ABS YAMAHA WR 450F 2011 User Guide

3-7
PRE-OPERATION INSPECTION AND MAINTENANCE
PRE-OPERATION INSPECTION AND MAINTENANCE
Before riding for break-in operation or practice, 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 cap. Check the cool-
ing system for leakage.P.3-11 – 12
FuelCheck that a fresh gasoline is filled in the fuel tank. Check the fuel
line for leakage.P.1-18
Engine oilCheck that the oil level is correct. Check the crankcase and oil
line for leakage.P.3-14 – 15
Gear shifter and clutchCheck that gears can be shifted correctly in order and that the
clutch operates smoothly.P.3-12
Throttle grip/HousingCheck that the throttle grip operation and free play are correctly
adjusted. Lubricate the throttle grip and housing, if necessary.P.3-12 – 13
Brakes Check the play of front brake and effect of front and rear brake. P.3-19 – 22
Drive chainCheck drive chain slack and alignment. Check that the drive chain
is lubricated properly.P.3-22 – 23
WheelsCheck for excessive wear and tire pressure. Check for loose
spokes and have no excessive play.P.3-26
SteeringCheck that the handlebar can be turned smoothly and have no ex-
cessive play.P.3-26 – 27
Front forks and rear shock
absorberCheck that they operate smoothly and there is no oil leakage.
P.3-23 – 26
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. P.3-10 – 11
Rear wheel sprocket Check that the rear wheel sprocket tightening bolt is not loose. P.3-22
Lubrication Check for smooth operation. Lubricate if necessary. P.3-28
Bolts and nuts Check the chassis and engine for loose bolts and nuts. P.1-20
Lead connectorsCheck that the AC magneto, CDI unit, and ignition coil are con-
nected tightly.P.1-7
SettingsIs the machine set suitably for the condition of the course and
weather or by taking into account the results of test runs before
riding? Are inspection and maintenance completely done?P.4-1 – 10

3-24
CHASSIS
RELIEVING THE FRONT FORK
INTERNAL PRESSURE
If the front fork initial movement feels
stiff during a run, relieve the front fork
internal pressure.
1. Elevate the front wheel by placing
a suitable stand under the engine.
2. Remove the air bleed screw "1"
and release the internal pressure
from the front fork.
3. Install:
• Air bleed screw
ADJUSTING THE FRONT FORK
REBOUND DAMPING FORCE
1. Adjust:
• Rebound damping force
By turning the adjuster "1".
• STANDARD POSITION:
This is the position which is back
by the specific number of clicks
from the fully turned-in position.
Do not force the adjuster past the
minimum or maximum extent of
adjustment. The adjuster may be
damaged.
Always adjust each front fork to
the same setting. Uneven adjust-
ment can cause poor handling and
loss of stability.
ADJUSTING THE FRONT FORK
COMPRESSION DAMPING FORCE
1. Remove:
• Rubber cap
2. Adjust:
• Compression damping force
By turning the adjuster "1".
• STANDARD POSITION:
This is the position which is back
by the specific number of clicks
from the fully turned-in position.
Do not force the adjuster past the
minimum or maximum extent of
adjustment. The adjuster may be
damaged.
Always adjust each front fork to
the same setting. Uneven adjust-
ment can cause poor handling and
loss of stability.
3. Install:
• Rubber cap
CHECKING THE REAR SHOCK
ABSORBER
1. Inspect:
• Swingarm smooth action
Abnormal noise/unsmooth action
→Grease the pivoting points or
repair the pivoting points.
Damage/oil leakage→Replace.
ADJUSTING THE REAR SHOCK
ABSORBER SPRING PRELOAD
1. Elevate the rear wheel by placing
the suitable stand under the en-
gine.
2. Remove:
• Rear frame
3. Measure:
• Spring fitting length
The I.D. mark "a" is marked at the end
of the spring.
4. Adjust:
• Spring preload
Adjustment steps:
a. Loosen the locknut "1". Air bleed screw:
1 Nm (0.1 m•kg, 0.7
ft•lb)
Stiffer "a" →Increase the re-
bound damping force. (Turn
the adjuster "1" in.)
Softer "b" →Decrease the re-
bound damping force. (Turn
the adjuster "1" out.)
Extent of adjustment:
Maximum Minimum
Fully turned in
position20 clicks out
(from maximum
position)
Standard position:
8 clicks out
Stiffer "a" →Increase the com-
pression damping force. (Turn
the adjuster "1" in.)
Softer "b" →Decrease the com-
pression damping force. (Turn
the adjuster "1" out.)
Extent of adjustment:
Maximum Minimum
Fully turned in
position20 clicks out
(from maximum
position)
Standard position:
9 clicks out
Standard fitting length:
I.D. MARK/Q'TY Length
Pink/1 252.5 mm
(9.94 in)
* 251.5 mm
(9.90 in)
* For EUROPE

