engine YAMAHA YFM250R 2008 User Guide

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NOTE:

If knocking or pinging occurs, use a different brand
of gasoline or higher octane grade.CAUTION:
ECB00070
Use 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.WARNING
EWB00310

Do not overfill the fuel tank. Fuel expands
when it heats up. If the fuel tank is overfilled,
fuel could spill out due to heat from the en-
gine or the sun.

Be careful not to spill fuel, especially on the
engine or exhaust pipe which can cause a
fire and severe injury. Wipe up any spilled
fuel immediately.

Do not refuel right after the engine has been
running and is still very hot.

Be sure the fuel tank cap is closed securely.
EBU18820
Fuel cock
The fuel cock supplies fuel from the tank to the car-
buretor while also filtering it.
1. Fuel level
2. Filler tube
Recommended fuel:
UNLEADED GASOLINE ONLY
For Europe: Regular unleaded gasoline only
with a research octane number of 91 or high-
er
Fuel tank capacity:
9.0 L (2.38 US gal) (1.98 Imp.gal)
Fuel reserve amount:
1.0 L (0.26 US gal) (0.22 Imp.gal)

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The fuel cock lever positions are explained as fol-
lows and shown in the illustrations.
OFF
With the fuel cock lever in this position, fuel will not
flow. Always turn the fuel cock lever to this position
when the engine is not running.
ON
With the fuel cock lever in this position, fuel flows
to the carburetor. Turn the fuel cock lever to this
position when starting the engine and riding.

1. Arrow mark positioned over “OFF”
OFF

1. Arrow mark positioned over “ON”
ON

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RES
This indicates reserve. With the fuel cock lever in
this position, the fuel reserve is made available.
Turn the fuel cock lever to this position if you run
out of fuel while riding. When this occurs, refuel as
soon as possible and be sure to turn the fuel cock
lever back to “ON”!
EBU18840
Starter (choke)
Starting a cold engine requires a richer air-fuel mix-
ture, which is supplied by the starter (choke).
Move the starter (choke) in direction (a) to turn onthe starter (choke).
Move the starter (choke) in direction (b) to turn off
the starter (choke).
See the “Starting a cold engine” section on page
6-1 for proper operation.
EBU18890
Seat
To remove the seat
Insert your hand between the rear of the seat and
the rear fender, pull the seat lock lever upward and
pull up the seat at the rear.
1. Arrow mark positioned over “RES”
RES

1. Starter (choke)
(a)(b)1

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EBU19200
PRE-OPERATION CHECKS
EBU19222
Pre-operation check list
Before operating this ATV, be sure to check the items listed in the following table.
WARNING

EWB00480
Always inspect your ATV each time you use it to make sure it is in safe operating condition.
Always follow the inspection and maintenance procedures and schedules described in the Owner’s
Manual. Failure to inspect increases the possibility of an accident or equipment damage.
NOTE:

The maintenance of some items in the table has to be performed by a Yamaha dealer. Refer to the periodic
maintenance charts on page 8-3 to determine which service should be performed by a Yamaha dealer.
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.4-7, 5-3
Engine oil

Check oil level in engine, and add recommended oil to specified
level if necessary.

Check ATV for oil leakage. Correct if necessary.5-3, 8-10
Front brake

Check operation. If soft or spongy, have Yamaha dealer bleed
hydraulic system.

Check brake pads for wear, and replace if necessary.

Check brake fluid level in reservoir, and add recommended brake
fluid to specified level if necessary.

Check hydraulic system for leakage. Correct if necessary.5-3, 8-22, 8-23, 8-26

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EBU19540
Fuel
Make sure that there is sufficient fuel in the tank.
(See page 4-7.)
WARNING

EWB00520

Do not overfill the fuel tank. Fuel expands
when it heats up. If the fuel tank is overfilled,
fuel could spill out due to heat from the en-
gine or the sun.

Be careful not to spill fuel, especially on the
engine or exhaust pipe which can cause a
fire and severe injury. Wipe up any spilled
fuel immediately.

Do not refuel right after the engine has been
running and is still very hot.

Be sure the fuel tank cap is closed securely.
EBU19560
Engine oil
Make sure that the engine oil is at the specified lev-
el. Add oil as necessary. (See page 8-10.)
EBU19710
Front 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 8-26.) 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 8-23.)
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-Recommended brake fluid:
DOT 4

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EBU19880
OPERATION
EBU19900
Read the Owner’s Manual carefully before riding
the ATV.
WARNING

EWB00630
Read 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. If there is a control or func-
tion you do not understand, ask your Yamaha
dealer.
EBU20101
Starting a cold engine
WARNING

EWB00640
Always make sure all control cables work
smoothly before you begin riding in cold
weather. If the control cables are frozen or do
not work smoothly, you could be unable to
control the ATV, which could lead to an acci-
dent or collision.
CAUTION:

ECB00150
See 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 main switch to “ON” and the engine
stop switch to “RUN”.
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.
NOTE:

This 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:

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Position (1):

Cold engine start with ambient temperature be-
low 5 °C (40 °F).
Position (2):

Cold engine start with ambient temperature be-
tween 0 °C (30 °F) and 30 °C (90 °F).
Position (3):

Cold engine start with ambient temperature
above 25 °C (80 °F).
Ambient temp./starter (choke) position
6. Completely close the throttle lever and start
the engine by pushing the start switch.
NOTE:

If 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
1. Fully open
2. Half open
3. Closed
4. Starter (choke)
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attempt.
7. If the engine is started with the starter (choke)
in position (1), the starter (choke) should be
returned to position (2) to warm up the engine.
If the engine is started with the starter (choke)
in position (2), keep the starter (choke) in this
position to warm up the engine.
CAUTION:

ECB00160
For maximum engine life, always warm the en-
gine up before starting off. Never accelerate
hard when the engine is cold!
8. Continue warming up the engine until it idles
smoothly, then return the starter (choke) to
position (3) before riding.
NOTE:

The engine is warm when it responds normally to
the throttle with the starter (choke) turned off.
EBU20291
Starting 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.
EBU20520
Shifting
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, return the throttle lever to the
closed position, apply the clutch, and then repeat-
edly 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.
1. Shift pedal
2. Neutral position
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EBU20570
To start out and accelerate
1. Release the throttle lever.
CAUTION:

ECB00200
Always 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.
3. Shift into first gear.
4. Open the throttle gradually and at the same
time, release the clutch lever slowly.
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.
WARNING

EWB00730
Opening the throttle abruptly or releasing the
clutch lever too quickly could make the ATVwheelie, which would increase the chance of
an accident, including an overturn.
EBU20650
To 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

EWB00710
Make 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.
CAUTION:

ECB00180

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

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for long distances. The transmission is prop-
erly 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.
EBU20672
Engine break-in
NOTE:


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 andpolish 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.
CAUTION:

ECB00220
If any engine trouble should occur during the
engine break-in period, immediately have a
Yamaha dealer check the ATV.
EBU20721
Parking
When parking the ATV, stop the engine, shift into
first gear, apply the parking brake, and then turn