2002 YAMAHA YFM80R engine

7-7
Riding your machine requires skills acquired
through practice over a period of time.
Take the time to learn the basic techniques well
before attempting more difficult maneuvers.
Not recommended for children under 12
years of age.wA child under 12 should never operate an
ATV with engine size greater than 70cc. Use
by children of ATVs that are not recommend-
ed for their age can lead to severe injury or
death of the child.
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1. Locknut 2 Adjuster1. Contre-écrou 2. Dispositif de réglage1. Contratuerca 2. Ajustador
7-17
Speed limiter
For riders inexperienced with this model, this model
is equipped with a speed limiter in the throttle lever
housing. The speed limiter limits the power and top
speed of the ATV. Turning the screw in decreases
top speed, and turning it out increases top speed.
This model also has an air intake restrictor plate to
limit the amount of engine power available.
Yamaha recommends that all beginners start off
with the speed limiter turned in and the air intake
restrictor plate installed to limit the amount of speed
available while they learn. The limiter may be grad-
ually adjusted to increase maximum speed as the
beginner becomes more familiar with operating the
ATV. Parents should decide when to adjust the
ATV for more power as their youngster’s riding
skills improve. Once the ATV rider can operate with
skill at the top speed permitted by adjusting the
speed limiter alone, the air intake restrictor plate
can be removed. Since removal of this plate will
result in a significant increase in power, turn the
speed limiter completely back in again; adjust it out
in stages as you did before.
Adjusting for maximum throttle lever movement
without removing the air intake restrictor plate will
cause the engine to run roughly at higher speeds.
q
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7-35
Select a large, flat area off-road to become
familiar with your ATV. Make sure that this area
is free of obstacles and other riders. You should
practice control of the throttle, brakes, shifting
procedures, and turning techniques in this area
before trying more difficult terrain. Always avoid
riding on paved surfaces: the ATV is designed
for off-road use only, and handling maneuvers
are more difficult to perform on pavement.
Set the parking brake and follow the instruction
on page 6-3 to start the engine. Once it has
warmed up you are ready to begin riding your
ATV. As you get on the ATV, be sure not to
accidentally move the shift pedal. Remember
that the engine and exhaust pipe will be hot
when riding and afterwards; do not allow skin or
clothing to come in contact with these compo-
nents.
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7-37
With the engine idling, lift the shift pedal to the
1st gear position and then release the parking
brake. Apply the throttle slowly and smoothly.
The centrifugal clutch will engage and you will
start to accelerate. Once the ATV has attained
adequate speed, release the throttle and lift the
shift pedal to the 2nd gear position. Release the
shift pedal and apply the throttle smoothly. Use
this same procedure as you move into the high-
er gears. Be sure to coordinate the use of the
throttle and shift pedal properly. If the throttle is
applied too abruptly or if the throttle is not
released during shifting, or if the shift pedal is
not released before applying the throttle, the
front wheels may lift off the ground resulting in a
loss of directional control. Avoid higher speeds
until you are thoroughly familiar with the opera-
tion of your ATV.
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7-39
cCDo not shift gears without releasing the
throttle. Damage to the engine or drive train
may occur.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 engaging a lower gear. Improper use of
the brakes or shifting can cause the tires to lose
traction, reducing control and increasing the
possibility of an accident.wMake sure the engine has sufficiently slowed
before shifting to a lower gear. Engaging a
lower gear when the engine speed is too
high could cause the wheels to stop rotating.
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7-57
RIDING DOWNHILL
When riding your ATV downhill, shift your weight
as far to the rear and uphill side of the ATV as
possible. Move back on the seat and sit with
your arms straight. Choose a low gear which will
allow the engine compression to do most of the
braking for you. Improper braking may cause a
loss of traction.
Use caution while descending a hill with loose or
slippery surfaces. Braking ability and traction
may be adversely affected by these surfaces.
Improper braking may also cause a loss of trac-
tion.
Whenever possible, ride your ATV straight
downhill. Avoid sharp angles which could allow
the ATV to tip or roll over. Carefully choose your
path and ride no faster than you will be able to
react to obstacles which may appear.
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8-1
EBU00516
PERIODIC
MAINTENANCE AND
ADJUSTMENT
Periodic inspection, adjustment and lubrication
will keep your machine in the safest and most
efficient condition possible. Safety is an obliga-
tion of the machine owner. The most important
points of machine inspection, adjustment and
lubrication are explained on the following pages.wNever service an engine while it is running.
Moving parts can catch clothing or parts of
the body, causing injury. Electrical compo-
nents can cause shocks or can start fires.
Turn off the engine when performing mainte-
nance unless otherwise specified. Have a
Yamaha dealer perform service if you are not
familiar with machine service.
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8-7
EBU00262PERIODIC MAINTENANCE/LUBRICATION
INITIAL EVERY
ITEM ROUTINE 1 3 6 6 1
month months months months year
Valves*9Check valve clearance.
9Adjust if necessary.2 222
Cam chain*9Check chain tension.
9Adjust if necessary.2 222
9Check condition.
Spark plug9Adjust gap and clean.22222
9Replace if necessary.
Air filter element9Clean. Every 20 ~ 40 hours.
9Replace if necessary. (more often in wet or dusty areas)
Carburetor*9Check idle speed/choke lever operation.
2222
9Adjust if necessary.
Crankcase breather9Check breather hose for cracks or damage.
system*9Replace if necessary.222
9Check for leakage.
Exhaust system*9Retighten if necessary.222
9Replace gasket if necessary.
Fuel line*9Check fuel hose for cracks or damage.
222
9Replace if necessary.
Engine oil9Replace (warm engine before draining).2 222
Final gear oil9Check oil level/oil leakage.
22
9Replace every 12 months.
Brakes*9Check operation.
22222
9Adjust if necessary.
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