YAMAHA YFZ450 2012 Owner's Manual

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
U1PD60E0.book Page 2 Monday, June 13, 2011 2:57 PM

2-3
2speed when climbing a hill. If you stall or roll
backwards, follow the special procedure for
braking described in this manual. Dismount on
the uphill side or to a side if pointed straight up-
hill. Turn the ATV around and remount, following
the procedure described in this manual.

Always check for obstacles before operating in a
new area.
Never attempt to operate over large obstacles,
such as large rocks or fallen trees. Always follow
proper procedures when operating over obsta-
cles as described in this manual.
Always be careful when skidding or sliding.
Learn to safely control skidding or sliding by
practicing at low speeds and on level, smooth
terrain. 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 con-
trol.
Never operate an ATV in fast flowing water or in
water deeper than that recommended in this
manual. Remember that wet brakes may have
reduced stopping ability. Test your brakes after
leaving water. If necessary, apply them several
times to let friction dry out the linings.

Always use the size and type of tires specified in
this manual.
Always maintain proper tire pressure as de-
scribed in this manual.
Never modify an ATV through improper installa-
tion or use of accessories.
Never exceed the stated load capacity for an
ATV. Cargo should be properly distributed and
securely attached. Reduce speed and follow in-
structions in this manual for carrying cargo or
pulling a trailer. Allow greater distance for brak-
ing.
WARNING
EWB00072Avoid Carbon Monoxide Poisoning
All engine exhaust contains carbon monoxide,
a deadly gas. Breathing carbon monoxide can
cause headaches, dizziness, drowsiness, nau-
sea, confusion, and eventually death.
Carbon Monoxide is a colorless, odorless,
tasteless gas which may be present even if you
do not see or smell any engine exhaust. Deadly
levels of carbon monoxide can collect rapidly
and you can quickly be overcome and unable
to save yourself. Also, deadly levels of carbon
monoxide can linger for hours or days in en-
U1PD60E0.book Page 3 Monday, June 13, 2011 2:57 PM

2-4
2
closed or poorly ventilated areas. If you experi-
ence any symptoms of carbon monoxide
poisoning, leave the area immediately, get
fresh air, and SEEK MEDICAL TREATMENT.

Do not run engine indoors. Even if you try to
ventilate engine exhaust with fans or open
windows and doors, carbon monoxide can
rapidly reach dangerous levels.
Do not run engine in poorly ventilated or par-
tially enclosed areas such as barns, garages,
or carports.
Do not run engine outdoors where engine
exhaust can be drawn into a building
through openings such as windows and
doors.
WARNING
EWB02591When transporting the ATV in another vehicle,
be sure it is kept upright and that the fuel cock
is in the
“OFF ” position. Otherwise, fuel may
leak out of the carburetor or fuel tank.U1PD60E0.book Page 4 Monday, June 13, 2011 2:57 PM

3-1
3
EBU17680
DESCRIPTION
EBU17690Left view
EBU17700Right view
1. Headlights
2. Fuel cock
3. Starter (choke)
4. Fuse
5. Tail/brake light
6. Coolant reservoir
7. Shift pedal
8. Engine oil tank
123 45
6
7
8
1. Spark arrester
2. Seat
3. Fuel tank cap
4. Radiator cap
5. Oil filter element
6. Brake pedal1
23
4
5
6
U1PD60E0.book Page 1 Monday, June 13, 2011 2:57 PM

3-2
3
EBU17712Controls and instrumentsTIPThe ATV you have purchased may differ slightly
from the figures shown in this manual.1. Clutch lever
2. Handlebar switches
3. Parking brake
4. Main switch
5. Throttle lever
6. Brake lever
1
2
3
4
5
6
U1PD60E0.book Page 2 Monday, June 13, 2011 2:57 PM

4-1
4
EBU17733
INSTRUMENT AND CONTROL FUNCTIONS
EBU17760Main switch The positions of the main switch are as follows:
ON
All electrical systems are supplied with power. The
headlights and taillight come on when the light
switch is on, and the engine can be started. The
key cannot be removed.
OFF
All electrical systems are off. The key can be re-
moved.
1. Main switch
OFF ON
1
U1PD60E0.book Page 1 Monday, June 13, 2011 2:57 PM

