2003 YAMAHA YFM350R engine

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1-CONTENTS
LOCATION OF THE WARNING AND
SPECIFICATION LABELS ....................... 1-1
SAFETY INFORMATION ......................... 2-1
DESCRIPTION AND MACHINE
IDENTIFICATION .................................... 3-1
Identification number records ............... 3-3
Key identification number ..................... 3-5
Vehicle identification number ............... 3-5
Model label ........................................... 3-7
CONTROL FUNCTIONS ......................... 4-1
Main switch........................................... 4-1
Indicator lights ...................................... 4-3
Handlebar switches .............................. 4-5
Throttle lever ........................................ 4-9
Speed limiter ...................................... 4-11
Clutch lever ........................................ 4-13
Brake lever ......................................... 4-13
Brake pedal ........................................ 4-15
Parking brake ..................................... 4-17
Shift pedal .......................................... 4-21
Drive select lever ................................ 4-21
1234
Fuel tank cap ..................................... 4-23
Fuel cock............................................ 4-23
Starter (choke) ................................... 4-25
Seat.................................................... 4-27
Front shock absorber adjustment ...... 4-29
Rear shock absorber adjustment ....... 4-31
PRE-OPERATION CHECKS ................... 5-1
Front and rear brakes .......................... 5-5
Fuel ...................................................... 5-9
Engine oil ........................................... 5-13
Chain.................................................. 5-15
Throttle lever ...................................... 5-17
Fittings and fasteners......................... 5-17
Lights ................................................. 5-17
Switches............................................. 5-17
Battery................................................ 5-19
Tires ................................................... 5-19
How to measure tire pressure ............ 5-23
Tire wear limit..................................... 5-25
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OPERATION ............................................6-1
Starting a cold engine ...........................6-3
Starting a warm engine .........................6-9
Warming up...........................................6-9
Drive select lever operation and
reverse driving ..................................6-11
Shifting ................................................6-15
To start out and accelerate: ................6-17
To decelerate: .....................................6-21
Engine break-in ...................................6-23
Parking ................................................6-27
Parking on a slope ..............................6-29
Accessories and loading .....................6-31
RIDING YOUR ATV..................................7-1
Getting to know your ATV .....................7-3
Ride with care and good
judgement ...........................................7-5
Be careful where you ride ...................7-27
Turning your ATV ................................7-39
Climbing uphill.....................................7-45
Riding downhill ....................................7-55
Crossing a slope .................................7-59
Crossing through shallow water ..........7-63
Riding over rough terrain ....................7-67
Sliding and skidding ............................7-69
What to do if ........................................7-73
67
What to do .......................................... 7-73
PERIODIC MAINTENANCE AND
ADJUSTMENT ......................................... 8-1
Owner’s manual and tool kit ................. 8-3
Periodic maintenance/lubrication.......... 8-7
Engine oil ............................................ 8-15
Spark plug inspection ......................... 8-25
Air filter cleaning ................................. 8-29
Carburetor adjustment ........................ 8-35
Idle speed adjustment ........................ 8-37
Throttle lever adjustment .................... 8-39
Valve clearance adjustment ............... 8-39
Front and rear brake pad
inspection ......................................... 8-41
Brake fluid level check ........................ 8-43
Brake fluid replacement ...................... 8-47
Front brake lever free play.................. 8-49
Brake pedal height adjustment ........... 8-51
Parking brake adjustment ................... 8-53
Adjusting the rear brake light switch ... 8-57
Clutch lever free play adjustment ....... 8-59
Drive chain slack check ...................... 8-61
Drive chain slack adjustment .............. 8-63
Lubricating the drive chain.................. 8-65
Cable inspection and lubrication......... 8-67
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2-1
SAFETY INFORMATION
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AN ATV IS NOT A TOY AND CAN BE HAZARD-OUS TO OPERATE.
An ATV handles differently
from other vehicles including motorcycles and
cars. A collision or rollover can occur quickly, even
during routine maneuvers such as turning and
riding on hills or over obstacles, if you fail to take
proper precautions.
SEVERE INJURY OR DEATH can result if you do
not follow these instructions:


Read this manual and all labels carefully and
follow the operating procedures described.


