YAMAHA YFZ450R 2009 Service Manual

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8. Loosen the locknut.
9. Turn the adjusting nut in direction (a) to in-
crease the spring preload and thereby harden
the suspension, and in direction (b) to de-
crease the spring preload and thereby soften
the suspension.
TIP


A special wrench can be obtained at a Yamaha
dealer to make this adjustment.

The spring preload setting is determined by
measuring distance A, shown in the illustration.
The shorter distance A is, the higher the spring
preload; the longer distance A is, the lower the
spring preload. With each complete turn of the
adjusting nut, distance A is changed by 1.5 mm
1. Air filter case
2. Bolt
12 2

1. Spring preload adjusting nut
2. Locknut
3. Special wrench
123
(a)
(b)

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(0.06 in). 10. Tighten the locknut to the specified torque.
NOTICE

ECB00080
Always tighten the locknut against the adjust-
ing nut, and then tighten it to the specified
torque.
11. Place the air filter case in the original position,
install the bolts, and then tighten them to the
specified torque.
12. Connect the air intake duct to the air filter
case, and then tighten the clamp screw at the
air filter case side.
NOTICE
ECB00970
Make sure that the air intake duct is properly
connected to the air filter case, and that the
Spring preload setting:
Minimum (soft):
Distance A = 273.5 mm (10.77 in)
Standard:
Distance A = 265.0 mm (10.43 in)
Maximum (hard):
Distance A = 253.5 mm (9.98 in)
1. Distance A
1

Tightening torque:
Locknut:
30 Nm (3.0 m·kgf, 22 ft·lbf)
Tightening torque:
Bolt:
6.5 Nm (0.7 m·kgf, 4.7 ft·lbf)

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clamp screw is tightened securely.
13. Install the blow-by gas chamber by installing
the bolt, and then tighten it to the specified
torque.
14. Install the air filter case holding plate by install-
ing the bolts and collars.
15. Connect the coupler.
16. Connect the air intake duct to the throttle
body, and then tighten the clamp screw at the
throttle body side.
NOTICE

ECB00960
Make sure that the air intake duct is properly
connected to the throttle body, and that the
clamp screw is tightened securely.
17. Install the panel.
Rebound damping force
Turn the adjusting screw in direction (a) to increase
the rebound damping force and thereby harden
the damping, and in direction (b) to decrease therebound damping force and thereby soften the
damping.
Tightening torque:
Bolt:
6.5 Nm (0.7 m·kgf, 4.7 ft·lbf)

1. Position indicator marks
2. Rebound damping force adjusting screw
Rebound damping setting:
Minimum (soft):
20 turn(s) out from the fully turned in posi-
tion
Standard:
11 turn(s) out from the fully turned in posi-
tion
Maximum (hard):
1 turn(s) out from the fully turned in position
12
(a) (b)

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TIP

Make sure that the position indicator marks are
aligned when the shock absorber assembly is set
to the standard setting.
Compression damping force
Panels A and D need to be removed to make this
adjustment. (See page 8-8.)
Compression damping force (for fast compression
damping)To increase the compression damping force and
thereby harden the compression damping, turn the
adjusting bolt in direction (a). To decrease the
compression damping force and thereby soften
the compression damping, turn the adjusting bolt
in direction (b).

1. Compression damping force adjusting bolt (for fast com-
pression damping)
2. Position indicator marks
Compression damping setting (for fast com-
pression damping):
Minimum (soft):
2 turn(s) out from the fully turned in position
Standard:
1 turn(s) out from the fully turned in position
Maximum (hard):
Adjusting bolt fully turned in
1
2(a) (b)1

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Compression damping force (for slow compres-
sion damping)To increase the compression damping force and
thereby harden the compression damping, turn the
adjusting screw in direction (a). To decrease the
compression damping force and thereby soften
the compression damping, turn the adjusting
screw in direction (b).
NOTICE

ECB00090
Never turn an adjusting mechanism beyond
the minimum and maximum settings.TIP

Make sure that the position indicator marks are
aligned when the shock absorber assembly is
set to the standard setting(s).

Although the total number of clicks of a damping
force adjusting mechanism may not exactly
match the above specifications due to small dif-
ferences in production, the actual number of
clicks always represents the entire adjusting
range. To obtain a precise adjustment, it would
1. Compression damping force adjusting screw (for slow
compression damping)
(a)
(b) 1

Compression damping setting (for slow com-
pression damping):
Minimum (soft):
18 click(s) in direction (b)*
Standard:
8 click(s) in direction (b)*
Maximum (hard):
1 click(s) in direction (b)*
* With the adjusting screw fully turned in di-
rection (a)

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be advisable to check the number of clicks of
each damping force adjusting mechanism and
to modify the specifications as necessary.
WARNING

