2008 YAMAHA YFZ450 tires

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page 5-1 before riding for proper care of the ATV
and to ensure safety.
WARNING

EWB01430
Always inspect your ATV each time you use it
to make sure the ATV is in safe operating con-
dition. Always follow the inspection and main-
tenance procedures and schedules described
in the Owner’s Manual. Failure to inspect the
ATV before operating or failure to properly
maintain the ATV increases the possibility of
an accident or equipment damage.
WARNING

EWB01440
Always use the size and type tires specified in
the Owner’s Manual for this ATV on page 5-5.
Always maintain proper tire pressure as de-
scribed in the Owner’s Manual on page 5-6.
Use of improper tires on this ATV, or operation
of this ATV with improper or uneven tire pres-
sure, may cause loss of control, increasing
your risk of an accident.Do not operate at speeds too fast for your
skills or the conditions.WARNING
EWB01450
Always go at a speed that is proper for the ter-
rain, visibility and operating conditions, and
your experience. Operating this ATV at speeds
too fast for your skills or the conditions in-
creases your chances of losing control of the
ATV, which can result in an accident.
Speed limiter
For riders less experienced with this model, the
throttle lever housing is equipped with a speed lim-
iter. The speed limiter keeps the throttle from fully
opening, even when the throttle lever is pushed to
the maximum. Turning in the adjusting screw limits
the maximum engine power available and de-
creases the maximum speed of the ATV. Turning
in the adjusting screw decreases top speed, and
turning it out increases top speed. (See page 4-4.)

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these components.
With the engine idling, pull the clutch lever to dis-
engage the clutch and shift into 1st gear, and then
release the parking brake. Open the throttle grad-
ually, and at the same time, release the clutch le-
ver slowly. Once the ATV has attained adequate
speed, release the throttle lever and at the same
time, quickly pull in the clutch lever and shift into
2nd gear. Open the throttle part way and gradually
release the clutch. Use this same procedure as
you move into the higher gears. Be sure to coordi-
nate the use of the throttle and shift pedal properly.
If the throttle is applied too abruptly or if the throttle
is not released during shifting, or if the shift pedal
is not released before applying the throttle, the
front wheels may lift off the ground, resulting in a
loss of directional control. Avoid higher speeds un-
til you are thoroughly familiar with the operation of
your ATV.
WARNING

EWB01720
Always open the throttle gradually and release
the clutch lever slowly. Otherwise, the ATV
could wheelie which would increase the
chance of an accident.CAUTION:

ECB00230
Do not shift gears without releasing the throt-
tle. Damage to the engine or drive train may oc-
cur.
When slowing down or stopping, release the throt-
tle and apply the brakes smoothly and evenly. As
you slow down, shift to a lower gear. Be sure that
the engine has sufficiently slowed before engaging
a lower gear. Improper use of the brakes or shifting
can cause the tires to lose traction, reducing con-
trol and increasing the possibility of an accident.WARNING
EWB01560
Make sure the engine has sufficiently slowed
before shifting to a lower gear. Engaging a low-
er gear when the engine speed is too high
could cause the wheels to stop rotating.
TURNING YOUR ATV
To achieve maximum traction on unpaved surfac-
es, the two rear wheels are mounted solidly on one
axle and turn together at the same speed. There-
fore, unless the wheel on the inside of the turn is al-
lowed to slip or lose some traction, the ATV will
resist turning. A special turning technique must be

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in water deeper than that specified in your
Owner’s Manual. Remember that wet brakes
may have reduced stopping ability. Test your
brakes after leaving water. If necessary, apply
them several times to let friction dry out the lin-
ings. If the ATV is operated through deep or
fast flowing water, the tires may float, causing
loss of traction and loss of control, which
could lead to an accident.
Test your brakes after leaving the water. Do not
continue to ride your ATV without verifying that youhave regained proper braking ability.CAUTION:
ECB00240
After riding your ATV in water, be sure to drain
the trapped water by removing the check hose
at the bottom of the air filter case. Wash the
ATV in fresh water if it has been operated in
salt water or muddy conditions.

