2009 YAMAHA YFZ450 Owners Manual

4-13
1
2
34
5
6
7
8
9
10
11

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

4-14
1
2
34
5
6
7
8
9
10
11

3. 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.
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

4-15
1
2
34
5
6
7
8
9
10
11

Compression damping force
Compression damping force (for fast compression
damping)1. To increase the compression damping force
and thereby harden the compression damp-
ing, 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).
TIP

Make sure that the position indicator marks are
aligned when the shock absorber assembly is set
to the standard setting.
Compression damping force (for slow compres-
sion damping)1. To increase the compression damping force
and thereby harden the compression damp-
ing, 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).

1. Compression damping force adjusting bolt (for fast com-
pression damping)
2. Position indicator marks
(a) 11
2
(b)

Compression damping setting (for fast com-
pression damping):
Minimum (soft):
3 turn(s) out from the fully turned in position
Standard:
1 turn(s) out from the fully turned in position
Maximum (hard):
Fully turned in

4-16
1
2
34
5
6
7
8
9
10
11
NOTICE

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

Although the total number of clicks of a damping
force adjusting mechanism may not exactly match
the above specifications due to small differences in
production, the actual number of clicks always rep-
resents the entire adjusting range. To obtain a pre-
cise adjustment, it would be advisable to check the
number of clicks of each damping force adjusting
mechanism and to modify the specifications as
necessary.
WARNING

EWB00420

Suspension components become hot during
operation. Never touch the compression
damping force adjusting screw, the rebound
damping force adjusting screw or the oil res-
ervoir with your bare hand or skin until sus-
pension components have cooled.

Always adjust the shock absorber assem-
blies on the left and right side to the same
1. Compression damping force adjusting screw (for slow
compression damping)
Compression damping setting (for slow com-
pression damping):
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

4-17
1
2
34
5
6
7
8
9
10
11

setting.
WARNING

EWB00400
Always adjust the shock absorber assemblies
on the left and right side to the same setting.
Uneven adjustment can cause poor handling
and loss of stability, which could lead to an ac-
cident.
EBU27923
Adjusting the rear shock absorber
assembly
This shock absorber assembly is equipped with a
spring preload adjusting nut, a rebound damping
force adjusting screw, with a compression damp-
ing force adjusting bolt (for fast compression
damping), and a compression damping force ad-
justing screw (for slow compression damping).
WARNING

EWB00430
This shock absorber assembly contains highly
pressurized nitrogen gas. Read and under-
stand the following information before han-
dling the shock absorber assembly.

Do not tamper with or attempt to open thecylinder assembly.

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

Do not deform or damage the cylinder 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. Remove the seat. (See page 4-11.)
2. Loosen the clamp screw at the carburetor
side, and then disconnect the air intake duct.

4-18
1
2
34
5
6
7
8
9
10
11

3. Disconnect the hose, and then remove the air
filter case by removing the bolts.
1. Clamp screw
1

1. Hose
1

4-19
1
2
34
5
6
7
8
9
10
11

4. Loosen the locknut.
5. 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. Bolt
2. Air filter case
2 1

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

4-20
1
2
34
5
6
7
8
9
10
11

(0.06 in). 6. 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.
7. Place the air filter case in the original position,
connect the air intake duct, and then tighten
the clamp screw at the carburetor side.
8. Install the bolts, and then connect the hose.
9. Install the seat.
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. Spring preload setting:
Minimum (hard):
Distance A = 250.0 mm (9.84 in)
Standard:
Distance A = 257.0 mm (10.12 in)
Maximum (soft):
Distance A = 265.0 mm (10.43 in)

1. Distance A
1

Tightening torque:
Locknut:
44 Nm (4.4 m·kgf, 33 ft·lbf)