EWB00440
Suspension components become hot during
operation. Never touch the compression
damping force adjusting screw, the rebound
damping force adjusting screw or the oil reser-
voir with your bare hand or skin until suspen-
sion components have cooled.
EBU29400
Handlebar position
The handlebar can be adjusted to one of four posi-
tions to suit the rider’s preference. Have a Yamaha
dealer adjust the position of the handlebar.
1. Handlebar
1

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EBU19200
PRE-OPERATION CHECKS
EBU19223
Pre-operation check list
Before operating this ATV, be sure to check the items listed in the following table.
WARNING

EWB00480
Always inspect your ATV each time you use it to make sure it is in safe operating condition.
Always follow the inspection and maintenance procedures and schedules described in the Owner’s
Manual. Failure to inspect increases the possibility of an accident or equipment damage.
TIP

The maintenance of some items in the table has to be performed by a Yamaha dealer. Refer to the periodic
maintenance charts on page 8-3 to determine which service should be performed by a Yamaha dealer.
ITEM ROUTINE PAGE
Fuel


Check fuel level in fuel tank, and add recommended fuel if neces-
sary.

Check fuel line for leakage. Correct if necessary.4-9, 5-4
Engine oil

Check oil level in engine, and add recommended oil to specified
level if necessary.

Check ATV for oil leakage. Correct if necessary.5-4, 8-14
Coolant

Check coolant level in reservoir, and add recommended coolant to
specified level if necessary.

Check cooling system for leakage. Correct if necessary.5-4, 8-19

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Front brake

Check operation. If soft or spongy, have Yamaha dealer bleed
hydraulic system.

Check brake pads for wear, and replace if necessary.

Check brake fluid level in reservoir, and add recommended brake
fluid to specified level if necessary.

Check hydraulic system for leakage. Correct if necessary.5-4, 8-29, 8-30, 8-32
Rear brake

Check operation. If soft or spongy, have Yamaha dealer bleed
hydraulic system.

Check brake pads for wear, and replace if necessary.

Check brake fluid level in reservoir, and add recommended brake
fluid to specified level if necessary.

Check hydraulic system for leakage. Correct if necessary.5-4, 8-29, 8-30, 8-33
Clutch

Check operation, and correct if necessary.

Lubricate cable if necessary.

Check lever free play, and adjust if necessary.8-36
Throttle lever

Make sure that operation is smooth. Lubricate cable and lever hous-
ing if necessary.

Check cable free play, and adjust if necessary.5-5, 8-28
Control cables

Make sure that operation is smooth. Lubricate if necessary. 8-40
Drive chain

Check chain slack, and adjust if necessary.

Check chain condition. Lubricate if necessary.5-5, 8-37, 8-39
Wheels and tires

Check wheel condition, and replace if damaged.

Check tire condition and tread depth. Replace if necessary.

Check air pressure. Correct if necessary.5-5, 5-6, 5-7
Shift pedal

Make sure that operation is smooth.

Correct if necessary.8-41
Brake pedal

Make sure that operation is smooth. Lubricate pedal pivoting point if
necessary.8-41
Brake and clutch levers

Make sure that operation is smooth. Lubricate lever pivoting points
if necessary.8-40
Chassis fasteners

Make sure that all nuts, bolts and screws are properly tightened. 5-8
ITEM ROUTINE PAGE

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Instruments, lights and
switches

Check operation, and correct if necessary. 5-8
ITEM ROUTINE PAGE

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EBU19540
Fuel
Make sure that there is sufficient fuel in the tank.
(See page 4-9.)
WARNING

EWB00520

Do not overfill the fuel tank. Fuel expands
when it heats up. If the fuel tank is overfilled,
fuel could spill out due to heat from the en-
gine or the sun.

Be careful not to spill fuel, especially on the
engine or exhaust pipe which can cause a
fire and severe injury. Wipe up any spilled
fuel immediately.

Do not refuel right after the engine has been
running and is still very hot.

Be sure the fuel tank cap is closed securely.
EBU19560
Engine oil
Make sure that the engine oil is at the specified lev-
el. Add oil as necessary. (See page 8-14.)
EBU19630
Coolant
Make sure that the coolant is at the specified level.
Add coolant as necessary. (See page 8-19.)
TIP

The coolant level must be checked on a cold en-
gine since the level varies with engine tempera-
ture.
WARNING

EWB00510
Wait for the engine and radiator to cool before
removing the radiator cap. You could be
burned by hot fluid and steam blown out under
pressure. Always put a thick rag over the cap
when opening. Allow any remaining pressure
to escape before completely removing the cap.
EBU19710
Front and rear brakes
Brake lever and brake pedal

Check that there is no free play in the brake le-
ver. If there is free play, have a Yamaha dealer
check the brake system.

Check for correct brake pedal height. (See
page 8-33.) If the pedal height is incorrect, have
a Yamaha dealer adjust it.

Check the operation of the lever and pedal. They
should move smoothly and there should be a
firm feeling when the brakes are applied. If not,