3-25
CHASSIS
b. Loosen the adjuster "2" until there
is some clearance between the
spring and adjuster.
c. Measure the spring free length
"a".
d. Turn the adjuster "2".
• Be sure to remove all dirt and mud
from around the locknut and adjust-
er before adjustment.
• The length of the spring (installed)
changes 1.5 mm (0.06 in) per turn
of the adjuster.
Never attempt to turn the adjuster
beyond the maximum or minimum
setting.
e. Tighten the locknut.
5. Install:
• Rear frame (upper)
• Rear frame (lower)ADJUSTING THE REAR SHOCK
ABSORBER REBOUND DAMPING
FORCE
1. Adjust:
• Rebound damping force
By turning the adjuster "1".
• STANDARD POSITION:
This is the position which is back
by the specific number of clicks
from the fully turned-in position.
(Which align the punch mark "a"
on the adjuster with the punch
mark "b" on the bracket.)
Do not force the adjuster past the
minimum or maximum extent of
adjustment. The adjuster may be
damaged.
ADJUSTING THE REAR SHOCK
ABSORBER LOW COMPRESSION
DAMPING FORCE
1. Adjust:
• Low compression damping force
By turning the adjuster "1".
• STANDARD POSITION:
This is the position which is back
by the specific number of clicks
from the fully turned-in position.
(Which align the punch mark "a"
on the adjuster with the punch
mark "b" on the high compression
damping adjuster.)
Do not force the adjuster past the
minimum or maximum extent of
adjustment. The adjuster may be
damaged.
Stiffer →Increase the spring pre-
load. (Turn the adjuster "2" in.)
Softer→Decrease the spring pre-
load. (Turn the adjuster "2"
out.)
Extent of adjustment:
Maximum Minimum
Position in
which the
spring is turned
in 22 mm (0.87
in) from its free
length.Position in
which the
spring is turned
in 1.5 mm (0.06
in) from its free
length.
Locknut:
30 Nm (3.0 m•kg, 22
ft•lb)
Rear frame (upper):
38 Nm (3.8 m•kg, 27
ft•lb)
Rear frame (lower):
32 Nm (3.2 m•kg, 23
ft•lb)Stiffer "a" →Increase the re-
bound damping force. (Turn
the adjuster "1" in.)
Softer "b" →Decrease the re-
bound damping force. (Turn
the adjuster "1" out.)
Extent of adjustment:
Maximum Minimum
Fully turned in
position20 clicks out
(from maximum
position)
Standard position:
About 11 clicks outStiffer "a" →Increase the low
compression damping force.
(Turn the adjuster "1" in.)
Softer "b" →Decrease the low
compression damping force.
(Turn the adjuster "1" out.)
Extent of adjustment:
Maximum Minimum
Fully turned in
position20 clicks out
(from maximum
position)
Standard position:
About 8 clicks out
* About 9 clicks out
** About 11 clicks out
* For AUS, NZ and ZA
** For EUROPE

