2016 YAMAHA WR 450F wheel

PRE-OPERATION INSPECTION AND MAINTENANCE
3-9
EAS2GC1079
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.
EAS2GC1080GENERAL INSPECTION AND MAINTENANCE
TIP
Perform usual maintenance enough so that, in the race course, a confirmation of that and simple set-
ting adjustments may only be left, in order to get enough time to use effectively.ITEM inspect Page
Coolant Check that coolant is filled up to the radiator cap.
Check the cooling system for leakage. 3-10 – 12
Fuel Check that a fresh gasoline is filled in the fuel tank.
Check the fuel line for leakage. 1-28
Engine oil Check that the oil level is correct. Check the crank-
case and oil line for leakage. 3-16 – 18
Gear shifter and clutch Check that gears can be shifted correctly in order and
that the clutch operates smoothly. 3-12 – 13
Throttle grip/Housing Check that the throttle grip operation and free play
are correctly adjusted. Lubricate the throttle grip and
housing, if necessary. 3-13 – 14
Brakes Check the play of front brake and effect of front and
rear brake. 3-25 – 31
Drive chain Check drive chain slack and alignment. Check that
the drive chain is lubricated properly. 3-31
5-69 – 70
Wheels Check for excessive wear and tire pressure. Check
for loose spokes and have no excessive play. 3-36 – 37
Steering Check that the handlebar can be turned smoothly and
have no excessive play. 3-37 – 38
Front forks and rear
shock absorber Check that they operate smoothly and there is no oil
leakage.
3-31 – 36
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.
—
Exhaust pipe Check that the exhaust pipe is tightly mounted and
has no cracks. 3-15 – 16
Rear wheel sprocket Check that the rear wheel sprocket tightening bolt is
not loose. 5-10 – 11
Lubrication Check for smooth operation. Lubricate if necessary. 3-14
3-38 – 39
Bolts and nuts Check the chassis and engine for loose bolts and
nuts. 1-32 – 33
Lead connectors Check that the AC magneto, ECU and ignition coil are
connected tightly. 1-9 – 12
Settings Is the machine set suitably for the condition of the rac-
ing course and weather or by taking into account the
results of test runs before racing? Are inspection and
maintenance completely done?
4-1 – 8

CHASSIS
3-25
EAS2GC1101
CHASSIS
EAS2GC1102BLEEDING THE BRAKE SYSTEMEWA
WARNING
Bleed the brake system whenever:
• The system is disassembled.
• A brake hose is loosened, disconnected, or replaced.
• The brake fluid level is very low.
• Brake operation is faulty.
1. Remove: • Brake master cylinder cap
• Reservoir diaphragm
• Reservoir float (front brake)
• Protector (rear brake)
TIP
• Be careful not to spill any brake fluid or allow the reservoir to overflow.
• Make sure that there is enough brake fluid be-
fore applying the brake. Ignoring this precau-
tion could allow air to enter the brake system,
considerably lengthening the bleeding proce-
dure.
• If bleeding is difficult, it may be necessary to let the brake fluid settle for a few hours. Re-
peat the bleeding procedure when the tiny
bubbles in the hose have disappeared.
2. Bleed the brake system.
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a. Fill the reservoir to the proper level with the recommended brake fluid.
b. Install the reservoir diaphragm.
c. Connect the plastic hose “1” to the bleed screw “2” securely, and place a container
under the end of the plastic hose. d. Slowly apply the brake several times.
e. Fully pull the brake lever or fully press down
the brake pedal and hold it in position.
f. Loosen the bleed screw.
TIP
Loosening the bleed screw will release the
pressure in the brake caliper and cause the
brake lever to contact the throttle grip or the
brake pedal to fully extend.
g. Tighten the bleed screw and then release the brake lever or brake pedal.
h. Repeat steps (d) to (g) until all of the air bub- bles have disappeared from the brake fluid
in the plastic hose.
TIP
During the procedure, keep adding brake fluid
to the reservoir.
ECA
NOTICE
• Wipe off any brake fluid on the brake discs, tires, wheels, etc.
• Brake fluid may erode painted surfaces or
plastic parts. Always clean up spilled fluid
immediately.
i. Tighten the bleed screw.
j. Pour brake fluid to the reservoir up to the specified level.
Refer to “CHECKING THE BRAKE FLUID
LEVEL” on page 3-30.
EWA
WARNING
After bleeding the hydraulic brake system,
check the brake operation.
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1
2
A
A. Front
B. Rear
Bleed screw
6 Nm (0.6 m·kgf, 4.3 ft·lbf)
2
1B
T R..

