brake YAMAHA YFZ450 2008 User Guide

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Rear brake

Check operation. If soft or spongy, have Yamaha dealer bleed
hydraulic system.

Check brake pads for wear, and replace if necessary.

Check brake fluid level in reservoir, and add recommended brake
fluid to specified level if necessary.

Check hydraulic system for leakage. Correct if necessary.5-4, 8-31, 8-32, 8-36
Clutch

Check operation, and correct if necessary.

Lubricate cable if necessary.

Check lever free play, and adjust if necessary.8-39
Throttle lever

Make sure that operation is smooth. Lubricate cable and lever hous-
ing if necessary.

Check cable free play, and adjust if necessary.5-5, 8-30
Control cables

Make sure that operation is smooth. Lubricate if necessary. 8-41
Drive chain

Check chain slack, and adjust if necessary.

Check chain condition. Lubricate if necessary.5-5, , 8-41
Wheels and tires

Check wheel condition, and replace if damaged.

Check tire condition and tread depth. Replace if necessary.

Check air pressure. Correct if necessary.5-5, 5-6, 5-7
Brake and shift pedals

Make sure that operation is smooth. Lubricate pedal pivoting points
if necessary.8-43
Brake and clutch levers

Make sure that operation is smooth. Lubricate lever pivoting points
if necessary.8-42
Chassis fasteners

Make sure that all nuts, bolts and screws are properly tightened. 5-8
Instruments, lights and
switches

Check operation, and correct if necessary. 5-8
ITEM ROUTINE PAGE

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EBU19540
Fuel
Make sure that there is sufficient fuel in the tank.
(See page 4-8.)
WARNING

EWB00520

Do not overfill the fuel tank. Fuel expands
when it heats up. If the fuel tank is overfilled,
fuel could spill out due to heat from the en-
gine or the sun.

Be careful not to spill fuel, especially on the
engine or exhaust pipe which can cause a
fire and severe injury. Wipe up any spilled
fuel immediately.

Do not refuel right after the engine has been
running and is still very hot.

Be sure the fuel tank cap is closed securely.
EBU19560
Engine oil
Make sure that the engine oil is at the specified lev-
el. Add oil as necessary.
EBU19630
Coolant
Make sure that the coolant is at the specified level.
Add coolant as necessary. (See page 8-20.)
NOTE:

The coolant level must be checked on a cold en-
gine since the level varies with engine tempera-
ture.
WARNING

EWB00510
Wait for the engine and radiator to cool before
removing the radiator cap. You could be
burned by hot fluid and steam blown out under
pressure. Always put a thick rag over the cap
when opening. Allow any remaining pressure
to escape before completely removing the cap.
EBU19710
Front and rear brakes
Brake lever and brake pedal

Check that there is no free play in the brake le-
ver. If there is free play, have a Yamaha dealer
check the brake system.

Check for correct brake pedal height. (See
page 8-36.) If the pedal height is incorrect, have
a Yamaha dealer adjust it.

Check the operation of the lever and pedal. They
should move smoothly and there should be a
firm feeling when the brakes are applied. If not,

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have a Yamaha dealer check the brake system.
Brake fluid level
Check the brake fluid level. Add fluid if necessary.
(See page 8-32.)
Brake fluid leakage
Check to see if any brake fluid is leaking out of the
pipe joints or brake fluid reservoirs. Apply the
brakes firmly for one minute. If there is any leak-
age, have a Yamaha dealer check the brake sys-
tem.
Brake operation
Test the brakes at slow speed after starting out to
make sure they are working properly. If the brakes
do not provide proper braking performance, check
the brake pads for wear. (See page 8-31.)
WARNING

EWB00580
Always check the brakes at the start of every
ride. Do not ride the ATV if you find any prob-
lem with the brakes or you could lose braking
ability, which could lead to an accident. If aproblem cannot be corrected by the adjust-
ment procedures provided in this manual, have
a Yamaha dealer check for the cause.
EBU19761
Throttle lever
Check the operation of the throttle lever. It must
open smoothly and spring back to the idle position
when released. Have a Yamaha dealer correct if
necessary.
EBU19770
Drive chain
Check the condition of the drive chain and check
the drive chain slack. Lubricate and adjust the
drive chain as necessary.
EBU19791
Tires
WARNING

EWB00601
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 accident.
Pay attention to the following.

The tires listed below have been approved
Recommended brake fluid:
DOT 4

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EBU19880
OPERATION
EBU19900
Read the Owner’s Manual carefully before riding
the ATV.
WARNING

EWB00630
Read the Owner’s Manual carefully to become
familiar with all controls in order to help pre-
vent any loss of control, which could cause an
accident or injury. If there is a control or func-
tion you do not understand, ask your Yamaha
dealer.
EBU20101
Starting a cold engine
WARNING

EWB00640
Always make sure all control cables work
smoothly before you begin riding in cold
weather. If the control cables are frozen or do
not work smoothly, you could be unable to
control the ATV, which could lead to an acci-
dent or collision.
CAUTION:

ECB00150
See the “Engine break-in” section on page 6-5
prior to operating the engine for the first time.
1. Set the parking brake.
2. Turn the fuel cock to “ON”.
3. Turn the main switch to “ON” and the engine
stop switch to “RUN”.
4. Shift the transmission into neutral. The neutral
indicator light should come on. If the indicator
light does not come on, have a Yamaha deal-
er check the electrical circuit.
NOTE:

This model is equipped with an ignition circuit cut-
off system. The engine can be started under the
following conditions.

The transmission is in neutral.