3-26
CHASSIS
ADJUSTING THE REAR SHOCK
ABSORBER HIGH COMPRESSION
DAMPING FORCE
1. Adjust:
• High compression damping force
By turning the adjuster "1".
• STANDARD POSITION:
This is the position which is back
by the specific number of turns
from the fully turned-in position.
(Which align the punch mark "a"
on the adjuster with the punch
mark "b" on the adjuster body.)
Do not force the adjuster past the
minimum or maximum extent of
adjustment. The adjuster may be
damaged.
CHECKING THE TIRE PRESSURE
1. Measure:
• Tire pressure
Out of specification→Adjust.
• Check the tire while it is cold.
• Loose bead stoppers allow the tire
to slip off its position on the rim
when the tire pressure is low.
• A tilted tire valve stem indicates that
the tire slips off its position on the
rim.
• If the tire valve stem is found tilted,
the tire is considered to be slipping
off its position. Correct the tire posi-
tion.
CHECKING AND TIGHTENING THE
SPOKES
The following procedure applies to all
of the spokes.
1. Check:
• Spokes
Bend/damage→Replace.
Loose spoke→Retighten.
Tap the spokes with a screw-
driver.
A tight spoke will emit a clear, ringing
tone; a loose spoke will sound flat.
2. Tighten:
• Spokes
(with a spoke nipple wrench "1")
Be sure to retighten these spokes be-
fore and after break-in.
CHECKING THE WHEELS
1. Inspect:
• Wheel runout
Elevate the wheel and turn it.
Abnormal runout→ Replace.
2. Inspect:
• Bearing free play
Exist play→Replace.
CHECKING AND ADJUSTING THE
STEERING HEAD
1. Place a stand under the engine to
raise the front wheel off the
ground. WARNING! Securely
support the vehicle so that
there is no danger of it falling
over.
2. Check:
• Steering stem
Grasp the bottom of the forks and
gently rock the fork assembly
back and forth.
Free play→Adjust steering head.
3. Check:
• Steering smooth action
Turn the handlebar lock to lock.
Unsmooth action→Adjust steer-
ing ring nut. Stiffer "a" →Increase the high
compression damping force.
(Turn the adjuster "1" in.)
Softer "b" →Decrease the high
compression damping force.
(Turn the adjuster "1" out.)
Extent of adjustment:
Maximum Minimum
Fully turned in
position2 turns out
(from maximum
position)
Standard position:
About 1-1/8 turns out
* About 1-1/4 turns out
* For AUS, NZ and ZA
Standard tire pressure:
100 kPa (1.0 kgf/cm
2,
15 psi)
Spoke nipple wrench:
YM-01521/90980-01521
Spokes:
3 Nm (0.3 m•kg, 2.2
ft•lb)

4-7
CHASSIS
CHOOSING SET LENGTH
1. Place a stand or block under the
engine to put the rear wheel
above the floor, and measure the
length "a" between the rear wheel
axle center and the rear fender
holding bolt.
2. Remove the stand or block from
the engine and with a rider astride
the seat, measure the sunken
length "b" between the rear wheel
axle center and the rear fender
holding bolt.
3. Loosen the locknut "1" and make
adjustment by turning the spring
adjuster "2" to achieve the stan-
dard figure from the subtraction of
the length "b" from the length "a".
• If the machine is new and after it is
broken in, the same set length of
the spring may change because of
the initial fatigue, etc. of the spring.
Therefore, be sure to make reeval-
uation.
• If the standard figure cannot be
achieved by adjusting the spring
adjuster and changing the spring
set length, replace the spring with
an optional one and make re-ad-
justment.
SETTING OF SPRING AFTER
REPLACEMENT
After replacement, be sure to adjust
the spring to the set length [sunken
length 90–100 mm (3.5–3.9 in)] and
set it.
1. Use of soft spring
• Set the soft spring for less re-
bound damping to compensate
for its less spring load. Run with
the rebound damping adjuster
one or two clicks on the softer
side and readjust it to suit your
preference.
2. Use of stiff spring
• Set the soft spring for more re-
bound damping to compensate
for its greater spring load. Run
with the rebound damping adjust-
er one or two clicks on the stiffer
side and readjust it to suit your
preference.
Adjusting the rebound damping will
be followed more or less by a change
in the compression damping. For cor-
rection, turn the low compression
damping adjuster on the softer side.
When using a rear shock absorber
other than currently installed, use
the one whose overall length "a"
does not exceed the standard as it
may result in faulty performance.
Never use one whose overall
length is greater than standard.
REAR SHOCK ABSORBER
SETTING PARTS
• Rear shock spring "1"
• The I.D. mark "a" is marked at the
end of the spring.
• Spring specification varies accord-
ing to the color and quantity of I.D.
marks.
Standard figure:
90–100 mm (3.5–3.9 in)
Length "a" of standard
shock:
488.5 mm (19.23 in)
TYPESPRI
NG
RAT
ESPRING
PART
NUM-
BER
(-22212-)I.D.
MARK/
Q'TY
SOFT 4.3 5UN-00 Brown/1
4.5 5UN-10 Green/1
4.7 5UN-20 Red/1
4.9 5UN-30 Black/1
5.1 5UN-40 Blue/1
5.3 5UN-50 Yellow/1
STD 5.5 5UN-60 Pink/1
STIFF 5.7 5UN-70 White/1

