2012 YAMAHA YFZ450 maintenance

EBU17170
INTRODUCTION
EBU17322Congratulations on your purchase of the Yamaha YFZ450B. This ATV represents the result of many years
of Yamaha experience in the production of fine sporting, touring, and pacesetting racing machines. With the
purchase of this Yamaha, you can now appreciate the high degree of craftsmanship and reliability that have
made Yamaha a leader in these fields.
This manual will provide you with a good basic understanding of the features and operation of this ATV.
This manual includes important safety information. It provides information about special tech-
niques and skills necessary to ride the ATV. It also includes basic maintenance and inspection proce-
dures. If you have any questions regarding the operation or maintenance of your ATV, please consult a
Yamaha dealer.
AN IMPORTANT SAFETY MESSAGE:
Read this manual completely before operating your ATV. Make sure you understand all instructions.
Pay close attention to the warning and notice labels on the ATV.
This ATV should not be ridden by anyone under 16 years of age.
This ATV is a high-performance ATV for off-road use only, for sport-type recreational and competitive use
by experienced operators.
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Parking ....................................................... 6-5
Parking on a slope ..................................... 6-6
Accessories and loading ............................ 6-7
RIDING YOUR ATV ...................................... 7-1 GETTING TO KNOW YOUR ATV............... 7-2
RIDE WITH CARE AND GOOD JUDGMENT .............................................. 7-2
BE CAREFUL WHERE YOU RIDE ............. 7-9
TURNING YOUR ATV .............................. 7-12
CLIMBING UPHILL ................................... 7-13
RIDING DOWNHILL.................................. 7-16
CROSSING A SLOPE............................... 7-18
CROSSING THROUGH SHALLOW WATER ................................................... 7-19
RIDING OVER ROUGH TERRAIN ........... 7-20
SLIDING AND SKIDDING ......................... 7-21
WHAT TO DO IF... .................................... 7-22
WHAT TO DO... ........................................ 7-22
PERIODIC MAINTENANCE AND
ADJUSTMENT ............................................... 8-1 Owner’s manual and tool kit ....................... 8-2
Periodic maintenance chart for the emission control system ........................... 8-3
General maintenance and lubrication chart ......................................................... 8-5 Removing and installing the panel ..............8-9
Checking the spark plug ...........................8-10
Engine oil and oil filter element .................8-14
Coolant .....................................................8-20
Cleaning the air filter element ...................8-24
Cleaning the spark arrester ......................8-28
Adjusting the carburetor ............................8-30
Checking the engine idling speed .............8-30
Adjusting the throttle lever free play .........8-31
Valve clearance ........................................8-31
Brakes .......................................................8-32
Checking the front and rear brake pads ...8-32
Checking the brake fluid level ...................8-33
Changing the brake fluid ...........................8-36
Checking the front brake lever free play ...8-36
Checking the brake pedal height ..............8-36
Adjusting the parking brake free play .......8-37
Brake light switches ..................................8-38
Adjusting the clutch lever free play ...........8-39
Drive chain slack .......................................8-41
Lubricating the drive chain ........................8-43
Checking and lubricating the cables .........8-43
Checking and lubricating the brake and
clutch levers ............................................8-44
Checking the shift pedal ...........................8-45
Checking and lubricating the brake pedal .......................................................8-45
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2-2
2

Always inspect your ATV each time you use it to
make sure it is in safe operating condition. Al-
ways follow the inspection and maintenance
procedures and schedules described in this
manual.
Always keep both hands on the handlebars and
both feet on the footrests of the ATV during op-
eration.
Always go slowly and be extra careful when op-
erating on unfamiliar terrain. Always be alert to
changing terrain conditions when operating the
ATV.
Never operate on excessively rough, slippery or
loose terrain until you have learned and prac-
ticed the skills necessary to control the ATV on
such terrain. Always be especially cautious on
these kinds of terrain.
Always follow proper procedures for turning as
described in this manual. Practice turning at low
speeds before attempting to turn at faster
speeds and never turn at excessive speeds.
Never operate the ATV on hills too steep for the
ATV or for your abilities. Practice on smaller hills
before attempting larger hills.

