2001 YAMAHA WR 426F wheel

2 - 33
SPECMAINTENANCE SPECIFICATIONS (WR400F)
NOTE:
- marked portion shall be checked for torque tightening after break-in or before each race.Part to be tightened Thread size Q’tyTightening torque
Nm m·kg ft·lb
Rear brake hose union bolt (master cylinder)M10 ´ 1.25 1 30 3.0 22
Rear wheel axle and nut M20 ´ 1.5 1 125 12.5 90
Driven sprocket and wheel hub M8 ´ 1.25 6 42 4.2 30
Nipple (spoke) — 72 3 0.3 2.2
Disc cover and rear brake caliper M6 ´ 1.0 2 7 0.7 5.1
Protector and rear brake caliper M6 ´ 1.0 2 7 0.7 5.1
Engine mounting:
Engine bracket and frame M8 ´ 1.25 7 34 3.4 24
Engine and frame (front) M10 ´ 1.25 1 69 6.9 50
Engine and frame (upper) M10 ´ 1.25 1 55 5.5 40
Engine and frame (lower) M10 ´ 1.25 1 69 6.9 50
Engine guard (left and right) M8 ´ 1.25 2 23 2.3 17
Pivot shaft and nut M16 ´ 1.5 1 85 8.5 61
Relay arm and swingarm M14 ´ 1.5 1 80 8.0 58
Relay arm and connecting rod M14 ´ 1.5 1 80 8.0 58
Connecting rod and frame M14 ´ 1.5 1 80 8.0 58
Rear shock absorber and frame M10 ´ 1.25 1 56 5.6 40
Rear shock absorber and relay arm M10 ´ 1.25 1 53 5.3 38
Rear frame and frame M8 ´ 1.25 3 29 2.9 21
Swingarm and brake hose holder M5 ´ — 4 4 0.4 2.9
Drive chain tensioner mounting M8 ´ 1.25 2 19 1.9 13
Chain support and swingarm M6 ´ 1.0 3 7 0.7 5.1
Seal guard and swingarm M5 ´ 0.8 4 6 0.6 4.3
Fuel tank mounting M6 ´ 1.0 2 10 1.0 7.2
Fuel tank and fuel cock M6 ´ 1.0 2 7 0.7 5.1
Fuel tank and seat set bracket M6 ´ 1.0 1 7 0.7 5.1
Fuel tank and hooking screw (fitting band) M6 ´ 1.0 1 7 0.7 5.1
Fuel tank and fuel tank bracket M6 ´ 1.0 4 7 0.7 5.1
Seat mounting M8 ´ 1.25 2 23 2.3 17
Side cover mounting M6 ´ 1.0 2 7 0.7 5.1
Air scoop and fuel tank M6 ´ 1.0 4 4 0.4 2.9
Air scoop and radiator panel (lower) M6 ´ 1.0 2 4 0.4 2.9
Front fender mounting M6 ´ 1.0 4 7 0.7 5.1
Rear fender mounting M6 ´ 1.0 4 7 0.7 5.1
Headlight stay (under) and under bracket M6 ´ 1.0 2 7 0.7 5.1
Headlight M6 ´ 1.0 3 7 0.7 5.1
Tail light M6 ´ 1.0 3 4 0.4 2.9
Tail light lead clamp and rear fender M4 ´ 1.59 2 1 0.1 0.7
Coolant reservoir tank M6 ´ 1.0 2 7 0.7 5.1
Sidestand bracket and frame M10 ´ 1.25 2 64 6.4 46
Sidestand mounting M10 ´ 1.25 1 64 6.4 46

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INSP
ADJ

MAINTENANCE INTERVALS
* marked: For USAFRONT FORKS
Inspect and adjust
Replace oil
Replace oil seal
c
cc
c
c
Suspension oil “01”
FRONT FORK OIL SEAL AND DUST
SEAL
Clean and lube
cc
Lithium base grease
REAR SHOCK ABSORBER
Inspect and adjust
Lube
Retighten
c
cc
cc
(After
rain ride)
c
Molybdenum disulfide
grease
CHAIN GUARD AND ROLLERS
Inspect
cc
SWINGARM
Inspect and retighten
cc
RELAY ARM, CONNECTING ROD
Inspect and lube
cc
Molybdenum disulfide
grease
STEERING HEAD
Inspect free play and retighten
Clean and lube
Replace bearing
cc
c
c
Lithium base grease
TIRE, WHEELS
Inspect air pressure, wheel run-out,
tire wear and spoke looseness
Retighten sprocket bolt
Inspect bearings
Replace bearings
Lubricate
c
cc
c
c
cc
Lithium base grease
THROTTLE, CONTROL CABLE
Check routing and connection
Lubricate
c
cc
c
Yamaha cable lube or
SAE 10W-30 motor oil ItemAfter
break-inEvery
race
Every
third
or
500 km
(300 mi)Every
fifth
or
1,000 km
(600 mi)
As re-
quiredRemarks

