2008 YAMAHA YFZ450 ABS

EBU17420
TABLE OF CONTENTS
SAFETY INFORMATION .............................. 1-1
LOCATION OF THE WARNING AND
SPECIFICATION LABELS ............................ 2-1
DESCRIPTION .............................................. 3-1
Left view ..................................................... 3-1
Right view................................................... 3-1
Controls and instruments ........................... 3-2
INSTRUMENT AND CONTROL
FUNCTIONS .................................................. 4-1
Main switch ............................................... 4-1
Indicator light and warning light ................. 4-1
Handlebar switches ................................... 4-2
Throttle lever ............................................. 4-3
Speed limiter ............................................. 4-4
Clutch lever ............................................... 4-5
Brake lever ................................................ 4-5
Brake pedal ............................................... 4-5
Parking brake lever ................................... 4-6
Shift pedal ................................................. 4-7
Fuel tank cap ............................................. 4-7
Fuel ........................................................... 4-8
Fuel cock ................................................... 4-9Starter (choke) “ ” .................................. 4-10
Seat ......................................................... 4-11
Adjusting the front shock absorber
assemblies ............................................. 4-12
Adjusting the rear shock absorber
assembly ................................................ 4-17
PRE-OPERATION CHECKS ..........................5-1
Pre-operation check list ............................. 5-1
Fuel ............................................................ 5-4
Engine oil ................................................... 5-4
Coolant ...................................................... 5-4
Front and rear brakes ................................ 5-4
Throttle lever .............................................. 5-5
Drive chain ................................................. 5-5
Tires ........................................................... 5-5
Measuring the tire pressure ....................... 5-6
Tire wear limit ............................................ 5-7
Chassis fasteners ...................................... 5-8
Instruments, lights and switches ................ 5-8
OPERATION...................................................6-1
Starting a cold engine ................................ 6-1
Starting a warm engine .............................. 6-3
Shifting ....................................................... 6-3
Engine break-in .......................................... 6-5

4-12
1
2
34
5
6
7
8
9
10
11

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
1
2

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).
NOTE:
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
CAUTION:
ECB00090
Never turn an adjusting mechanism beyond
the minimum and maximum settings.
NOTE:

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.

4-21
1
2
34
5
6
7
8
9
10
11
NOTE:

Make sure that the position indicator marks are
aligned when the shock absorber assembly is set
to the standard setting.
Compression damping force
Compression damping force (for fast compressiondamping)1. Remove the seat. (See page 4-11.)
2. 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).

1. Position indicator marks
2. Rebound damping force adjusting screw
Rebound damping setting:
Minimum (soft):
3 turn(s) out from the fully turned in position
Standard:
1 1/2 turn(s) out from the fully turned in po-
sition
Maximum (hard):
Fully turned in
21
(b)
(a)

4-22
1
2
34
5
6
7
8
9
10
11

3. Install the seat.NOTE:

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. Remove the seat. (See page 4-11.)
2. 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
Compression damping setting (for fast com-
pression damping):
Minimum (soft):
3 turn(s) out from the fully turned in position
Standard:
2 turn(s) out from the fully turned in position
Maximum (hard):
Fully turned in
(b)(a)
1
2
1

8-6
1
2
3
4
5
6
78
9
10
11

10
*
Swingarm pivots

Check operation and for excessive play, and
replace bearings if necessary.

Lubricate with molybdenum disulfide grease.
√√√
11
*
Upper and lower
arm pivots


Lubricate with lithium-soap-based grease.
√√√
12 Drive chain

Check chain slack and adjust if necessary.

Check rear wheel alignment and correct if necess-
sary.

Clean and lubricate.
√√√√√
13
*
Drive chain rollers


Check for wear and replace if necessary.
√√√
14
*
Chassis fasteners


Make sure that all nuts, bolts, and screws are
properly tightened.
√√√√√
15
*
Shock absorber
assemblies


Check operation and correct if necessary.

Check for oil leakage and replace if necessary.
√√√
16
*
Rear suspension
relay arm and con-
necting arm pivot-
ing points


Check operation and correct if necessary.

Lubricate with lithium-soap-based grease.
√√√√
17
*
Steering shaft


Lubricate with lithium-soap-based grease.
√√√
18
*
Steering system


Check operation and repair or replace if damaged.

Check toe-in and adjust if necessary.
√√√√√
19
*
Engine mount


Check for cracks or other damage, and replace if
necessary.
√√√
NO. ITEMCHECK OR MAINTENANCE
JOBINITIAL EVERY
Whichev-
er comes
firstmonth136612
km
(mi)320
(200)1300
(800)2500
(1600)2500
(1600)5000
(3200)
hours 20 80 160 160 320