EC36C000
FRONT FORK INSPECTION
1. Inspect:

Front fork smooth action
Operate the front brake and stroke the
front fork.
Unsmooth action/oil leakage
→
Repair
or replace.

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INSP
ADJ
LUBRICATION
LUBRICATION
To ensure smooth operation of all compo-
nents, lubricate your machine during setup,
after break-in, and after every race.
1All control cable
2Clutch lever pivot
3Shift pedal pivot
4Footrest pivot
5Throttle-to-handlebar contact
6Drive chain
7Tube guide cable winding portion
8Throttle cable end
9Clutch cable end
0Decompression cable endÅUse Yamaha cable lube or equivalent on these
areas.
ıUse SAE 10W-30 motor oil or suitable chain
lubricants.
ÇLubricate the following areas with high quality,
lightweight lithium-soap base grease.
CAUTION:
Wipe off any excess grease, and avoid get-
ting grease on the brake discs.
AAA
AAB
CC

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ENGCLUTCH
CLUTCH
CLUTCH
Extent of removal:1 Push rod and push lever removal2 Push pod 1 disassembly
3 Friction plate and clutch plate removal4 Clutch housing removal
Extent of removal Order Part name Q’ty Remarks
CLUTCH REMOVAL
Preparation for removal Drain the engine oil. Refer to “ENGINE OIL REPLACEMENT”
section in the CHAPTER 3.
Brake pedal Refer to “ENGINE REMOVAL” section.
Clutch cable Disconnect at engine side.
1 Clutch cover 1
2 Gasket 1
3 Dowel pin 2
4 Clutch spring 6
5 Pressure plate 1
6 Push rod 1 1
7 Circlip 1
8 Plain washer 1
9 Bearing 1
10 Ball 1
11Push rod 2
1
41
2
3
1