light YAMAHA YFZ450R 2012 User Guide

5-3
5
Brake and clutch levers
Make sure that operation is smooth. Lubricate lever pivoting points if
necessary. 8-41
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 PAGEU18P66E0.book Page 3 Monday, May 16, 2011 4:23 PM

5-7
5Aftermarket 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.
Front:
Manufacturer/model:DUNLOP/KT352 Radial
Size: AT21 x 7R10
Ty p e : Tu b e l e s s
Rear: Manufacturer/model:DUNLOP/KT357 Radial
Size: AT 2 0 x 1 0 R 9
Ty p e : Tu b e l e s s
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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.EBU29952Starting the engine NOTICEECB00150See the “Engine break-in ” section on page 6-4
prior to operating the engine for the first time.1. Set the parking brake.
2. Turn the key to “” (on) and the engine stop
switch to “”.
The following warning lights should come on
for a few seconds, then go off.

Coolant temperature warning light
Fuel level warning light
Engine trouble warning light
NOTICEECB00824If a warning light does not go off, see page 4-2
for the corresponding warning light circuit
check. To avoid possible damage, do not oper-
ate the ATV if a warning light stays on.3. Shift the transmission into neutral. The neutral indicator light should come on, if it does not
come on, have a Yamaha dealer 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.
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6-2
64. 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.NOTICEECB00163For maximum engine life, never accelerate
hard when the engine is cold!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 accelerate
1. Release the throttle lever, apply the front or rear brake, and then release the parking
brake.1. Shift pedal
2. Neutral position
1
2 2 3
4 5
N1
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7-12
7
trol.
[EWB02631]

NOTICE: Do not shift gears without
releasing the throttle. Damage to the engine or
drive train may occur.
[ECB01071]
Use this same procedure as you move into the
higher gears. Be sure to coordinate the use of the
throttle and shift pedal properly.
Avoid higher speeds until you are thoroughly famil-
iar with the operation of your ATV.
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.
TURNING YOUR ATV
WARNING
EWB01771Always follow proper procedures for turning
as described in this Owner ’s Manual. Practice
turning at low speeds before attempting to turn
at faster speeds. Do not turn at speeds too fast
for your skills or the conditions. ATV could go
out of control, causing a collision or overturn.
To achieve maximum traction on unpaved surfac-
es, the two rear wheels turn together at the same
speed. Therefore, unless the wheel on the inside
of the turn is allowed to slip or lose some traction,
the ATV will resist turning. A special turning tech-
nique must be used to allow the ATV to make turns
quickly and easily. It is essential that this skill be
learned first at low speed.
As you approach a curve, slow down and begin to
turn the handlebars in the desired direction. As you
do so, put your weight on the footrest to the outside
of the turn (opposite your desired direction) and
lean your upper body into the turn. Use the throttle
to maintain an even speed through the turn. This
maneuver will let the wheel on the inside of the turn
slip slightly, allowing the ATV to make the turn
properly.
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7-18
7
CROSSING A SLOPE
WARNING
EWB01632Improperly crossing hills or turning on hills
could cause loss of control or cause the ATV to
overturn.
Always follow proper procedures as de-
scribed in the Owner
’s Manual.
Avoid hills with excessively slippery or loose
surfaces.
Avoid crossing the side of a steep hill.
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 as described in the Owner ’s Manual on
level ground. Be very careful when turning
on any hill.Traversing a sloping surface on your ATV requires
you to properly position your weight to maintain
proper balance. Be sure that you have learned the
basic riding skills on flat ground before attempting
to cross a sloping surface. Avoid slopes with slip-
pery surfaces or rough terrain that may upset your
balance. As you travel across a slope, lean your body in the
uphill direction. It may be necessary to correct the
steering when riding on loose surfaces by pointing
the front wheels slightly uphill. When riding on
slopes, be sure not to make sharp turns either up
or down hill.
If your ATV does begin to tip over, gradually steer
in the downhill direction if there are no obstacles in
your path. As you regain proper balance, gradually
steer again in the direction you wish to travel.U18P66E0.book Page 18 Monday, May 16, 2011 4:23 PM