4-8
CHASSIS
• Extent of adjustment (spring pre-
load)
For the spring preload adjustment, re-
fer to "ADJUSTING THE REAR
SHOCK ABSORBER SPRING PRE-
LOAD" in the CHAPTER 3.
SPRING
PART
NUM-
B E R
(-22212-)Maximum Minimum
5UN-00
5UN-10
5UN-20
5UN-30Position
in which
the spring
is turned
in 20 mm
(0.79 in)
from its
free
length.Position
in which
the spring
is turned
in 1.5 mm
(0.06 in)
from its
free
length. 5UN-40
5UN-50
5UN-60
5UN-70Position
in which
the spring
is turned
in 22 mm
(0.87 in)
from its
free
length.

4-9
CHASSIS
SUSPENSION SETTING (FRONT FORK)
• If any of the following symptoms is experienced with the standard position as the base, make resetting by reference to
the adjustment procedure given in the same chart.
• Before any change, set the rear shock absorber sunken length to the standard figure 90–100 mm (3.5–3.9 in).
SymptomSection
Check Adjust
JumpLarge
gapMedi-
um
gapSmall
gap
Stiff over entire
range○○○Compression damping Turn adjuster counterclockwise (about 2 clicks) to
decrease damping.
Oil level (oil amount) Decrease oil level by about 5–10 mm (0.2–0.4 in).
Spring Replace with soft spring.
Unsmooth move-
ment over entire
range○○○○Outer tube Check for any bends, dents, and other noticeable
scars, etc. If any, replace affected parts.
Inner tube
Under bracket tighten-
ing torqueRetighten to specified torque.
Poor initial move-
ment○Rebound damping Turn adjuster counterclockwise (about 2 clicks) to
decrease damping.
Oil seal Apply grease in oil seal wall.
Soft over entire
range, bottoming
out○○Compression damping Turn adjuster clockwise (about 2 clicks) to in-
crease damping.
Oil level (oil amount) Increase oil level by about 5–10 mm (0.2–0.4 in).
Spring Replace with stiff spring.
Stiff toward stroke
end○Oil level (oil amount) Decrease oil level by about 5 mm (0.2 in).
Soft toward stroke
end, bottoming out○Oil level (oil amount) Increase oil level by about 5 mm (0.2 in).
Stiff initial move-
ment○○○○Compression dampingTurn adjuster counterclockwise (about 2 clicks) to
decrease damping.
Low front, tending to
lower front posture○○Compression damping Turn adjuster clockwise (about 2 clicks) to in-
crease damping.
Rebound damping Turn adjuster counterclockwise (about 2 clicks) to
decrease damping.
Balance with rear end Set sunken length for 95–100 mm (3.7–3.9 in)
when one passenger is astride seat (lower rear
posture).
Oil level (oil amount) Increase oil level by about 5 mm (0.2 in).
"Obtrusive" front,
tending to upper
front posture○○Compression damping Turn adjuster counterclockwise (about 2 clicks) to
decrease damping.
Balance with rear end Set sunken length for 90–95 mm (3.5–3.7 in)
when one passenger is astride seat (upper rear
posture).
Spring Replace with soft spring.
Oil level (oil amount) Decrease oil level by about 5–10 mm (0.2–0.4 in).

