2012 YAMAHA YFZ450 Owners Manual

5-7
5
Aftermarket tires and rims
The tires and rims that came with your ATV were
designed to match the performance capabilities
and to provide the best combination of handling,
braking, and comfort. Other tires, rims, sizes, and
combinations may not be appropriate.
EBU19840Chassis fasteners Make sure that all nuts, bolts and screws are prop-
erly tightened.
EBU19850Instruments, lights and switches Check that all instruments, lights and switches are
working properly. Correct if necessary.
Fro nt:
Manufacturer/model:DUNLOP/KT851B Bias
Size: AT21 x 7-10
Ty p e : Tu b e l e s s
Rear: Manufacturer/model:DUNLOP/KT355A Radial
Size: AT20 x 10R9
Ty p e : Tu b e l e s s
U1PD60E0.book Page 7 Monday, June 13, 2011 2:57 PM

6-1
6
EBU19881
OPERATION
EBU19901Read the Owner’s Manual carefully before riding
the ATV. If there is a control or function you do not
understand, ask your Yamaha dealer.
WARNING
EWB00631Read 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.EBU20184Starting a cold engine NOTICEECB00150See 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 key to “ON ” and the engine stop
switch to “”. 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.
TIPThis 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:
Position (1):
Cold engine start with ambient temperature
below 5 ° C (40 °F).
Position (2):
Cold engine start with ambient temperature
between 0 ° C (30 °F) and 30 ° C (90 °F).
Position (3):
Cold engine start with ambient temperature
above 25 °C (80 °F).
U1PD60E0.book Page 1 Monday, June 13, 2011 2:57 PM

6-2
6
Ambient temp./starter (choke) position
6. Completely close the throttle lever and start the engine by pushing the start switch.
TIPIf the engine fails to start, release the start switch,
then push it again. Pause a few seconds before
the next attempt. Each cranking should be as short as possible to preserve battery energy. Do not
crank the engine more than 10 seconds on each
attempt.
7. If the engine is started with the starter (choke)
in position (1), the starter (choke) should be
returned to position (2) to warm up the engine.
If the engine is started with the starter (choke)
in position (2), keep the starter (choke) in this
position to warm up the engine.
8. Continue warming up the engine until it idles smoothly, then return the starter (choke) to
position (3) before riding.TIPThe engine is warm when it responds quickly to the
throttle with the starter (choke) turned off.NOTICEECB00163For maximum engine life, never accelerate
hard when the engine is cold!
1. Fully open
2. Half open
3. Closed
4. Starter (choke)
1 2 3
12
3
4
U1PD60E0.book Page 2 Monday, June 13, 2011 2:57 PM

6-3
6
EBU20291Starting a warm engine Follow the same procedure as for starting a cold
engine, with the exception that the starter (choke)
is not required when the engine is warm. Instead,
start the engine with the throttle slightly open.EBU20522Shifting This ATV has a 5-speed forward transmission. The
transmission allows you to control the amount of
power you have available at a given speed or for
starting, accelerating, climbing hills, etc.
To shift into neutral, release the throttle lever, ap-
ply the clutch, and then repeatedly depress the
shift pedal until it stops.
When it stops, it will be in first gear. Raise the pedal
slightly to reach the neutral position, and then re-
lease the clutch.
EBU20592To start out and accelerate1. Release the throttle lever, apply the front or rear brake, and then release the parking
brake.NOTICEECB00200Always 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.1. Shift pedal
2. Neutral position
1
2
U1PD60E0.book Page 3 Monday, June 13, 2011 2:57 PM

6-4
6
3. Shift into first gear, and then release the
brake.
4. Open the throttle gradually and at the same time, release the clutch lever slowly.
WARNING! Opening the throttle abruptly or releasing the clutch lever too quickly
could make the ATV wheelie, which would
increase the chance of an accident, includ-
ing an overturn.
[EWB00731]
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.EBU20650To 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
EWB00710Make 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.NOTICEECB00180
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
the transmission.
U1PD60E0.book Page 4 Monday, June 13, 2011 2:57 PM

6-5
6

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.EBU20672Engine break-in TIP
For ATVs equipped with an odometer or an hour
meter, follow the figures given in km (mi) or the
figures given in hours.
For ATVs not equipped with an odometer or
hour meter, follow the figures given in hours.There is never a more important period in the life of
your engine than the first 320 km (200 mi) or 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 320 km (200 mi) or 20
hours. The various parts in the engine wear and
polish themselves to the correct operating clear-
ances. During this period, prolonged full-throttle
operation or any condition that might result in en-
gine overheating must be avoided.0
–160 km (0 –100 mi) or 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.
160 –320 km (100 –200 mi) or 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.
320 km (200 mi) or 20 hours and beyond
The ATV can now be operated normally.
NOTICEECB00220If any engine trouble should occur during the
engine break-in period, immediately have a
Yamaha dealer check the ATV.EBU20722Parking When parking the ATV, shift into first gear, stop the
engine, apply the parking brake, and then turn the
fuel cock to “OFF ”.
U1PD60E0.book Page 5 Monday, June 13, 2011 2:57 PM

6-6
6
EBU20865Parking on a slope
WARNING
EWB00851Avoid 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.Never park the ATV on hills that are too steep
to walk up easily.
1. Bring the ATV to a stop by applying the front
brake, shift into first gear, and then stop the
engine.
2. With the front and rear brakes applied, apply the parking brake.
3. Release the front and rear brakes.
4. Turn the fuel cock to “OFF ”.
1. Parking brake lever (locked position)U1PD60E0.book Page 6 Monday, June 13, 2011 2:57 PM

6-7
6
EBU20910Accessories and loading EBU20921Genuine Yamaha Accessories
Choosing accessories for your ATV is an important
decision. Genuine Yamaha Accessories, which
are available only from a Yamaha dealer, have
been designed, tested, and approved by Yamaha
for use on your ATV. Many companies with no con-
nection to Yamaha manufacture parts and acces-
sories or offer other modifications for Yamaha
vehicles. Yamaha is not in a position to test the
products that these aftermarket companies pro-
duce. Therefore, Yamaha can neither endorse nor
recommend the use of accessories not sold by
Yamaha or modifications not specifically recom- mended by Yamaha, even if sold and installed by
a Yamaha dealer.
Aftermarket parts, accessories, and modifica-
tions
While you may find aftermarket products similar in
design and quality to genuine Yamaha Accesso-
ries, recognize that some aftermarket accessories
or modifications are not suitable because of poten-
tial safety hazards to you or others. Installing after- market products or having other modifications
performed to your ATV that change any of the ve-
hicle
’s design or operation characteristics can put
you and others at greater risk of serious injury or
death. You are responsible for injuries related to
changes in the vehicle.
Keep the following in mind when considering an
accessory or operating an ATV which has acces-
sories.

Accessories should be rigidly and securely
mounted. An accessory which can shift position
or come off while you are riding could affect your
ability to control the ATV.
Do not mount an accessory where it could inter-
fere with your ability to control the ATV. Exam-
ples include (but are not limited to) a heavy or
bulky object attached to the handlebars which
could make steering difficult, an accessory that
limits your ability to move around on the seat, or
one that limits your view.
Use extra caution when riding an ATV with ac-
cessories. The ATV may handle differently than
it does without accessories.
U1PD60E0.book Page 7 Monday, June 13, 2011 2:57 PM