2008 YAMAHA YFZ450 lock

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fore riding the ATV or consult a Yamaha dealer.
EBU18321
Speed limiter
Your ATV was delivered with an adjustable speed
limiter. The speed limiter keeps the throttle from
fully opening, even when the throttle lever is
pushed to the maximum.
1. Loosen the locknut.
2. To increase the maximum engine power avail-
able and the maximum speed of the ATV, turn
the adjusting screw in direction (a). To de-
crease the maximum engine power available
and the maximum speed of the ATV, turn the
adjusting screw in direction (b).
3. Tighten the locknut.
WARNING
EWB00240
Improper adjustment of the speed limiter and
throttle could cause throttle cable damage or
improper throttle operation. You could lose
control, have an accident or be injured. Do not
turn the adjusting screw out more than 12 mm
(0.47 in) or the throttle cable could be dam-
aged. Always make sure the throttle lever free
play is adjusted to 2.0–4.0 mm (0.08–0.16 in).
1. Locknut
2. Adjusting screw
3. No more than 12 mm (0.47 in)
3
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(a)
(b)

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(See page 8-30.)
EBU18382
Clutch lever
The clutch lever is located on the left handlebar
and the ignition circuit cut-off system is incorporat-
ed in the clutch lever holder. To disengage the
clutch, pull the clutch lever toward the handlebar
grip. To engage the clutch, release the clutch lever.
The clutch lever should be pulled rapidly and re-
leased slowly for smooth clutch operation. (See
page 6-1 for a description of the ignition circuit cut-
off system.)
EBU18411
Brake lever
The brake lever is located at the right handlebar
grip. To apply the front brake, pull the brake lever
toward the handlebar grip.
EBU18432
Brake pedal
The brake pedal is located on the right side of the
ATV. To apply the rear brake, push down on the
brake pedal.
1. Clutch lever
1. Brake lever
2. Locknut
3. Brake lever position adjusting bolt
4. Distance between brake lever and handlebar grip
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EBU18520
Parking brake lever
Use the parking brake before starting the engine or
parking the ATV, especially on a slope. To apply
the parking brake, move the parking brake lever in
direction (a). To release the parking brake, move
the parking brake lever in direction (b).
1. Brake pedal
1

1. Parking brake lever (locked position)
1. Parking brake lever (unlocked position)

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WARNING

EWB00220

Always set the parking brake before starting
the engine. The ATV could start moving un-
expectedly if the parking brake is not ap-
plied. This could cause loss of control or a
collision.

Always be sure you have released the park-
ing brake before you begin to ride. The brake
could overheat if you ride the ATV without re-
leasing the parking brake. You could lose
braking performance which could cause an
accident. You could also wear out the brakes
prematurely.
EBU18530
Shift pedal
This ATV is equipped with a constant-mesh 5-
speed transmission. The shift pedal is located on
the left side of the engine and is used in combina-
tion with the clutch when shifting.
EBU18720
Fuel tank cap
Remove the fuel tank cap by turning it counter-
clockwise.
1. Shift pedal
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the starter (choke).
Move the starter (choke) in direction (b) to turn off
the starter (choke).
See the “Starting a cold engine” section on page
6-1 for proper operation.
EBU18890
Seat
To remove the seat
Insert your hand between the rear of the seat and
the rear fender, pull the seat lock lever upward and
pull up the seat at the rear.
To install the seat
Insert the projections on the front of the seat into
the seat holders and push down on the seat at the
rear.NOTE:

Make sure that the seat is securely fitted.
1. Starter (choke) “ ”
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(a)(b)

1. Seat lock lever1

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EBU27903
Adjusting the front shock absorber
assemblies
These shock absorber assemblies are equipped
with a spring preload adjusting nut, a rebound
damping force adjusting screw, with a compres-
sion damping force adjusting bolt (for fast com-
pression damping), and a compression damping
force adjusting screw (for slow compression damp-
ing).
WARNING
EWB00410
These shock absorber assemblies contain
highly pressurized nitrogen gas. Read and un-
derstand the following information before han-
dling the shock absorber assemblies.

Do not tamper with or attempt to open the
cylinder assemblies.

Do not subject the shock absorber assem-
blies to an open flame or other high heat
source. This may cause the unit to explode
due to excessive gas pressure.

Do not deform or damage the cylinders in
any way. Cylinder damage will result in poor
damping performance.

Do not dispose of a damaged or worn out
shock absorber assembly yourself. Take the
shock absorber assembly to a Yamaha deal-
er for any service.
Spring preload
1. Loosen the locknut.
2. 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
1. Projection
2. Seat holder
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2

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the suspension.
NOTE:


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

Spring preload setting:
Minimum (hard):
Distance A = 246.5 mm (9.70 in)
Standard:
Distance A = 255.0 mm (10.04 in)
Maximum (soft):
Distance A = 261.5 mm (10.30 in)
1. Distance A
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3. Tighten the locknut to the specified torque.
CAUTION:

ECB00080
Always tighten the locknut against the adjust-
ing nut, and then tighten it to the specified
torque.
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 the
rebound damping force and thereby soften the
damping.Tightening torque:
Locknut:
30 Nm (3.0 m·kgf, 22 ft·lbf)
1. Rebound damping force adjusting screw
Rebound damping setting:
Minimum (soft):
20 click(s) in direction (b)*
Standard:
10 click(s) in direction (b)*
Maximum (hard):
1 click(s) in direction (b)*
* With the adjusting screw fully turned in di-
rection (a)
(b)
(a)
1