Never operate an ATV without proper instruc-
tion.


Always follow the age recommendation:
– A child under 16 years old should never oper-
ate an ATV with engine size greater than 90cc.
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2-17
WARNING


Always turn off the engine when refueling.


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


Do not spill gasoline on the engine or ex-
haust pipe/muffler when refueling. Never
refuel while smoking, or while in the vicini-
ty of sparks, open flames, or other sources
of ignition such as the pilot lights of water
heaters and clothes dryers. Gasoline can
catch fire and you could be burned.


When transporting the machine in another
vehicle, be sure it is kept upright and that
the fuel cock is in the “OFF” position. Oth-
erwise, fuel may leak out of the carburetor
or fuel tank.


Gasoline is poisonous. If you should swal-
low some gasoline or inhale a lot of gaso-
line vapor, or get some gasoline in your
eyes, see your doctor immediately. If gaso-
line spills on your skin, wash with soap
and water. If gasoline spills on your cloth-
ing, change your clothes.
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4-1
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CONTROL FUNCTIONS
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Main switch
Functions of the respective switch positions are as
follows:
ON:
The engine can be started only at this position and
the headlights and taillight come on when the light
switch is on.
OFF:
All electrical circuits are switched off. The key can
be removed in this position.
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4-5 1. Light switch “LIGHTS”
2. Engine stop switch “ENG. STOP”
3. Start switch “START”
1. Contacteur d’éclairage “LIGHTS”
2. Coupe-circuit du moteur “ENG. STOP”
3. Contacteur du démarreur “START”
1. Interruptor de luces “LIGHTS”
2. Interruptor de paro del motor “ENG. STOP”
3. Interruptor de arranque “START”
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Handlebar switches
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Light switch “LIGHTS”
Set the switch to the “LO” position to turn on the
low beam and the taillight.
Set the switch to the “HI” position to turn on the
high beam and the taillight.
Set the switch to the “OFF” position to turn off all of
the lights.CAUTION:_ Do not use the headlights with the engine
turned off for more than thirty minutes. The
battery may discharge to the point that the
starter motor will not operate properly. If this
should happen, remove the battery and re-
charge it. _
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4-7 1. Light switch “LIGHTS”
2. Engine stop switch “ENG. STOP”
3. Start switch “START”
1. Contacteur d’éclairage “LIGHTS”
2. Coupe-circuit du moteur “ENG. STOP”
3. Contacteur du démarreur “START”
1. Interruptor de luces “LIGHTS”
2. Interruptor de paro del motor “ENG. STOP”
3. Interruptor de arranque “START”
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Engine stop switch “ENG. STOP”
Make sure that the engine stop switch is in the
“RUN” position before starting the engine. The en-
gine stop switch controls ignition and can be used
at all times to stop the engine, especially in an
emergency. The engine will not start or run when
the engine stop switch is turned to “OFF”.
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Start switch “START”
The starter motor cranks the engine when this
switch is pushed.CAUTION:
See the starting instructions on page 6-3 prior
to starting the engine.
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4-9 1. Throttle lever
1. Levier d’accélération
1. Palanca de aceleración
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Throttle lever
Once the engine is running, movement of the
throttle lever will increase the engine speed.
Regulate the speed of the machine by varying the
throttle position. Because the throttle is spring-
loaded, the machine will decelerate, and the en-
gine will return to an idle any time the hand is re-
moved from the throttle lever.
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.
WARNING
Malfunction of the throttle could make it diffi-
cult to speed up or slow down when you need
to. This could cause an accident. Check the
operation of the throttle lever before you start
the engine. If the throttle does not work
smoothly, check for the cause. Correct the
problem before riding the ATV or consult a
Yamaha dealer.
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