Always follow proper procedures for climbing
hills as described in this manual. Check the ter-
rain carefully before you start up any hill. Never
climb hills with excessively slippery or loose sur-
faces. Shift your weight forward. Never open the
throttle suddenly or make sudden gear changes.
Never go over the top of a hill at high speed.
Always follow proper procedures for going down
hills and for braking on hills as described in this
manual. Check the terrain carefully before you
start down any hill. Shift your weight backward.
Never go down a hill at high speed. Avoid going
down a hill at an angle that would cause the ve-
hicle to lean sharply to one side. Go straight
down the hill where possible.
Always follow proper procedures for crossing
the side of a hill as described in this manual.
Avoid hills with excessively slippery or loose sur-
faces. Shift your weight to the uphill side of the
ATV. Never attempt to turn the ATV around on
any hill until you have mastered the turning tech-
nique described in this manual on level ground.
Avoid crossing the side of a steep hill if possible.
Always use proper procedures if you stall or roll
backwards when climbing a hill. To avoid stall-
ing, use the proper gear and maintain a steady
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4-10
4
doctor immediately. If gasoline spills on your
skin, wash with soap and water. If gasoline
spills on your clothing, change your clothes.
NOTICEECB00070Use only unleaded gasoline. The use of leaded
gasoline will cause severe damage to internal
engine parts, such as the valves and piston
rings, as well as to the exhaust system.Your Yamaha engine has been designed to use
premium unleaded gasoline with a research oc-
tane number of 97 or higher. If knocking (or ping-
ing) occurs, use a gasoline of a different brand.
Use of unleaded fuel will extend spark plug life and
reduce maintenance costs.EBU18820Fuel cock The fuel cock supplies fuel from the tank to the car-
buretor while also filtering it.
The fuel cock lever positions are explained as fol-
lows and shown in the illustrations. OFF
With the fuel cock lever in this position, fuel will not
flow. Always turn the fuel cock lever to this position
when the engine is not running.
1. Arrow mark positioned over
“OFF”
1
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5-1
5
EBU19201
PRE-OPERATION CHECKS
EBU19224Inspect your vehicle each time you use it to make sure the vehicle is in safe operating condition. Always
follow the inspection and maintenance procedures and schedules described in the Owner’s Manual.
WARNING
EWB00481Failure to inspect or maintain the vehicle properly increases the possibility of an accident or equip-
ment damage. Do not operate the vehicle if you find any problem. If a problem cannot be corrected
by the procedures provided in this manual, have the vehicle inspected by a Yamaha dealer.Before using this vehicle, check the following points:
ITEM ROUTINE PAGE
Fuel 
Check fuel level in fuel tank, and add recommended fuel if neces-
sary.
 Check fuel line for leakage. Correct if necessary. 4-8, 5-4
Engine oil 
Check oil level in engine oil tank, and add recommended oil to spec-
ified level if necessary.
 Check ATV for oil leakage. Correct if necessary. 5-4, 8-14
Coolant 
Check coolant level in reservoir, and add recommended coolant to
specified level if necessary.
 Check cooling system for leakage. Correct if necessary. 5-4, 8-20
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7-5
7Do not operate after or while consuming alco-
hol or drugs.
The operator ’s performance capability is reduced
by the influence of alcohol or drugs. Consuming al-
cohol or drugs could seriously affect your judg-
ment, cause you to react more slowly, and affect
your balance and perception. WARNING! Never
consume alcohol or drugs before or while driv-
ing this ATV. You increase your chance of an
accident.
[EWB01421]
Pre-operation checks
Always inspect your ATV each time you use it to
make sure the ATV is in safe operating condition.
Perform the pre-operation checks listed on page
5-1. Always follow the inspection and maintenance
procedures and schedules described in the Own-
er ’s Manual. WARNING! Failure to inspect the
ATV before operating it and to maintain it prop-
erly increases the possibility of an accident or
equipment damage.
[EWB01431]
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
1. Protective clothing
2. Goggles
3. Gloves
4. Boots
5. HelmetU1PD60E0.book Page 5 Monday, June 13, 2011 2:57 PM

8-1
8
EBU28783
PERIODIC MAINTENANCE AND ADJUSTMENT
EBU21674Periodic inspection, adjustment, and lubrication
will keep your vehicle in the safest and most effi-
cient condition possible. Safety is an obligation of
the vehicle owner/operator. The most important
points of vehicle inspection, adjustment, and lubri-
cation are explained on the following pages.
WARNING
EWB01841Failure to properly maintain the vehicle or per-
forming maintenance activities incorrectly may
increase your risk of injury or death during ser-
vice or while using the vehicle. If you are not fa-
miliar with vehicle service, have a Yamaha
dealer perform the service.
WARNING
EWB02562Turn off the engine when performing mainte-
nance unless otherwise specified.
A running engine has moving parts that can
catch on body parts or clothing and electri-
cal parts that can cause shocks or fires.

Running the engine while servicing can lead
to eye injury, burns, fire, or carbon monoxide
poisoning - possibly leading to death. See
page 2-3 for more information about carbon
monoxide.
WARNING
EWB02690Brake discs, calipers, drums, and linings can
become very hot during use. To avoid possible
burns, let brake components cool before
touching them.The intervals given in the periodic maintenance
charts should be considered as a general guide
under normal riding conditions. However, DE-
PENDING ON THE WEATHER, TERRAIN, GEO-
GRAPHICAL LOCATION, AND INDIVIDUAL
USE, THE MAINTENANCE INTERVALS MAY
NEED TO BE SHORTENED.
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8-2
8
EBU27111Owner’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.
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.
TIPIf you do not have the tools or experience required
for a particular job, have a Yamaha dealer perform
it for you.
1. Low-pressure tire gauge
2. Owner
’s tool kit
3. Owner ’s manual
3
2
1
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