CHASSIS
3-29
EAS2GC1107CHECKING THE REAR BRAKE PADS
1. Measure:• Brake pad thickness “a”Out of specification  Replace as a set.
TIP
The pads worn up to the indicator “b” grooves
mean that the brake pad thickness limit is
reached.
2. Replace:
• Brake pads
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a. Remove the protector “1” and the pad pin
plug “2”.
b. Loosen the pad pin “3”.
c. Remove the rear wheel “4” and the brake caliper “5”.
Refer to “REAR WHEEL” on page 5-9. d. Remove the pad pin “6” and the brake pads
“7”.
e. Connect the plastic hose “8” to the bleed screw “9” and place a container under the
end of the plastic hose.
f. Loosen the bleed screw and push the brake caliper piston in.EWA
WARNING
Do not reuse the drained brake fluid.
g. Tighten the bleed screw.
h. Install the brake pad “10” and the pad pin “11”.
TIP
• Install the brake pads with their projections “a” into the brake caliper recesses “b”.
• Temporarily tighten the pad pin at this point.
Brake pad lining thickness
6.4 mm (0.25 in)
Limit 1.0 mm (0.04 in)
b a
a
1
2
3
4
5
Bleed screw 6 Nm (0.6 m·kgf, 4.3 ft·lbf)
7
6
9
8
T R..
10
11
a
b

CHASSIS
3-30
i. Install the brake caliper “12” and the rear wheel “13”.
Refer to “REAR WHEEL” on page 5-9.
j. Tighten the pad pin “14”.
k. Install the pad pin plug “15” and the protector “16”.
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3. Check:• Brake fluid levelRefer to “CHECKING THE BRAKE FLUID
LEVEL” on page 3-30.
4. Check: • Brake pedal operationA softy or spongy feeling  Bleed the brake
system.
Refer to “BLEEDING THE BRAKE SYS-
TEM” on page 3-25.
EAS2GC1108CHECKING THE REAR BRAKE PAD INSU-
LATOR
1. Remove: • Brake padsRefer to “REAR BRAKE” on page 5-23. 2. Check:
• Rear brake pad insulator “1”Damage  Replace.
EAS2GC1109CHECKING THE BRAKE FLUID LEVEL
1. Stand the vehicle upright on a level surface.
TIP
In order to ensure a correct reading of the brake
fluid level, make sure that the top of the brake
fluid reservoir is horizontal.
2. Check:
• Brake fluid levelThe minimum level mark “a” or below 
Add.
EWA
WARNING
• Use only the designated brake fluid. Other brake fluids may cause the rubber seals to
deteriorate, causing leakage and poor
brake performance.
• Refill with the same type of brake fluid that
is already in the system. Mixing brake flu-
ids may result in a harmful chemical reac-
tion, leading to poor brake performance.
Pad pin
17 Nm (1.7 m·kgf, 12 ft·lbf)
Pad pin plug 2.5 Nm (0.25 m·kgf, 1.8 ft·lbf)
Bolt (protector) 7 Nm (0.7 m·kgf, 5.1 ft·lbf)
T R..
13
14
12
T R..
15 16
Specified brake fluidDOT 4
A. Front brake
B. Rear brake

