suspension YAMAHA YFZ450 2007 Owners Manual

4-13
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8
9
10
11

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

4-16
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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
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.
EBU19120
Adjusting the rear shock absorber
assembly
The spring preload, rebound damping and com-
pression damping forces of the rear shock absorb-
er assembly can be adjusted to suit the rider’s Compression damping setting:
Minimum (soft):
20 click(s) in direction (b)*
Standard:
11 click(s) in direction (b)*
Maximum (hard):
1 click(s) in direction (b)*
* With the adjusting screw fully turned in di-
rection (a)

4-18
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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.
1. Hose
1

1. Bolt
2. Air filter case
2 1

4-21
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to the standard setting.
Compression damping force
1. Remove the seat. (See page 4-11.)
2. Turn the adjusting screw in direction (a) to in-
crease the compression damping force and
thereby harden the damping, and in direction
(b) to decrease the compression damping
force and thereby soften the damping.CAUTION:
ECB00090
Never turn an adjusting mechanism beyond
the minimum and maximum settings.
NOTE:

Make sure that the position indicator marks are
aligned when the shock absorber assembly is set
to the standard setting.
3. Install the seat.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-
1. Compression damping force adjusting screw
2. Position indicator marks
(a)
(b)1
2

Compression damping setting:
Minimum (soft):
Adjusting screw fully turned out
Standard:
Adjusting screw 1 3/4 turns out from the
fully turned in position
Maximum (hard):
Adjusting screw fully turned in

8-5
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9
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15 Drive chain

Check chain slack and adjust if necessary.

Check rear wheel alignment and correct if necess-
sary.

Clean and lubricate.
√√√√√
16
*
Drive chain rollers


Check for wear and replace if necessary.
√√√
17
*
Chassis fasteners


Make sure that all nuts, bolts, and screws are
properly tightened.
√√√√√
18
*
Shock absorber
assemblies


Check operation and correct if necessary.

Check for oil leakage and replace if necessary.
√√√
19
*
Rear suspension
relay arm and con-
necting arm pivot-
ing points


Check operation and correct if necessary.

Lubricate with lithium-soap-based grease.
√√√√
20
*
Steering shaft


Lubricate with lithium-soap-based grease.
√√√
21
*
Steering system


Check operation and repair or replace if damaged.

Check toe-in and adjust if necessary.
√√√√√
22
*
Engine mount


Check for cracks or other damage, and replace if
necessary.
√√√
23
*
Carburetor


Check starter (choke) operation and correct if nec-
essary.

Check engine idling speed and adjust if neces-
sary.
√√√√
24
*
Crankcase breather
system


Check breather hose for cracks or other damage,
and replace if necessary.
√√√
NO. ITEMCHECK OR MAINTENANCE
JOBINITIAL EVERY
Whichev-
er comes
firstmonth136612
km
(mi)320
(200)1200
(750)2400
(1500)2400
(1500)4800
(3000)
hours 20 75 150 150 300

10-4
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3
4
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910
11
Rear brake:

Type:
Single disc brake
Operation:
Right foot operation
Recommended fluid:
DOT 4
Front suspension:
Type:
Double wishbone
Spring/shock absorber type:
Coil spring/gas-oil damper
Wheel travel:
230 mm (9.1 in)
Rear suspension:
Type:
Swingarm (link suspension)
Spring/shock absorber type:
Coil spring/gas-oil damper
Wheel travel:
270 mm (10.6 in)
Electrical system:
Ignition system:
DC. CDI
Charging system:
AC magneto
Battery:
Model:
GT7B-4
Voltage, capacity:
12 V, 6.5 Ah
Headlight:
Bulb type:
Krypton bulb
Bulb voltage, wattage x quantity:
Headlight:
12 V, 30.0/30.0 W
×
2
Tail/brake light:
12 V, 0.5/3.9 W
×
1
Neutral indicator light:
12 V, 1.7 W
×
1
Coolant temperature warning light:
12 V, 1.7 W
×
1

Fuses:
Main fuse:
15.0 A

K
Key identification number ............................................. 11-1
L
Label locations ............................................................... 2-1
Light switch .................................................................... 4-3
M
Main switch .................................................................... 4-1
Model label ................................................................... 11-2
N
Neutral indicator light ..................................................... 4-2
O
Owner’s manual and tool kit ........................................... 8-1
P
Panel, removing and installing ....................................... 8-8
Parking ........................................................................... 6-5
Parking brake free play, adjusting ................................ 8-36
Parking brake lever ........................................................ 4-6
Parking on a slope ......................................................... 6-6
Part locations ................................................................. 3-1
Periodic maintenance and lubrication chart ................... 8-3
Pre-operation check list.................................................. 5-1
R
Riding your ATV ............................................................. 7-1
S
Safety information .......................................................... 1-1
Seat .............................................................................. 4-11
Shifting ........................................................................... 6-3
Shift pedal ...................................................................... 4-7
Shock absorber assemblies, adjusting the front .......... 4-12
Shock absorber assembly, adjusting the rear .............. 4-16
Spark arrester, cleaning ............................................... 8-26Spark plug, checking ...................................................... 8-9
Specifications ............................................................... 10-1
Speed limiter .................................................................. 4-4
Starter (choke) ............................................................. 4-11
Start switch..................................................................... 4-3
Storage........................................................................... 9-2
Suspension, lubricating the upper and lower arm
pivots.......................................................................... 8-44
Swingarm pivots, lubricating ........................................ 8-44
T
Tail/brake light bulb, replacing ..................................... 8-50
Throttle cable free play, adjusting ................................ 8-29
Throttle lever .......................................................... 4-3
,
5-5
Tire pressure, measuring ............................................... 5-6
Tires ............................................................................... 5-5
Tire wear limit ................................................................. 5-7
Troubleshooting ........................................................... 8-51
Troubleshooting charts................................................. 8-52
V
Valve clearance............................................................ 8-30
Vehicle identification number ....................................... 11-1
W
Wheel bearings, checking ............................................ 8-43
Wheel, installing ........................................................... 8-50
Wheel, removing .......................................................... 8-50