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INSP
ADJ

PRE-OPERATION INSPECTION AND MAINTENANCE
EC320000
PRE-OPERATION INSPECTION AND MAINTENANCE
Before riding for break-in operation, practice or a race, make sure the machine is in good operating
condition.
Before using this machine, check the following points.
GENERAL INSPECTION AND MAINTENANCE
Item Routine Page
CoolantCheck that coolant is filled up to the radiator filler cap.
Check that the coolant level is correct in the coolant reservoir
tank.
Check the cooling system for leakage.P.3-5 ~ 9
FuelCheck that a fresh gasoline is filled in the fuel tank. Check the
fuel line for leakage.P.1-13
Engine oilCheck that the oil level is correct. Check the crankcase and
frame oil line for leakage.P.3-14 ~ 18
Gear shifter and clutchCheck that gears can be shifted correctly in order and that the
clutch operates smoothly.P.3-10
Throttle grip/HousingCheck that the throttle grip operation and free play are correctly
adjusted. Lubricate the throttle grip and housing, if necessary.P.3-10 ~ 11
Brakes Check the play of front brake and effect of front and rear brake. P.3-26 ~ 32
ChainCheck chain slack and alignment. Check that the chain is lubri-
cated properly.P.3-33 ~ 35
WheelsCheck for excessive wear and tire pressure. Check for loose
spokes and have no excessive play.P.3-42 ~ 44
SteeringCheck that the handlebar can be turned smoothly and have no
excessive play.P.3-44 ~ 45
Front forks and rear shock
absorberCheck that they operate smoothly and there is no oil leakage. P.3-35 ~ 42
Cables (wires)Check that the clutch and throttle cables move smoothly. Check
that they are not caught when the handlebars are turned or
when the front forks travel up and down.—
Muffler Check that the muffler is tightly mounted and has no cracks. —
Sprocket Check that the driven sprocket tightening bolt is not loose. P.3-33
Lubrication Check for smooth operation. Lubricate if necessary. P.3-46
Bolts and nuts Check the chassis and engine for loose bolts and nuts. P.1-18
Lead connectorsCheck that the CDI magneto, CDI unit, and ignition coil are con-
nected tightly.P.1-6
SettingsIs the machine set suitably for the condition of the racing course
and weather or by taking into account the results of test runs
before racing? Are inspection and maintenance completely
done?P.7-1 ~ 22

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INSP
ADJ
REAR BRAKE PAD INSPECTION AND REPLACEMENT
3. Inspect:
lBrake fluid level
Refer to “BRAKE FLUID LEVEL
INSPECTION” section.
lInstall the pad pin plug B.
T R..
Pad pin plug:
3 Nm (0.3 m • kg, 2.2 ft • lb)
4. Check:
lBrake lever operation
A softy or spongy feeling ® Bleed
brake system.
Refer to “BRAKE SYSTEM AIR
BLEEDING” section.
EC366060
REAR BRAKE PAD INSPECTION AND
REPLACEMENT
1. Inspect:
lBrake pad thickness a
Out of specification ® Replace as a
set.
2. Replace:
lBrake pad
Brake pad thickness a:
Standard
6.4 mm (0.25 in) 1.0 mm (0.04 in)
Brake pad replacement steps:
lRemove the protector 1 and pad pin plug
2.
lLoosen the pad pin 3.
lRemove 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
lRemove the pad pin 6 and brake pads 7.
lConnect the transparent hose 8 to the
bleed screw 9 and place the suitable con-
tainer under its end.
lLoosen the bleed screw and push the cali-
per piston in.
CAUTION:
Do not reuse the drained brake fluid.
lTighten the bleed screw.
T R..
Bleed screw:
6 Nm (0.6 m • kg, 4.3 ft • lb)
lInstall the brake pad 0 and pad pin A.
NOTE:
lInstall the brake pads with their projec-
tions a into the caliper recesses b.
lTemporarily tighten the pad pin at this
point.
lInstall the caliper B and rear wheel C.
Refer to “FRONT WHEEL AND REAR
WHEEL” section in the CHAPTER 5.
lTighten the pad pin D.
T R..
Pad pin:
18 Nm (1.8 m • kg, 13 ft • lb)
lInstall 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
ADJ
DRIVE CHAIN SLACK ADJUSTMENT
5. Install:
lDrive chain 1
lJoint 2
lMaster link clip 3
CAUTION:
Be sure to install the master link clip to the
direction as shown.
aTurning direction
6. Lubricate:
lDrive chain
Drive chain lubricant:
SAE 10W-30 motor oil or suit-
able chain lubricants
New
EC36A060
DRIVE CHAIN SLACK ADJUSTMENT
1. Elevate the rear wheel by placing the
suitable stand under the engine.
2. Check:
lDrive chain slack a
Above the seal guard installation bolt.
Out of specification ® Adjust.
NOTE:
Before checking and/or adjusting, rotate the
rear wheel through several revolutions and
check the slack several times to find the tight-
est point. Check and/or adjust chain slack with
rear wheel in this “tight chain” position.
Drive chain slack:
40 ~ 50 mm (1.6 ~ 2.0 in)

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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.)
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.
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.
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 - 39
INSP
ADJREAR SHOCK ABSORBER SPRING PRELOAD
ADJUSTMENT
EC36M013
REAR SHOCK ABSORBER SPRING
PRELOAD ADJUSTMENT
1. Elevate the rear wheel by placing the
suitable stand under the engine.
2. Remove:
lRear frame
3. Loosen:
lLocknut 1
4. Adjust:
lSpring preload
By turning the adjuster 2.
* For EUROPE
NOTE:
lBe sure to remove all dirt and mud from
around the locknut and adjuster before
adjustment.
lThe length of the spring (installed) changes
1.5 mm (0.06 in) per turn of the adjuster.
CAUTION:
Never attempt to turn the adjuster beyond
the maximum or minimum setting.
5. Tighten:
lLocknut
6. Install:
lRear frame Stiffer ® Increase the spring preload.
(Turn the adjuster 2 in.)
Softer ® Decrease the spring preload.
(Turn the adjuster 2 out.)
Spring length (installed) a:
Standard lengthExtent of adjustment
241 mm (9.49 in)
*244 mm (9.61 in)240.5 ~ 258.5 mm
(9.47 ~ 10.18 in)
T R..29 Nm (2.9 m · kg, 21 ft · lb)