4-10
CHASSIS
SUSPENSION SETTING (REAR SHOCK ABSORBER)
• If any of the following symptoms is experienced with the standard position as the base, make resetting by reference to
the adjustment procedure given in the same chart.
• Adjust the rebound damping in 2-click increments or decrements.
• Adjust the low compression damping in 1-click increments or decrements.
• Adjust the high compression damping in 1/6 turn increments or decrements.
SymptomSection
Check Adjust
JumpLarge
gapMedi-
um
gapSmall
gap
Stiff, tending to sink○○Rebound damping Turn adjuster counterclockwise (about 2 clicks) to
decrease damping.
Spring set length Set sunken length for 90–100 mm (3.5–3.9 in)
when one passenger is astride seat.
Spongy and unsta-
ble○○Rebound damping Turn adjuster clockwise (about 2 clicks) to in-
crease damping.
Low compression
dampingTurn adjuster clockwise (about 1 click) to increase
damping.
Spring Replace with stiff spring.
Heavy and dragging○○Rebound damping Turn adjuster counterclockwise (about 2 clicks) to
decrease damping.
Spring Replace with soft spring.
Poor road gripping○Rebound damping Turn adjuster counterclockwise (about 2 clicks) to
decrease damping.
Low compression
dampingTurn adjuster clockwise (about 1 clicks) to in-
crease damping.
High compression
dampingTurn adjuster clockwise (about 1/6 turn) to in-
crease damping.
Spring set length Set sunken length for 90–100 mm (3.5–3.9 in)
when one passenger is astride seat.
Spring Replace with soft spring.
Bottoming out○○High compression
dampingTurn adjuster clockwise (about 1/6 turn) to in-
crease damping.
Spring set length Set sunken length for 90–100 mm (3.5–3.9 in)
when one passenger in astride seat.
Spring Replace with stiff spring.
Bouncing○○Rebound damping Turn adjuster clockwise (about 2 clicks) to in-
crease damping.
Spring Replace with soft spring.
Stiff travel○○High compression
dampingTurn adjuster counterclockwise (about 1/6 turn) to
decrease damping.
Spring set length Set sunken length for 90–100 mm (3.5–3.9 in)
when one passenger is astride seat.
Spring Replace with soft spring.

5-4
CARBURETOR
CARBURETOR
REMOVING THE CARBURETOR
Order Part name Q'ty Remarks
Seat and fuel tank Refer to "REMOVING THE SEAT, FUEL
TANK AND SIDE COVERS" section in the
CHAPTER 3.
Rear shock absorber Refer to "REAR SHOCK ABSORBER" sec-
tion in the CHAPTER 6.
1Clamp 2
2 Throttle position sensor lead coupler 1
3 Throttle cable cover 1
4 Throttle cable 2
5 Clamp (air filter joint) 1 Loosen the screw (air filter joint).
6 Clamp (carburetor joint) 1 Loosen the screws (carburetor joint).
7 Hot starter plunger 1
8 Carburetor 1
9 Cylinder head breather pipe 1
10 Cylinder head breather hose 1 1
11 Cylinder head breather hose 2 1
12 Cylinder head breather hose 3 1

5-53
ENGINE REMOVAL
ENGINE REMOVAL
REMOVING THE ENGINE
Order Part name Q'ty Remarks
Hold the machine by placing the suitable stand
under the frame.Refer to "HANDLING NOTE".
Drain the engine oil.Refer to "CHANGING THE ENGINE OIL"
section in the CHAPTER 3.
Seat and fuel tank Refer to "REMOVING THE SEAT, FUEL
TANK AND SIDE COVERS" section in the
CHAPTER 3.
Radiator Refer to "RADIATOR" section.
Exhaust pipe and silencer Refer to "REMOVING THE EXHAUST PIPE
AND SILENCER" section in the CHAPTER 3.
Air cut-off valve assembly Refer to "AIR INDUCTION SYSTEM" section.
Clutch cable and guide Disconnect at the engine side.
Shift pedalRefer to "AC MAGNETO AND STARTER
CLUTCH" section.
Rear shock absorberRefer to "REAR SHOCK ABSORBER" sec-
tion in the CHAPTER 6.
Carburetor Refer to "CARBURETOR" section.
Cylinder head breather hose Refer to "CAMSHAFTS" section.
Oil hose and oil tank breather hose Refer to "OIL PUMP" section.