warning YAMAHA YFZ450 2012 User Guide

4-8
4
EBU18720Fuel tank cap Remove the fuel tank cap by turning it counter-
clockwise.
EBU18814Fuel Make sure there is sufficient gasoline in the tank.
WARNING
EWB02521Gasoline and gasoline vapors are extremely
flammable. To avoid fires and explosions and
to reduce the risk of injury when refueling, fol-
low these instructions.1. Before refueling, turn off the engine and besure that no one is sitting on the vehicle. Nev-
er refuel while smoking, or while in the vicinity
1. Shift pedal
1
1. Fuel tank cap
1
U1PD60E0.book Page 8 Monday, June 13, 2011 2:57 PM

4-9
4of sparks, open flames, or other sources of ig-
nition such as the pilot lights of water heaters
and clothes dryers.
2. Do not overfill the fuel tank. When refueling, be sure to insert the pump nozzle into the fuel
tank filler hole. Stop filling when the fuel reach-
es the bottom of the filler tube. Because fuel
expands when it heats up, heat from the en-
gine or the sun can cause fuel to spill out of
the fuel tank.
3. Wipe up any spilled fuel immediately.NOTICE: Immediately wipe off spilled fuel
with a clean, dry, soft cloth, since fuel may
deteriorate painted surfaces or plastic
parts.
[ECB00981]
4. Turn the fuel tank cap fully clockwise to make sure it is securely closed.
WARNING
EWB02531Gasoline is poisonous and can cause injury or
death. Handle gasoline with care. Never siphon
gasoline by mouth. If you should swallow
some gasoline or inhale a lot of gasoline vapor,
or get some gasoline in your eyes, see your
1. Maximum fuel level
2. Fuel tank filler tube
Recommended fuel:PREMIUM UNLEADED GASOLINE ONLY
For Europe: PREMIUM UNLEADED GASO-
LINE ONLY with a research octane number
of 97 or higher
Fuel tank capacity: 10.0 L (2.64 US gal, 2.20 Imp.gal)
Fuel reserve amount: 1.9 L (0.50 US gal, 0.42 Imp.gal)
U1PD60E0.book Page 9 Monday, June 13, 2011 2:57 PM

4-13
4
EBU18993Adjusting the front shock absorber as-
semblies The spring preload can be adjusted to suit the rid-
er’s weight and the riding conditions.
WARNING
EWB00400Always adjust the shock absorber assemblies
on the left and right side to the same setting.
Uneven adjustment can cause poor handling
and loss of stability, which could lead to an ac-
cident.
Adjust the spring preload as follows.
Turn the spring preload adjusting ring in direction
(a) to increase the spring preload and thereby
harden the suspension, and in direction (b) to de-
crease the spring preload and thereby soften the
suspension.
Align the appropriate notch in the adjusting ring
with the position indicator on the shock absorber.TIPA special wrench can be obtained at a Yamaha
dealer to make this adjustment.
1. Projection
2. Seat holder
1
2
1. Spring preload adjusting ring
2. Special wrench
3. Position indicator
1 2 3
4 5
(a)
(b) 1
2
3
U1PD60E0.book Page 13 Monday, June 13, 2011 2:57 PM

4-17
48. Place the air filter case in the original position,
connect the air intake duct, and then tighten
the clamp screw at the carburetor side.
NOTICE: Make sure that the air intake duct
is properly connected to the carburetor,
and that the clamp screw is tightened se-
curely.
[ECB01170]
9. Install the bolts, install the hose joint, and then connect the hoses.
10. Install the seat.
WARNING
EWB00450This shock absorber assembly contains highly
pressurized nitrogen gas. If the shock absorb-
er assembly is damaged, it could explode
causing injury or property damage. Shock ab-
sorber cylinder damage could also result in
poor handling which could cause an accident.
Do not tamper with or attempt to open the
cylinder assembly.
Do not subject the shock absorber assembly
to an open flame or other high heat.

Do not deform or damage the cylinder in any
way.
Do not dispose of a damaged or worn out
shock absorber assembly yourself. Take the
shock absorber assembly to a Yamaha deal-
er for any service.
Tightening torque: Locknut:44 Nm (4.4 m ·kgf, 32 ft· lbf)
U1PD60E0.book Page 17 Monday, June 13, 2011 2:57 PM

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
U1PD60E0.book Page 1 Monday, June 13, 2011 2:57 PM

5-5
5
EBU19761Throttle lever Check the operation of the throttle lever. It must
open smoothly and spring back to the idle position
when released. Have a Yamaha dealer correct if
necessary.EBU19770Drive chain Check the condition of the drive chain and check
the drive chain slack. Lubricate and adjust the
drive chain as necessary. (See page 8-41.)EBU19794Tires Check tire pressure regularly to make sure it is at
the recommended specifications. Also check for
wear and damage.
Tire pressure
Use the low-pressure tire gauge to check and ad-
just tire pressures when the tires are cold. Tire
pressures must be equal on both sides.
WARNING! Operation of this vehicle with im- proper tire pressure may cause severe injury
or death from loss of control or rollover. Tire
pressure below the minimum specified could also cause the tire to dislodge from the rim un-
der severe riding conditions.
[EWB02541]
Set tire
pressures to the following specifications:
The low-pressure tire gauge is included as stan-
dard equipment. Make two measurements of the
tire pressure and use the second reading. Dust or
dirt in the gauge could cause the first reading to be
incorrect. Recommended tire pressure:
Fron t25.0 kPa (0.250 kgf/cm ², 3.6 psi)
Rear 30.0 kPa (0.300 kgf/cm ², 4.4 psi)
Minimum tire pressure: Fron t22.0 kPa (0.220 kgf/cm ², 3.2 psi)
Rear 27.0 kPa (0.270 kgf/cm ², 4.0 psi)
Maximum tire seating pressure: Fron t250 kPa (2.5 kgf/cm² , 36 psi)
Rear 250 kPa (2.5 kgf/cm² , 36 psi)
U1PD60E0.book Page 5 Monday, June 13, 2011 2:57 PM

5-6
5Tire wear limit
When the tire groove decreases to 3 mm (0.12 in)
due to wear, replace the tire. Tire information
This ATV is equipped with tubeless tires with
valves.
WARNING
EWB02551Use of improper tires on this ATV may cause
loss of control, increasing your risk of an acci-
dent.After extensive tests, only the tires listed below
have been approved for this model by Yamaha
Motor Co., Ltd.
1. Low-pressure tire gauge
1
1. Tire wear limit
U1PD60E0.book Page 6 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

6-4
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

6-6
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