CHASSIS
3-31
• When refilling, be careful that water does not enter the brake fluid reservoir. Water
will significantly lower the boiling point of
the brake fluid and could cause vapor
lock.
ECA
NOTICE
Brake fluid may damage painted surfaces
and plastic parts. Therefore, always clean
up any spilt brake fluid immediately.
EAS2GC1110ADJUSTING THE DRIVE CHAIN SLACKECA
NOTICE
A drive chain that is too tight will overload
the engine and other vital parts, and one
that is too loose can skip and damage the
swingarm or cause an accident. Therefore,
keep the drive chain slack within the speci-
fied limits.
1. Use a suitable stand to raise the rear wheel off the ground.
EWA
WARNING
Securely support the vehicle so that there is
no danger of it falling over.
2. Shift the transmission into the neutral posi-
tion.
3. Pull the drive chain up above the drive chain guide installation bolt with a force of about
50 N (5.0 kgf, 36 lbf).
4. Check: • Drive chain slack “a”
Out of specification  Regulate.
TIP
Measure drive chain slack between the drive
chain guide and the bottom of the chain as
shown. 5. Adjust:
• Drive chain slack
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a. Loosen the wheel axle nut “1”.
b. Loosen both locknuts “2”.
c. Turn the adjusting bolt “3” in direction “a” or “b” until the specified drive chain slack is ob-
tained.
TIP
• To maintain the proper wheel alignment, ad-just both sides evenly.
• Push the rear wheel forward to make sure that
there is no clearance between the swingarm
end plates and the ends of the swingarm.
d. Tighten the locknut.
e. Tighten the wheel axle nut.
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EAS2GC1111CHECKING THE FRONT FORK LEGS
1. Stand the vehicle upright on a level surface.
EWA
WARNING
Securely support the vehicle so that there is
no danger of it falling over.
2. Check: • Inner tubeDamage/scratches  Replace.
• Front fork leg (s) Oil leaks between inner tube and outer tube
 Replace the oil seal.
Drive chain slack (on a suitable
stand)
50.0–60.0 mm (1.97–2.36 in)
a
Direction “a”The drive chain slack decreases.
Direction “b” The drive chain slack increases.
Locknut21 Nm (2.1 m·kgf, 15 ft·lbf)
Wheel axle nut 125 Nm (12.5 m·kgf, 90 ft·lbf)
1
32
a
b
T R..
T R..

CHASSIS
3-32
3. Hold the vehicle upright and apply the front brake.
4. Check:
• Front fork operationPush down hard on the handlebar several
times and check if the front fork rebounds
smoothly.
Unsmooth operation  Correct or replace.
Refer to “FRONT FORK” on page 5-40.
EAS2GC1112CHECKING THE FRONT FORK PROTEC-
TOR GUIDE
1. Check:
• Protector guide “1”Out of specification  Replace.
TIP
The protector guide reaches the limit of its use
when it is worn down to the same height “a” as
of the outer tube circumference.
EAS2GC1113CLEANING THE FRONT FORK OIL SEAL
AND DUST SEAL
1. Remove:
•Protector
• Dust seal “1”
ECA
NOTICE
Be careful not to damage the dust seal and
the inner tube by a driver. 2. Clean:
• Dust seal “a”
• Oil seal “b”
TIP
• Clean the dust seal and oil seal after every
run.
• Apply lithium-soap-based grease on the inner
tube.
EAS2GC1114AIR BLEEDING FROM FRONT FORK
TIP
If the front fork initial movement feels stiff dur-
ing a run, relieve the front fork internal pres-
sure.
1. Use a suitable stand to raise the front wheel off the ground.
EWA
WARNING
Securely support the vehicle so that there is
no danger of it falling over.
2. Remove the air bleed screw “1” and release the internal pressure from the front fork.
1
a
1
LS
a
b