4-2
4
EBU17805Indicator light and warning light EBU17860Neutral indicator light“”
This indicator light comes on when the transmis-
sion is in the neutral position.EBU17930Coolant temperature warning light “”
This warning light comes on when the engine over-
heats. When this occurs during operation, stop the
engine as soon as it is safe to do so and allow it to
cool down for about 10 minutes. The electrical circuit of the warning light can be
checked according to the following procedure.
1. Set the engine stop switch to “” and turn
the key to “ON ”.
2. Shift the transmission into the neutral position or pull the clutch lever.
3. Push the start switch. If the warning light does not come on while the start switch is pushed,
have a Yamaha dealer check the electrical cir-
cuit.
NOTICEECB00010
The engine may overheat if the ATV is over-
loaded. In this case, reduce the load to spec-
ification.
Start the engine after making sure that the
warning light is out. Continuous use while
the warning light is on may cause damage to
the engine.
1. Neutral indicator light “N”
2. Coolant temperature warning light “”
12
U1PD60E0.book Page 2 Monday, June 13, 2011 2:57 PM

4-3
4
EBU18061Handlebar switches EBU18080Engine stop switch“/”
Set this switch to “” before starting the engine.
The engine stop switch controls the ignition and
stops the engine when it is running. Use this switch
to stop the engine in an emergency situation. The
engine will not start or run when this switch is set
to “” .
EBU18101Start switch “”
Push this switch to crank the engine with the start-
er. See the starting instructions on page 6-1 prior
to starting the engine.EBU18154Light switch “//OFF ”
Set this switch to “” to turn on the low beams
and the taillight. Set the switch to “” to turn on
the high beams and the taillight. Set the switch to
“ OFF ” to turn off all the lights.NOTICEECB00043Do not use the headlights with the engine
turned off for an extended period of time, oth-
erwise the battery may discharge to the point
that the starter motor will not operate properly.
If this should happen, remove the battery and
recharge it. (See page 8-48.)EBU18282Throttle lever Once the engine is running, pushing the throttle le-
ver will increase the engine speed.
1. Light switch “/ /OFF”
2. Engine stop switch “/”
3. Start switch “”
1
23
U1PD60E0.book Page 3 Monday, June 13, 2011 2:57 PM

4-4
4
Regulate the speed of the ATV by varying the
throttle position. Because the throttle is spring-
loaded, the ATV will decelerate, and the engine will
return to an idle any time the throttle lever is re-
leased.
Before starting the engine, check the throttle to be
sure it is operating smoothly. Make sure it returns
to the idle position as soon as the lever is released.
EBU18323Speed limiter Your ATV is equipped with an adjustable speed
limiter. The speed limiter keeps the throttle from
fully opening, even when the throttle lever is
pushed to the maximum.
1. Loosen the locknut.
2. To increase the maximum engine power avail- able and the maximum speed of the ATV, turn
the adjusting screw in direction (a). To de-
crease the maximum engine power available
and the maximum speed of the ATV, turn the
adjusting screw in direction (b). Do not turn
the adjusting screw out more than 12 mm
(0.47 in) or the throttle cable could be dam-
aged. Always make sure the throttle lever free
play is adjusted to 2.0– 4.0 mm (0.08–0.16 in).
(See page 8-31.) WARNING! Improper ad-
justment of the speed limiter and throttle
could cause throttle cable damage or im-
proper throttle operation. You could lose
control, resulting in an accident.
[EWB00241]
1. Throttle leverU1PD60E0.book Page 4 Monday, June 13, 2011 2:57 PM

4-5
43. Tighten the locknut.
EBU18382Clutch lever The clutch lever is located on the left handlebar
and the ignition circuit cut-off system is incorporat-
ed in the clutch lever holder. To disengage the
clutch, pull the clutch lever toward the handlebar
grip. To engage the clutch, release the clutch lever.
The clutch lever should be pulled rapidly and re-
leased slowly for smooth clutch operation. (See
page 6-1 for a description of the ignition circuit cut-
off system.)
EBU18411Brake lever The brake lever is located at the right handlebar
grip. To apply the front brake, pull the brake lever
toward the handlebar grip.
1. Locknut
2. Adjusting screw
3. No more than 12 mm (0.47 in)
3 1
2
(a)(b)
1. Clutch lever
U1PD60E0.book Page 5 Monday, June 13, 2011 2:57 PM