8-8
8
EBU29430TIP
Some maintenance items need more frequent service if you are riding in unusually wet, dusty, sandy or
muddy areas, or at full-throttle.
Replace the fuel hose every five years and if cracked or damaged.
Hydraulic brake service
Regularly check and, if necessary, correct the brake fluid level.
 Every two years replace the internal components of the brake master cylinders and calipers, and
change the brake fluid.
 Replace the brake hoses every four years and if cracked or damaged.23 *Throttle lever 
Check operation.
 Check throttle lever free play, and adjust if neces-
sary.
 Lubricate cable and lever housing. √√√√√
24 *Front and rear brake
switches

Check operation and correct if necessary. √√√√√
25 *Lights and switches 
Check operation and correct if necessary.
 Adjust headlight beams. √√√√√
NO. ITEM
CHECK OR MAINTENANCE
JOB INITIAL EVERY
Whichev- er comes first month136612
km
(mi) 320
(200) 1300
(800) 2500
(1600) 2500
(1600) 5000
(3200)
hours 20 80 160 160 320U18P66E0.book Page 8 Monday, May 16, 2011 4:23 PM

8-15
8
To install the cowling
1. Place the cowling in the original position, and
then tighten the quick fasteners.
2. Install panels C, B and A.EBU29441Checking the spark plug The spark plug is an important engine component,
which should be checked periodically, preferably
by a Yamaha dealer. Since heat and deposits will
cause any spark plug to slowly erode, the spark
plug should be removed and checked in accor-
dance with the periodic maintenance and lubrica-
tion chart. In addition, the condition of the spark
plug can reveal the condition of the engine.
The porcelain insulator around the center elec-
trode of the spark plug should be a medium-to-light
tan (the ideal color when the vehicle is ridden nor-
mally). If the spark plug shows a distinctly different
color, the engine could be operating improperly.
Do not attempt to diagnose such problems your-
self. Instead, have a Yamaha dealer check the ve-
hicle.
If the spark plug shows signs of electrode erosion
and excessive carbon or other deposits, it should
be replaced.
1. Quick fastener
1. Quick fastener
11
1
1
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8-28
82. Remove the tailpipe by pulling it out of the
muffler.
3. Tap the tailpipe lightly, and then use a wire brush to remove any carbon deposits from the
spark arrester portion of the tailpipe and inside
of the tailpipe housing. 4. Insert the tailpipe into the muffler and align the
bolt holes.
5. Install the bolt and tighten it to the specified torque.
6. Remove the purging bolt and the gasket.
1. Tailpipe bolt
2. Tailpipe
1
2
1. Tailpipe
2. Spark arresterTightening torque: Tailpipe bolt:8 Nm (0.8 m ·kgf, 5.8 ft· lbf)
1
2
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8-36
8hold the adjusting bolt with a wrench so
that it does not turn together with the lock-
nut.
[ECB00521]
WARNING
EWB02090Operating with improperly serviced or adjust-
ed brakes could cause the brakes to malfunc-
tion, resulting in reduced braking
performance. This could increase the chance
of a collision or accident. After adjusting the
parking brake free play, block the rear of the
ATV off the ground and spin the rear wheels.
Check to make sure there is no brake drag. If
brake drag is noticed, perform the adjustment
again.EBU24743Brake light switches The brake light, which is activated by the brake
pedal and brake lever, should come on just before
braking takes effect. The brake light switch for the brake pedal can be
adjusted as follows, but the front brake light switch
should be adjusted by a Yamaha dealer.
Turn the rear brake light switch adjusting nut while
holding the brake light switch in place. To make the
brake light come on earlier, turn the adjusting nut
in direction (a). To make the brake light come on
later, turn the adjusting nut in direction (b).
EBU30152Adjusting the clutch lever free play The clutch lever free play must be checked and, if
necessary, adjusted at the intervals specified in the
periodic maintenance and lubrication chart.
Tightening torque:
Locknut (rear brake caliper):16 Nm (1.6 m ·kgf, 12 ft· lbf)1. Rear brake light switch
2. Rear brake light switch adjusting nut
1
2(a) (b)
U18P66E0.book Page 36 Monday, May 16, 2011 4:23 PM