CHASSIS
3-34
EAS2GC1116CHECKING THE SWINGARM OPERATION
1. Check:• Swingarm smooth action
• Swingarm free playRefer to “SWINGARM” on page 5-65.
EAS2GC1117CHECKING THE REAR SUSPENSION
1. Stand the vehicle upright on a level surface.
EWA
WARNING
Securely support the vehicle so that there is
no danger of it falling over.
2. Check:• Rear shock absorber assemblyGas leaks/oil leaks  Replace the rear
shock absorber assembly.
Refer to “REAR SHOCK ABSORBER AS-
SEMBLY” on page 5-58.
3. Check: • Rear shock absorber assembly smooth ac-tion
• Rear suspension link smooth action Sit astride the seat and shake your body up
and down several times to check whether
the rear shock absorber assembly operates
smoothly.
Unsmooth operation  Correct or replace.
Refer to “REAR SHOCK ABSORBER AS-
SEMBLY” on page 5-58.
EAS2GC1118ADJUSTING THE REAR SHOCK ABSORB-
ER ASSEMBLY
Use a suitable stand to raise the rear wheel off
the ground.
EWA
WARNING
Securely support the vehicle so that there is
no danger of it falling over. Spring preload
ECA
NOTICE
Do not turn the adjuster forcibly beyond its
adjusting range.
1. Remove:
• Rear frameRefer to “REAR SHOCK ABSORBER AS-
SEMBLY” on page 5-58.
2. Adjust: • Spring preload
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a. Loosen the locknut “1”.
b. Loosen the adjuster “2” until there is some clearance between the spring and the ad-
juster.
c. Measure the spring free length “a”.
d. Turn the adjuster in the direction of “b” or “c” to make an adjustment.
Direction “b”Spring preload is increased (suspen-
sion is harder).
Direction “c” Spring preload is decreased (suspen-
sion is softer).
Spring preload adjusting positionsMinimum Position in which the spring is
turned in 1.5 mm (0.06 in) from
its free length.
Standard Position in which the spring is
turned in 12 mm (0.47 in) from its
free length.
Maximum Position in which the spring is
turned in 18 mm (0.71 in) from its
free length.

CHASSIS
3-37
2. Tighten:• SpokesUse a spoke nipple wrench “1” for tighten-
ing.
TIP
• Do not give a half turn (180 °) or more for one tightening.
• Make sure that tightening after a break-in is done until the initial looseness in nipples dis-
appears.
• Make sure that tightening is done in stages,
not at a time.
EAS2GC1121CHECKING THE WHEELS
1. Check: • Wheel(s)Damage/out-of-round  Replace.
EWA
WARNING
Never attempt to make any repairs to the
wheel.
TIP
After replacing a tire or a wheel, always bal-
ance the wheel.
EAS2GC1122CHECKING THE WHEEL BEARINGS
1. Check:
• Wheel bearingsRefer to “CHECKING THE FRONT WHEEL”
on page 5-5 and “CHECKING THE REAR
WHEEL” on page 5-10.
EAS2GC1123CHECKING AND ADJUSTING THE STEER-
ING HEAD
1. Use a suitable stand to raise the front wheel off the ground.
EWA
WARNING
Securely support the vehicle so that there is
no danger of it falling over.
2. Check:• Steering head
Grasp the bottom of the front fork legs and
gently rock the front fork.
Blinding/looseness  Adjust the steering
head.
3. Remove: • Handlebar
Refer to “HANDLEBAR” on page 5-33.
• Upper bracket Refer to “STEERING HEAD” on page 5-53.
4. Adjust: • Steering head
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a. Remove the washer “1”.
b. After loosening the ring nut “2” with a steer- ing nut wrench “3”, tighten it to the specified
torque.
TIP
• Set the torque wrench at a right angle to the
steering nut wrench.
• Move the steering to the left and right a couple
of times to check that it moves smoothly.
Spoke nipple wrench (6–7)
90890-01521
Spoke nipple wrench (6–7) YM-01521
Spokes 2.5 Nm (0.25 m·kgf, 1.8 ft·lbf)
1
T R..
1
3
2