2010 YAMAHA YFZ450R engine

4-10
43. 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.
[ECB00982]
4. Turn the fuel tank cap fully clockwise to make sure it is securely closed.
WARNING
EWB02532Gasoline 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 doctor immediately. If gasoline spills on your skin,
wash with soap and water. If gasoline spills on
your clothing, change your clothes.
NOTICEECB00071Use only unleaded gasoline. The use of leaded
gasoline will cause severe damage to internal
engine parts, such as the valves and piston
rings, as well as to the exhaust system. Your Yamaha engine has been designed to use
premium unleaded gasoline with a research oc-
tane number of 97 or higher. If knocking (or ping-
ing) occurs, use a gasoline of a different brand.
Use of unleaded fuel will extend spark plug life and
reduce maintenance costs.EBU26732SeatTo remove the seat
Insert your hand between the rear of the seat and
the rear fender, pull the seat lock lever and pull up
the seat at the rear.
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: 3.4 L (0.90 US gal, 0.75 Imp.gal)
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5-1
5
EBU19202
PRE-OPERATION CHECKS
EBU19225Inspect 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
EWB00482Failure 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:
ITEMROUTINE PAGE
Fuel • Check fuel level in fuel tank,
and add recommended fuel if neces-
sary.
• Check fuel line for leakage. Correct if necessary. 4-9, 5-4
Engine oil • Check oil level in engine oil tank, and add recommended oil to
specified 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
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5-4
5
EBU19542FuelMake sure that there is sufficient fuel in the tank.
(See page 4-9.)EBU19561Engine oilMake sure that the engine oil is at the specified
level. Add oil as necessary. (See page 8-14.)EBU19632CoolantMake 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. EBU19713Front and rear brakesBrake 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
8-32.) 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 sys-
tem.
Brake fluid level
Check the brake fluid level. Add fluid if necessary.
(See page 8-29.)
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. Specified brake fluid:
DOT 4U1TD61E0.book Page 4 Tuesday, July 8, 2014 11:30 AM

6-1
6
EBU19882
OPERATION
EBU19902Read 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
EWB00632Read 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. EBU29953Starting the engineNOTICEECB00151See 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 stopswitch 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
NOTICEECB00825If 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. NOTICEECB00164For maximum engine life, never accelerate
hard when the engine is cold! EBU20525ShiftingThis 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 ped-
al slightly to reach the neutral position, and then
release the clutch.
EBU20595To start out and accelerate
1. Release the throttle lever, apply the front or rear brake, and then release the parking
brake.
2. Pull the clutch lever to disengage the clutch.1. Shift pedal
2. Neutral position
1
2 2 3
4 5
N1
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6
3. Shift into first gear, and then release the
brake. NOTICE: Always close the throttle
before shifting gears, otherwise damage
to the engine and drive train may result.
[ECB01220]
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, in-
cluding an overturn.
[EWB00732]
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.
EBU20652To decelerate
When slowing down or stopping, release the
throttle 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 en-
gaging a lower gear. Improper use of the brakes or
shifting can cause the tires to lose traction, reduc-
ing control and increasing the possibility of an ac-
cident.
WARNING
EWB00711Make 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. NOTICEECB00181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-
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6-4
6erly lubricated only when the engine is run-
ning. Inadequate lubrication may damage
the transmission.
 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.
EBU20673Engine break-inTIP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 oper-
ate 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.
NOTICEECB00221If any engine trouble should occur during the
engine break-in period, immediately have a
Yamaha dealer check the ATV. EBU26762ParkingWhen parking the ATV, shift into first gear, stop
the engine, and then apply the parking brake.
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6-5
6
EBU20907Parking on a slope
WARNING
EWB00852Avoid parking on hills or other inclines. Parking
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, apply the park-
ing 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
brakes.
2. With the brake pedal applied, shift into first gear and then stop the engine.
3. Apply the parking brake.EBU20911Accessories and loadingEBU20922Genuine Yamaha Accessories
Choosing accessories for your ATV is an impor-
tant decision. Genuine Yamaha Accessories,
which are available only from a Yamaha dealer,
1. Parking brake lever (locked position)U1TD61E0.book Page 5 Tuesday, July 8, 2014 11:30 AM