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EBU21864
General maintenance and lubrication chart
NO. ITEMCHECK OR MAINTENANCE
JOBINITIAL EVERY
Whichev-
er comes
firstmonth 1 3 6 6 12
km
(mi)320
(200)1300
(800)2500
(1600)2500
(1600)5000
(3200)
hours 20 80 160 160 3201 Air filter element


Clean and replace if necessary.Every 20–40 hours (more often in wet or
dusty areas)
2
*
Clutch

Check operation and adjust if necessary.
√ √√√
3
*
Front brake


Check operation and correct if necessary.

Check fluid level and ATV for fluid leakage, and
correct if necessary.
√√√√√

Replace brake pads. Whenever worn to the limit
4
*
Rear brake

Check operation and correct if necessary.

Check fluid level and ATV for fluid leakage, and
correct if necessary.
√√√√√

Replace brake pads. Whenever worn to the limit
5
*
Brake hoses

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

Replace. Every 4 years
6
*
Parking brake

Check operation and adjust if necessary.
√√√√√
7
*
Wheels


Check runout and for damage, and replace if nec-
essary.
√ √√√
8
*
Tires


Check tread depth and for damage, and replace if
necessary.

Check air pressure and balance, and correct if
necessary.
√ √√√
9
*
Wheel hub bearings


Check for looseness or damage, and replace if
necessary.
√ √√√

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with oil.)
e. Remove the spark plug cap from the spark
plug, and then install the spark plug and
the spark plug cap.
6. Lubricate all control cables and the pivoting
points of all levers and pedals.
7. Check and, if necessary, correct the tire air
pressure, and then block up the ATV so that
all of its wheels are off the ground. Alternative-
ly, turn the wheels a little every month in order
to prevent the tires from becoming degraded
in one spot.
8. Cover the muffler outlet with a plastic bag to
prevent moisture from entering it.
9. Remove the battery and fully charge it. Store
it in a cool, dry place and charge it once a
month. Do not store the battery in an exces-
sively cold or warm place [less than 0 °C (30
°F) or more than 30 °C (90 °F)]. For more in-
formation on storing the battery, see page
8-45.
NOTE:

Make any necessary repairs before storing the
ATV.

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5th:
21/20 (1.050)
Chassis:
Frame type:
Steel tube frame
Caster angle:
5.0 °
Trail:
21.0 mm (0.83 in)
Front tire:
Type:
Tubeless
Size:
AT21 x 7-10
Manufacturer/model:
DUNLOP/KT341 Radial
Rear tire:
Type:
Tubeless
Size:
AT20 x 10-9
Manufacturer/model:
DUNLOP/KT355A Radial
Loading:
Maximum loading limit:
100.0 kg (220 lb)
(Total weight of rider, cargo, accessories, and tongue)
Tire air pressure (measured on cold tires):
Recommended:
Front:
27.5 kPa (4.0 psi) (0.275 kgf/cm
2

)Rear:
30.0 kPa (4.4 psi) (0.300 kgf/cm
2

)
Minimum:
Front:
24.5 kPa (3.5 psi) (0.245 kgf/cm
2

)
Rear:
27.0 kPa (3.9 psi) (0.270 kgf/cm
2

)
Maximum:
Front:
30.5 kPa (4.4 psi) (0.305 kgf/cm
2

)
Rear:
33.0 kPa (4.8 psi) (0.330 kgf/cm
2

)
Front wheel:
Wheel type:
Panel wheel
Rim size:
10 x 5.5AT
Rear wheel:
Wheel type:
Panel wheel
Rim size:
9 x 8.5AT
Front brake:
Type:
Dual disc brake
Operation:
Right hand operation
Recommended fluid:
DOT 4

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