2008 YAMAHA PW50 engine

INSTRUMENT AND CONTROL FUNCTIONS
3-6
1
2
3
4
5
6
7
8
9O (on)
With the lever in this position, fuel flows
to the carburetor. Normal riding is done
with the lever in this position.

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Starter (choke) lever “”
Starting a cold engine requires a richer
air-fuel mixture, which is supplied by
the starter (choke).
Move the lever in direction (a) to turn on
the starter (choke).
Move the lever in direction (b) to turn off
the starter (choke).
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Kickstarter
To start the engine, fold out the kick-
starter lever, move it down lightly with
your foot until the gears engage, and
then push it down smoothly but force-
fully.
1. Arrow mark pointing to “O” (on)
1

1. Starter (choke) lever “”
1 (a)
(b)

1. Kickstarter
1

PRE-OPERATION CHECKS
4-2
2
3
45
6
7
8
9

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Pre-operation check list
ITEM CHECKS PAGE
Fuel

Check fuel level in fuel tank.

Refuel if necessary.

Check fuel line for leakage.3-3
2-stroke engine oil

Check oil level in oil tank.

If necessary, add recommended oil to specified level.

Check vehicle for oil leakage.3-5
Middle and final gear cases

Check vehicle for grease leakage. 6-8
Front brake

Check operation.

Lubricate cable if necessary.

Check lever free play.

Adjust if necessary.6-14, 6-15
Rear brake

Check operation.

Lubricate cable if necessary.

Check lever free play.

Adjust if necessary.6-14, 6-15
Throttle grip

Make sure that operation is smooth.

Check cable free play.

If necessary, have Yamaha dealer adjust cable free play and lubricate cable
and grip housing.6-11, 6-16
Control cables

Make sure that operation is smooth.

Lubricate if necessary.6-15
Wheels and tires

Check for damage.

Check tire condition and tread depth.

Check air pressure.

Correct if necessary.6-11, 6-13
Brake levers

Make sure that operation is smooth.

Lubricate lever pivoting points if necessary.6-16
Centerstand

Make sure that operation is smooth.

Lubricate pivot if necessary.6-17

PRE-OPERATION CHECKS
4-3
1
2
3
4
5
6
7
8
9

Chassis fasteners

Make sure that all nuts, bolts and screws are properly tightened.

Tighten if necessary.—
Engine stop switch

Check operation.3-1
ITEM CHECKS PAGE

5-1
2
3
4
56
7
8
9

OPERATION AND IMPORTANT RIDING POINTS
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WARNING

EWA14531

This model is designed for
off-road use only. Become thor-
oughly familiar with all operat-
ing controls and their functions
before riding. Consult a Yamaha
dealer regarding any control or
function that you do not thor-
oughly understand.

Never start the engine or oper-
ate it in a closed area for any
length of time. Exhaust fumes
are poisonous, and inhaling
them can cause loss of con-
sciousness and death within a
short time. Always make sure
that there is adequate ventila-
tion.
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Starting and warming up a
cold engine
1. Turn the fuel cock lever to “O” (on).
2. Set the engine stop switch to
“START”.
3. Turn the starter (choke) on and
completely close the throttle. (See
page 3-6.)
4. While applying the front or rear
brake, start the engine by pushing
the kickstarter lever down.
5. After starting the engine, move the
starter (choke) back halfway.
CAUTION:

ECA11130
For maximum engine life, always
warm the engine up before starting
off. Never accelerate hard when the
engine is cold!
6. When the engine is warm, turn the
starter (choke) off and set the en-
gine stop switch to “RUN”.
NOTE:

The engine is warm when it responds
normally to the throttle with the starter
(choke) turned off.
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Starting a warm engine
Follow the same procedure as for start-
ing 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.
NOTE:

If the engine does not start after sever-
al kicks, try again with the throttle 1/4
to 1/2 open.

OPERATION AND IMPORTANT RIDING POINTS
5-2
1
2
3
4
5
6
7
8
9

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Starting off
NOTE:

Before starting off, allow the engine to
warm up.
1. While applying the rear brake le-
ver, push the motorcycle off the
centerstand.
2. Completely close the throttle.
3. Set the engine stop switch to
“RUN”.
4. Check for oncoming off-road vehi-
cles, and then slowly turn the throt-
tle grip in order to take off.
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Acceleration and deceleration
The speed can be adjusted by opening
and closing the throttle. To increase the
speed, turn the throttle grip in direction
(a). To reduce the speed, turn the throt-
tle grip in direction (b).
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Braking
1. Close the throttle completely.
2. Apply both front and rear brakes
simultaneously while gradually in-
creasing the pressure.
Front(a)(b)

OPERATION AND IMPORTANT RIDING POINTS
5-3
2
3
4
56
7
8
9 Rear
WARNING

EWA14571

Avoid braking hard or suddenly
(especially when leaning over to
one side), otherwise the motor-
cycle may skid or overturn.

Keep in mind that braking on
wet surfaces is much more diffi-
cult.

Ride slowly down a hill, as brak-
ing downhill can be very diffi-
cult.
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Engine break-in
There is never a more important period
in the life of your engine than the first 5
hours of riding. It is also important to ac-
custom the rider to the motorcycle dur-
ing this time. Please read the following
information carefully.
Since the engine is brand new, do not
put an excessive load on it for the first 5
hours of operation. The various parts in
the engine wear and polish themselves
to the correct operating clearances.
During this period, prolonged full-throt-
tle operation or any condition that might
result in engine overheating must be
avoided. However, momentary
full-throttle operation under load (i.e.,
two to three seconds maximum) does
not harm the engine. Each full-throttle
acceleration should be followed with a
substantial rest period for the engine.
To allow the engine to cool down from
the temporary buildup of heat, cruise at
a lower engine speed.
After the first 5 hours of operation, thor-
oughly check the motorcycle for loose
parts, oil leakage and any other prob-
lems. Be sure to inspect and make ad-justments thoroughly, especially
cables. In addition, check all fittings and
fasteners for looseness, and tighten if
necessary.
CAUTION:

ECA10270
If any engine trouble should occur
during the engine break-in period,
immediately have a Yamaha dealer
check the vehicle.

OPERATION AND IMPORTANT RIDING POINTS
5-4
1
2
3
4
5
6
7
8
9

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Parking
When parking, stop the engine, and
then turn the fuel cock lever to “S”
(stop).
WARNING

EWA10310

Since the engine and exhaust
system can become very hot,
park in a place where pedestri-
ans or children are not likely to
touch them.

Do not park on a slope or on soft
ground, otherwise the vehicle
may overturn.

PERIODIC MAINTENANCE AND MINOR REPAIR
6-2
1
2
3
4
5
6
7
8
9

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Periodic maintenance chart for the emission control system
NOTE:


From 18 months, repeat the maintenance intervals starting from 6 months.

Items marked with an asterisk should be performed by a Yamaha dealer as they require special tools, data and technical
skills.
NO. ITEM CHECK OR MAINTENANCE JOBINITIALTHEREAFTER
EVERY
1
month3
months6
months6
months12
months
1*Fuel line
Check fuel hoses for cracks or damage.Replace if necessary.
2Spark plugCheck condition.Adjust gap and clean.Replace if necessary.
3Air filter elementClean with solvent.Replace if necessary.
4*CarburetorCheck engine idling speed and starter operation.Adjust if necessary.Clean.
5*Cylinder head and
exhaust systemCheck for leakage.Tighten if necessary.Decarbonize if necessary.
6*Spark arresterClean.