The clutch is disengaged with the transmission
in gear. However, it is recommended to shift into
neutral before starting the engine.
5. Use the starter (choke) in reference to the fig-
ure:

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CAUTION:

ECB00200
Always close the throttle before shifting gears,
otherwise damage to the engine and drive train
may result.
2. Pull the clutch lever to disengage the clutch.
3. Shift into first gear.
4. Open the throttle gradually and at the same
time, release the clutch lever slowly.
5. Once the ATV has attained adequate speed,
release the throttle, and at the same time,
quickly pull in the clutch lever.
6. Shift the transmission into second gear.
(Make sure not to shift the transmission into
neutral)
7. Open the throttle part way and gradually re-
lease the clutch lever.
8. Follow the same procedure when shifting to
the next higher gear.
WARNING

EWB00730
Opening the throttle abruptly or releasing the
clutch lever too quickly could make the ATV
wheelie, which would increase the chance of
an accident, including an overturn.
EBU20650
To decelerate
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
EWB00710
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 make the wheels stop rotating and lose
traction. This could cause loss of control, an
accident and injury. It could also cause engine
or drive train damage.
CAUTION:

ECB00180

Even with the transmission in the neutral po-
sition, do not coast for long periods of time
with the engine off, and do not tow the ATV
for long distances. The transmission is prop-
erly lubricated only when the engine is run-
ning. Inadequate lubrication may damage

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the transmission.

Always use the clutch when changing gears.
The engine, transmission and drive train are
not designed to withstand the shock of
forced shifting and can be damaged by shift-
ing without using the clutch.
EBU20670
Engine break-in
There is never a more important period in the life of
your engine than the first 20 hours of riding. For
this reason, you should read the following material
carefully.
Since the engine is brand new, do not put an ex-
cessive load on it for the first 20 hours. The various
parts in the engine wear and polish themselves to
the correct operating clearances. During this peri-
od, prolonged full-throttle operation or any condi-
tion that might result in engine overheating must
be avoided.
0–10 hours
Avoid prolonged operation above 1/2 throttle. Vary
the speed of the ATV regularly. Do not operate it at
one set throttle position.
10–20 hours
Avoid prolonged operation above 3/4 throttle. Rev
the engine through the gears freely, but do not use
full throttle at any time.
20 hours and beyond
The ATV can now be operated normally.CAUTION:

ECB00220
If any engine trouble should occur during the
engine break-in period, immediately have a
Yamaha dealer check the ATV.
EBU20721
Parking
When parking the ATV, stop the engine, shift into
first gear, apply the parking brake, and then turn
the fuel cock to “OFF”.

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EBU20860
Parking on a slope
WARNING

EWB00850
Avoid parking on hills or other inclines. Park-
ing on a hill or other incline could cause the
ATV to roll out of control, increasing the
chance of an accident. If you must park on an
incline, place the ATV transversely across the
incline, shift into first gear, stop the engine, ap-
ply the parking brake, and then block the front
and rear wheels with rocks or other objects.
Do not park the ATV at all on hills that are so
steep you could not walk up them easily.
1. Bring the ATV to a stop by applying the brakes
in first gear.
2. Stop the engine and release the clutch lever.
3. With the rear brake applied, apply the parking
brake and slowly release the brake pedal.
EBU20910
Accessories and loading
EBU20920
Accessories
Accessories can affect the handling and control of
your ATV. Keep the following in mind when consid-
ering an accessory or operating an ATV which has
accessories.
1. Locked position
1

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WARNING

EWB01550
Always mount a caution flag on the ATV to
make you more visible when operating in areas
where you might not be seen by other vehicles.
Watch carefully for other vehicles.
Do not ride in areas posted “no trespassing”.
Do not ride on private property without getting per-
mission.Select a large, flat, unpaved area to become famil-
iar with your ATV. Make sure that this area is free
of obstacles and other riders. You should practice
control of the throttle, brakes, shifting procedures,
and turning techniques in this area before trying
more difficult terrain. Always avoid riding on paved
surfaces: the ATV is designed for use on unpaved
surfaces only, and handling maneuvers are more
difficult to perform on pavement.
Set the parking brake and follow the instruction on
page 6-1 to start the engine. Once it has warmed
up you are ready to begin riding your ATV. As you
get on the ATV, be sure not to accidentally move
the shift pedal. Remember that the engine and ex-
haust pipe will be hot when riding and afterwards;
do not allow skin or clothing to come in contact with

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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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make sure you do not lift the front wheels which
could cause you to lose control. If you are unable
to continue up the hill, dismount the ATV on the up-
hill side. Physically turn the ATV around and then
descend the hill.
If you start to roll backwards, DO NOT apply the
rear brake to stop or try to put the ATV in gear. The
ATV could easily tip over backwards. Instead, ap-
ply the front brake gradually, or dismount the ATV
immediately on the uphill side.
WARNING

EWB01731
Use the proper gear and maintain a steady
speed when climbing a hill.
If you lose all forward speed:

Keep weight uphill.

Apply the brakes.

Lock the parking brake after you are
stopped.
If you begin rolling backwards:

Keep weight uphill.

Never apply the rear brake while rolling
backwards. Apply the front brake.

When fully stopped, apply the rear brake as
well, and then lock the parking brake.
Dismount on uphill side or to a side if pointedstraight uphill. Turn the ATV around and re-
mount, following the procedure described in
the Owner’s Manual.
RIDING DOWNHILL
When riding your ATV downhill, shift your weight
as far to the rear and uphill side of the ATV as pos-
sible. Move back on the seat and sit with your arms
straight. Choose a low gear which will allow the en-
gine compression to do most of the braking for
you. Improper braking may cause a loss of trac-