YAMAHA YFZ450 2008 Manual Online

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RIDING OVER ROUGH TERRAIN
Riding over rough terrain should be done with cau-
tion. Look out for obstacles which could cause
damage to the ATV or could lead to an upset or ac-
cident. Be sure to keep your feet firmly mounted on
the footboards at all times. Avoid jumping the ATV
as loss of control and damage to the ATV may re-
sult.
WARNING

EWB01650
Before operating in a new area, check for ob-
stacles. Never attempt to ride over large obsta-
cles, such as large rocks or fallen trees. Whenyou go over obstacles, always follow proper
procedures as described in the Owner’s Manu-
al.
SLIDING AND SKIDDING
Care should be used when riding on loose or slip-
pery surfaces since the ATV may slide. If unex-
pected and uncorrected, sliding could lead to an
accident.
To reduce the tendency for the front wheels to slide
in loose or slippery conditions, positioning your
weight over the front wheels will sometimes help.
If the rear wheels of your ATV start to slide side-
ways, control can usually be regained (if there is
room to do so) by steering in the direction of the
1. Air filter case check hose
1

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slide. Applying the brakes or accelerating is not
recommended until you have corrected the slide.
With practice, over a period of time, skill at con-
trolled sliding can be developed. The terrain
should be chosen carefully before attempting such
maneuvers, since both stability and control are re-
duced. Bear in mind that sliding maneuvers should
always be avoided on extremely slippery surfaces
such as ice, since all control may be lost.
WARNING

EWB01661
Learn to safely control skidding or sliding by
practicing at low speeds and on level, smoothterrain.
On extremely slippery surfaces, such as ice,
go slowly and be very cautious in order to re-
duce the chance of skidding or sliding out of
control.
WHAT TO DO IF...
This section is designed to be a reference guide
only. Be sure to read each section on riding tech-
niques completely.
WHAT TO DO...

If your ATV doesn’t turn when you want it to:
Bring the ATV to a stop and practice the turning
maneuvers again. Be sure you are putting your
weight on the footboard to the outside of the
turn. Position your weight over the front wheels
for better control. (See page 7-12.)

If your ATV begins to tip while turning:
Lean more into the turn to regain balance. If nec-
essary, gradually let off the throttle and/or steer
to the outside of the turn. (See page 7-12.)

If your ATV starts to slide sideways:
Steer in the direction of the slide if you have the
room. Applying the brakes or accelerating is not
recommended until you have corrected the

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slide. (See page 7-20.)

If your ATV can’t make it up a hill you are trying
to climb:
Turn the ATV around if you still have forward
speed. If not, stop, dismount on the uphill side of
the ATV and physically turn the ATV around. If
the ATV starts to slip backwards, DO NOT USE
THE REAR BRAKE – the ATV may tip over on
top of you. Dismount the ATV on the uphill side.
(See page 7-14.)

If your ATV is traversing a sloping surface:
Be sure to ride with your weight positioned to-
wards the uphill side of the ATV to maintain
proper balance. If the ATV starts to tip, steer
down the hill (if there are no obstacles in your
way) to regain balance. If you discover that the
ATV is going to tip over, dismount on the uphill
side. (See page 7-14.)

If your ATV encounters shallow water:
Ride slowly and carefully through slow moving
water, watching for obstacles. Be sure to let wa-
ter drain from the ATV and CHECK YOUR
BRAKES FOR PROPER OPERATION when
you come out of the water. Do not continue to
ride your ATV until you have regained adequate
braking ability. (See page 7-18.)

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EBU28781
PERIODIC MAINTENANCE AND MINOR REPAIR
EBU21670
Safety is an obligation of the owner. Periodic in-
spection, adjustment and lubrication will keep your
ATV in the safest and best operating condition
possible. The most important points of inspection,
adjustment, and lubrication are explained on the
following pages.
The intervals given in the periodic maintenance
and lubrication chart should be considered as a
general guide under normal riding conditions.
However, DEPENDING ON THE WEATHER,
TERRAIN, GEOGRAPHICAL LOCATION, AND
INDIVIDUAL USE, THE MAINTENANCE INTER-
VALS MAY NEED TO BE SHORTENED.
WARNING

EWB01840
Never service an engine while it is running.
Moving parts can catch clothing or parts of the
body, causing injury. Electrical components
can cause shocks or start fires. Turn off the en-
gine when performing maintenance unless
otherwise specified. Have a Yamaha dealer
perform the service if you are not familiar with
maintenance work.
EBU27110
Owner’s manual and tool kit
Be sure to put this owner’s manual in the plastic
bag and to always carry it as well as the owner’s
tool kit and the low-pressure tire gauge in their re-
spective compartments under the seat.
1. Low-pressure tire gauge
2. Owner’s tool kit
3. Owner’s manual
3 21

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The service information included in this manual
and the tools provided in the owner’s tool kit are in-
tended to assist you in the performance of preven-
tive maintenance and minor repairs. However,
additional tools such as a torque wrench may be
necessary to perform certain maintenance work
correctly.
NOTE:

If you do not have the tools or experience required
for a particular job, have a Yamaha dealer perform
it for you.
WARNING

EWB01850
Never modify this ATV through improper in-
stallation or use of accessories, as it may
cause changes in handling, which in some sit-
uations could lead to an accident. All parts and
accessories added to this ATV should be gen-
uine Yamaha or equivalent components de-
signed for use on this ATV and should be
installed and used according to instructions. If
you have questions, consult an authorized
Yamaha ATV dealer.

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EBU21742
Periodic maintenance chart for the emission control system
NOTE:


For ATVs not equipped with an odometer or an hour meter, follow the month maintenance intervals.

For ATVs equipped with an odometer or an hour meter, follow the km (mi) or hours maintenance inter-
vals. However, keep in mind that if the ATV isn’t used for a long period of time, the month maintenance
intervals should be followed.

Items marked with an asterisk should be performed by a Yamaha dealer as they require special tools,
data and technical skills.
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
*
Fuel line


Check fuel hoses for cracks or other damage, and
replace if necessary.
√√√
2 Spark plug

Check condition and clean, regap, or replace if
necessary.
√√√√√
3
*
Valves


Check valve clearance and adjust if necessary.
√ √√√
4
*
Carburetor


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

Check engine idling speed and adjust if neces-
sary.
√√√√
5
*
Crankcase breather
system


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

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6
*
Exhaust system

Check for leakage and replace gasket(s) if neces-
sary.

Check for looseness and tighten all screw clamps
and joints if necessary.
√√√
7 Spark arrester

Clean.
√√√
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

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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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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

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20 Engine oil

Change.

Check ATV for oil leakage, and correct if neces-
sary.
√ √√√
21Engine oil filter ele-
ment

Clean or replace if necessary.
√√√
22 Cooling system

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

Replace coolant. Every 2 years
23
*
Moving parts and
cables

Lubricate.
√√√√
24
*
Throttle lever hous-
ing and cable


Check operation and correct if necessary.

Check throttle cable free play and adjust if neces-
sary.

Lubricate throttle lever housing and cable.
√√√√√
25
*
Front and rear brake
switches

Check operation and correct if necessary.
√√√√√
26
*
Lights and switches

Check operation and correct if necessary.

Adjust headlight beams.
√√√√√
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 80 160 160 320