2008 YAMAHA YFZ450 maintenance

8-39
1
2
3
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78
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10
11

EBU24740
Brake light switches
The operation of the brake light switches must be
checked and, if necessary, adjusted at the inter-
vals specified in the periodic maintenance and lu-
brication chart.
The brake light switch for the brake pedal can be
adjusted as follows, but the other brake light
switches should be adjusted by a Yamaha dealer.
NOTE:

The brake light switch is properly adjusted when
the brake light comes on just before braking takes
effect.
Turn the adjusting nut while holding the brake light
switch in place. To make the brake light come on
earlier, turn the adjusting nut in direction (a). To
make the brake light come on later, turn the adjust-
ing nut in direction (b).
EBU24820
Adjusting the clutch lever free play
The clutch lever free play must be checked and, if
necessary, adjusted at the intervals specified in
the periodic maintenance and lubrication chart.
The clutch lever free play should measure 8.0–
13.0 mm (0.31–0.51 in) as shown. If the free play
is incorrect, adjust it as follows.
1. Brake light switch
2. Brake light switch adjusting nut
(a)
(b)1
2

8-41
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78
9
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11

EBU24880
Lubricating the drive chain
The drive chain must be cleaned and lubricated at
the intervals specified in the periodic maintenance
and lubrication chart, otherwise it will quickly wear
out, especially when riding in dusty or wet areas.
Service the drive chain as follows.
CAUTION:

ECB00560
The drive chain must be lubricated after wash-
ing the ATV or riding in the rain.
1. Clean the drive chain with kerosene and asmall soft brush.
CAUTION:

ECB00570
To prevent damaging the O-rings, do not clean
the drive chain with steam cleaners, high-pres-
sure washers or inappropriate solvents.
2. Wipe the drive chain dry.
3. Thoroughly lubricate the drive chain with a
special O-ring chain lubricant.
CAUTION:

ECB00580
Do not use engine oil or any other lubricants
for the drive chain, as they may contain sub-
stances that could damage the O-rings.
EBU24900
Checking and lubricating the cables
The operation and the condition of all control ca-
bles should be checked before each ride, and the
cables and cable ends should be lubricated if nec-
essary. If a cable is damaged or does not move
smoothly, have a Yamaha dealer check or replace
it.
1. O-rings
1

Recommended lubricant:
Engine oil

8-43
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78
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11

EBU24931
Checking and lubricating the brake and
shift pedals
The operation of the brake and shift pedals should
be checked before each ride, and the pedal pivots
should be lubricated if necessary.
Brake pedal
EBU24962
Checking the wheel hub bearings
The front and rear wheel hub bearings must be
checked at the intervals specified in the periodic
maintenance and lubrication chart. If there is play
in a wheel hub or if a wheel does not turn smoothly,
have a Yamaha dealer check the wheel hub bear-
ings.
EBU24992
Lubricating the swingarm pivots
The swingarm pivots must be lubricated at the in-
tervals specified in the periodic maintenance and
lubrication chart. Recommended lubricants:
Brake pedal:
Silicone grease
Shift pedal:
Lithium-soap-based grease (all-purpose
grease)
Recommended lubricant:
Lithium-soap-based grease

8-45
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78
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11
Right side

EBU25222
Battery
This model is equipped with a sealed-type (MF)
battery, which does not require any maintenance.
There is no need to check the electrolyte or to add
distilled water. Check and, if necessary, tighten the
battery lead connections.
CAUTION:

ECB00620
Never attempt to remove the battery cell seals,
as this would permanently damage the battery.WARNING
EWB02160
Battery electrolyte is poisonous and danger-
ous, as it contains sulfuric acid, which can
cause severe burns. Avoid contact with skin,
eyes or clothing. Always shield your eyes
when working near batteries.
Antidote:
EXTERNAL: Flush with water.
INTERNAL: Drink large quantities of water or
milk. Follow with milk of magnesia, beaten egg
or vegetable oil. Call a physician immediately.
EYES: Flush with water for 15 minutes and get
prompt medical attention.
Batteries produce explosive gases. Keep
sparks, flame, cigarettes or other sources of ig-
nition away. Ventilate when charging or using
in an enclosed space.
KEEP OUT OF REACH OF CHILDREN.
To charge the battery
Have a Yamaha dealer charge the battery as soon
as possible if it seems to have discharged. Keep in
mind that the battery tends to discharge more
quickly if the ATV is equipped with optional electri-
cal accessories.
1. Upper grease nipple
2. Lower grease nipple
2 1

L
Label locations ................................................................2-1
Light switch .....................................................................4-3
M
Main switch .....................................................................4-1
Maintenance and lubrication chart ..................................8-5
Maintenance chart, emission control system ..................8-3
Model label....................................................................11-2
N
Neutral indicator light ......................................................4-1
O
Owner’s manual and tool kit............................................8-1
P
Panel, removing and installing ........................................8-9
Parking ............................................................................6-5
Parking brake free play, adjusting.................................8-37
Parking brake lever .........................................................4-6
Parking on a slope ..........................................................6-6
Part locations ..................................................................3-1
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 ...............4-17
Spark arrester, cleaning ................................................8-28
Spark plug, checking.....................................................8-10Specifications ............................................................... 10-1
Speed limiter .................................................................. 4-4
Starter (choke) ............................................................. 4-10
Start switch .................................................................... 4-3
Storage .......................................................................... 9-2
Suspension, lubricating the upper and lower arm
pivots ......................................................................... 8-44
Swingarm pivots, lubricating ........................................ 8-43
T
Tail/brake light bulb, replacing ..................................... 8-50
Throttle cable free play, adjusting ................................ 8-30
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 ........................................................... 8-31
Vehicle identification number ....................................... 11-1
W
Wheel hub bearings, checking ..................................... 8-43
Wheel, installing ........................................................... 8-50
Wheel, removing .......................................................... 8-50