engine YAMAHA YFM50S 2004 Owners Manual

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 ...............3-7
Model label ...........................................3-9
CONTROL FUNCTIONS..........................4-1
Main switch ...........................................4-1
Indicator lights ......................................4-3
Handlebar switches ..............................4-3
Engine stop switch with cord (lanyard).....4-7
Throttle lever ......................................4-11
Speed limiter ......................................4-13
Front brake lever ................................4-17Rear brake lever .................................4-17
Parking brake .....................................4-19
Shift lever ...........................................4-21
Fuel tank cap ......................................4-21
Fuel cock ............................................4-23
Choke lever ........................................4-25
Seat ....................................................4-27
PRE-OPERATION CHECKS ...................5-1
Front and rear brakes ...........................5-5
Fuel ......................................................5-9
Engine oil ............................................5-11
Final gear oil .......................................5-15
Throttle lever ......................................5-17
Fittings and fasteners .........................5-17
Switches .............................................5-17
Battery ................................................5-17
Tires ...................................................5-19
How to measure tire pressure ............5-23
Tire wear limit .....................................5-25
EBU00015
CONTENTS
1
2
3
4
5
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OPERATION ............................................6-1
Starting a cold engine ...........................6-3
Starting a warm engine ......................6-11
Warming up ........................................6-11
To start out and accelerate .................6-13
To decelerate .....................................6-17
Engine break-in ..................................6-19
Parking ...............................................6-23
Parking on a slope ..............................6-25
Accessories and loading ....................6-27
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 ....................................7-43
Riding downhill ...................................7-55
Crossing a slope .................................7-59
Crossing through shallow water .........7-63Riding over rough terrain ....................7-67
Sliding and skidding ...........................7-69
What to do if ......................................7-73
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 ............................................8-13
Final gear oil .......................................8-19
Spark plug inspection .........................8-23
Air filter cleaning .................................8-27
Carburetor adjustment ........................8-35
Idle speed adjustment ........................8-37
Valve clearance adjustment ...............8-39
Cam chain adjustment ........................8-39
Front and rear brake shoe
inspection .........................................8-41
Front brake lever free play
adjustment ........................................8-436
7
8
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2-1
EBU14320
AN ATV IS NOT A TOY AND CAN BE HAZ-
ARDOUS 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 precau-
tions.
SEVERE INJURY OR DEATH can result if you
do not follow these instructions:
8Read this manual and all labels carefully and
follow the operating procedures described.
8Never operate an ATV without proper instruc-
tion.
8Always follow the age recommendation:
– A child under 6 years old should never operate
an ATV with engine size greater than 50 cc.
– A child under 12 years old should never operate
an ATV with engine size greater than 70 cc.
– A child under 16 years old should never operate
an ATV with engine size greater than 90 cc.
qSAFETY INFORMATION
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TEACHING YOUR CHILD TO OPERATE THE
ATV
w
Never let your child ride an ATV without
close adult supervision (a child under 6
should not ride this ATV even with adult
supervision).
Promptly correct your child if he or she
begins to ride beyond his or her abilities
and, if necessary, intervene by pulling the
cord (lanyard) to stop the engine.
If the child rides beyond his or her abilities,
or rides in terrain that is too difficult, he or
she may lose control of the ATV, causing an
accident.
Introduce new riding areas slowly and make
sure the riding area matches your child’s
skill level.
2-15
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Choose an appropriate riding area
Select an area appropriate for your child to learn
to ride. (See page 7-27.) Follow the instructions
in the Riding Your ATV section of this manual.
Choose a large, flat off-road area that is free of
obstacles and away from other vehicles.
Supervise every use of the ATV
Because an adult must supervise every ATV
operator under age 16, you should closely watch
your child every time he or she uses the ATV.
Be ready to intervene immediately if the child is
not operating according to your guidelines. This
ATV is fitted with an engine stop switch cord
(lanyard) device that will let you stop the engine
remotely as you walk behind the vehicle.
2-21
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ENGINE STOP SWITCH CORD
This model has an engine stop switch cord (lan-
yard) designed for use by an adult supervising
the child operating the ATV. When using the
engine stop switch cord, be sure the speed lim-
iter on the handlebar is adjusted to limit the ATV
to a walking speed. (See page 4-13.)
1. Push the clip on the end of the engine stop
switch cord under the engine shut-off
switch (black button).
2. Put your fingers in the loop at the other
end of the cord.
3. As your child is riding, walk behind the
ATV, closely watching his or her actions as
well as the path ahead.
4. If there is a potential hazard ahead or if
your child is not riding correctly, pull firmly
on the cord (lanyard) to stop the engine.
Because the ATV will continue to roll for
some distance, allow extra time and dis-
tance to pull the cord before a potentially
hazardous situation might be encountered.
2-23
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2-27
w
8Always turn off the engine when refueling.
8Do not refuel right after the engine has
been running and is still very hot.
8Do not spill gasoline on the engine or
exhaust pipe/muffler when refueling.
Never refuel while smoking, or while in the
vicinity of sparks, open flames, or other
sources of ignition such as the pilot lights
of water heaters and clothes dryers.
Gasoline can catch fire. You could be
burned.
8When transporting the machine 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 carbu-
retor or fuel tank.
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2-29
8Gasoline 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
gasoline spills on your skin, wash with
soap and water. If gasoline spills on your
clothing, change your clothes.
w
Always operate your ATV in an area with
adequate ventilation. Never start or run the
engine in a closed area. Exhaust fumes are
poisonous and may cause loss of con-
sciousness and death within a short time.
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3-1
EBU00032
DESCRIPTION AND MACHINE
IDENTIFICATION
1. Seat 8. Rear brake lever
2. Front cover 9. Parking brake
3. Fuel cock 10. Neutral indicator light
4. Fuse 11. Front brake lever
5. Engine stop switch with 12. Throttle lever
cord (lanyard) 13. Main switch
6. Footrest 14. Fuel tank cap
7. Shift lever 15. Handlebar switches
NOTE:
The machine you have purchased may differ
slightly from those shown in the figures of this
manual.
1
2
6
89
0q
w e r t
3
5
6 74
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4-1
EBU00040
CONTROL FUNCTIONS
EBU00042
Main switch
Functions of the respective switch positions are
as follows:
ON:
The engine can be started only at this position.
OFF:
All electrical circuits are switched off. The key
can be removed in this position.
OFF ON
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