2012 YAMAHA YFZ450 brake

4-7
4
WARNING
EWB00220
Always set the parking brake before starting
the engine. The ATV could start moving un-
expectedly if the parking brake is not ap-
plied. This could cause loss of control or a
collision.
Always be sure you have released the park-
ing brake before you begin to ride. The brake
could overheat if you ride the ATV without re-
leasing the parking brake. You could lose
braking performance which could cause an
accident. You could also wear out the brakes
prematurely.EBU18530Shift pedal This ATV is equipped with a constant-mesh 5-
speed transmission. The shift pedal is located on
the left side of the engine and is used in combina-
tion with the clutch when shifting.
1. Parking brake lever (locked position)
1. Parking brake lever (unlocked position)U1PD60E0.book Page 7 Monday, June 13, 2011 2:57 PM

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5
Front brake
Check operation. If soft or spongy, have Yamaha dealer bleed hy-
draulic system.
 Check brake pads for wear, and replace if necessary.
 Check brake fluid level in reservoir, and add specified brake fluid to
specified level if necessary.
 Check hydraulic system for leakage. Correct if necessary. 5-4, 8-32, 8-33, 8-36
Rear brake 
Check operation. If soft or spongy, have Yamaha dealer bleed hy-
draulic system.
 Check brake pads for wear, and replace if necessary.
 Check brake fluid level in reservoir, and add specified brake fluid to
specified level if necessary.
 Check hydraulic system for leakage. Correct if necessary. 5-4, 8-32, 8-33, 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 lever free play, and adjust if necessary. 5-5, 8-31
Control cables Make sure that operation is smooth. Lubricate if necessary. 8-43
Drive chain 
Check chain slack, and adjust if necessary.
 Check chain condition. Lubricate if necessary. 5-5, 8-41, 8-43
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
Shift pedal 
Make sure that operation is smooth.
 Correct if necessary. 8-45
Brake pedal 
Make sure that operation is smooth. Lubricate pedal pivoting point if
necessary. 8-45
ITEM ROUTINE PAGEU1PD60E0.book Page 2 Monday, June 13, 2011 2:57 PM

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Brake and clutch levers
Make sure that operation is smooth. Lubricate lever pivoting points if
necessary. 8-44
Chassis fasteners Make sure that all nuts, bolts and screws are properly tightened. 5-7
Instruments, lights and
switches 
Check operation, and correct if necessary. 5-7
ITEM ROUTINE PAGE
U1PD60E0.book Page 3 Monday, June 13, 2011 2:57 PM

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EBU19541Fuel Make sure that there is sufficient fuel in the tank.
(See page 4-8.)EBU19560Engine oil Make sure that the engine oil is at the specified lev-
el. Add oil as necessary. (See page 8-14.)EBU19631Coolant Make sure that the coolant is at the specified level.
Add coolant as necessary. (See page 8-20.)TIPThe coolant level must be checked on a cold en-
gine since the level varies with engine tempera-
ture.EBU19712Front 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,
have a Yamaha dealer check the brake system.
Brake fluid level
Check the brake fluid level. Add fluid if necessary.
(See page 8-33.)
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 8-32.) Specified brake fluid:
DOT 4
U1PD60E0.book Page 4 Monday, June 13, 2011 2:57 PM

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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

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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

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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

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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