engine YAMAHA YFM50S 2004 Owner's Guide

6-17
EBU00208
To 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 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.
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Make sure the engine has sufficiently slowed
before shifting to a lower gear. Engaging a
lower gear when the engine speed is too
high could make the wheels stop rotating.
This could cause loss of control, an accident
and injury. It could also cause engine or
drive train damage.
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6-19
EBU02091
Engine break-in
There is never a more important period in the
life of your machine than the period between
zero and 20 hours.
For this reason, we ask that you carefully read
the following material. Because the engine is
brand new, you must not put an excessive load
on it for the first several hours of running. During
the first 20 hours, the various parts in the engine
wear and polish themselves to the correct oper-
ating clearances.
During this period, prolonged full throttle opera-
tion or any condition which might result in exces-
sive engine heating must be avoided. However,
momentary (2–3 seconds maximum) full throttle
operation under load does not harm the engine.
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6-21
Each full throttle acceleration sequence should
be followed with a substantial rest period for the
engine by cruising at lower r/min so the engine
can rid itself of the temporary build up of heat.
If any abnormality is noticed during this period,
consult a Yamaha dealer.
0–10 hours:
8Avoid continuous operation above half throt-
tle. Allow a cooling off period of five to ten
minutes after every hour of operation. Vary
the speed of the machine from time to time.
Do not operate it at one set throttle position.
10–20 hours:
8Avoid prolonged operation above 3/4 throttle.
Rev the machine freely through the gears but
do not use full throttle at any time.
After break-in:
8Avoid prolonged full throttle operation. Vary
speeds occasionally.
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6-23
EBU00211
Parking
When parking, stop the engine and shift into
neutral. Turn the fuel cock to “OFF” and apply
the parking brake.q
1
1. Lock plate1. Plaque de verrouillage1. Placa de bloqueo
1. Locked position
1. Verrouillé1. Posición bloqueada
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6-25
EBU14340
Parking on a slope
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Avoid 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, shift the transmission into the
drive position, apply the parking brake, and
then block the front and rear wheels with
rocks or other objects.
Do not park the ATV at all on hills that are so
steep you could not walk up them easily.
1. Bring the ATV to a stop by applying the
brakes in the drive position.
2. Stop the engine.
3. With the rear brake lever applied, apply the
parking brake and slowly release the brake
lever.
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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 6 years
of age.
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A child under 6 should never operate an ATV
with engine size greater than 50cc. Use by
children of ATVs that are not recommended
for their age can lead to severe injury or
death of the child.
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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. 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 components.
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7-37
With the engine idling, shift the transmission into
the drive position and then release the parking
brake. Apply the throttle slowly and smoothly.
The centrifugal clutch will engage and you will
start to accelerate. If the throttle is applied too
abruptly, 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 operation of your ATV.
When slowing down or stopping, release the
throttle and apply the brakes smoothly and
evenly. Improper use of the brakes can cause
the tires to lose traction, reducing control and
increasing the possibility of an accident.
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7-55
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. Allow the engine compres-
sion 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.
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Never 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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