engine YAMAHA PW50 2008 User Guide

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
EAU40771
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.
EAU40883
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.
EAU16660
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

EAU41000
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.
EAU16780
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).
EAU41011
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.
EAU42030
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

EAU40721
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

EAU41741
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.

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

The air filter needs more frequent service if you are riding in unusually wet or dusty areas.
10
*Transmission oil
Check for oil leakage .Correct if necessary.Change.
11
*Front and rear brake
lever pivot
Apply lithium-soap-based grease (all-purpose
grease) lightly.
12
*Centerstand pivot
Check operation.Apply lithium-soap-based grease (all-purpose
grease) lightly.
13
*Shock absorber
assemblies
Check operation and for oil leakage.Replace if necessary.
14
*Control cable
Apply Yamaha chain and cable lube or engine oil
10W-30 lightly.
15
*Throttle grip housing
and cable
Check operation and free play.Apply Yamaha chain and cable lube or engine oil
10W-30 lightly. NO. ITEM CHECK OR MAINTENANCE JOBINITIALTHEREAFTER
EVERY
1
month3
months6
months6
months12
months

PERIODIC MAINTENANCE AND MINOR REPAIR
6-5
2
3
4
5
67
8
9

EAU19603
Checking the spark plug
The spark plug is an important engine
component, which is easy to check.
Since heat and deposits will cause any
spark plug to slowly erode, the spark
plug should be removed and checked
in accordance with the periodic mainte-
nance and lubrication chart. In addition,
the condition of the spark plug can re-
veal the condition of the engine.
To remove the spark plug
1. Remove the spark plug cap.
2. Remove the spark plug as shown,
with the spark plug wrench includ-
ed in the owner’s tool kit.
To check the spark plug
1. Check that the porcelain insulator
around the center electrode of the
spark plug is a medium-to-light tan
(the ideal color when the vehicle is
ridden normally).
NOTE:

If the spark plug shows a distinctly dif-
ferent color, the engine could be oper-
ating improperly. Do not attempt to
diagnose such problems yourself. In-
stead, have a Yamaha dealer check
the vehicle.
2. Check the spark plug for electrode
erosion and excessive carbon or
other deposits, and replace it ifnecessary.
To install the spark plug
1. Measure the spark plug gap with a
wire thickness gauge and, if nec-
essary, adjust the gap to specifica-
tion.
2. Clean the surface of the spark plug
1. Spark plug cap
1

1. Spark plug wrench
1

Specified spark plug:
NGK/BP4HS (AUS)(NZL)
NGK/BPR4HS
(AUT)(BEL)(CAN)(CHE)(DEU)
(DNK)(ESP)(FIN)(FRA)(GBR)(GRC)
(IRL)(NLD)(NOR)(PRT)(SWE)(ZAF)
DENSO/W14FPL (AUS)(NZL)
1. Spark plug gap
Spark plug gap:
0.6–0.7 mm (0.024–0.028 in)
1

PERIODIC MAINTENANCE AND MINOR REPAIR
6-6
1
2
3
4
5
6
7
8
9
gasket and its mating surface, and
then wipe off any grime from the
spark plug threads.
3. Install the spark plug with the
spark plug wrench, and then tight-
en it to the specified torque.
NOTE:

If a torque wrench is not available when
installing a spark plug, a good estimate
of the correct torque is 1/4–1/2 turn
past finger tight. However, the spark
plug should be tightened to the speci-
fied torque as soon as possible.
4. Install the spark plug cap.
EAU41100
Removing the power
reduction plate
To obtain full engine performance ca-
pability, removing the power reduction
plate is required.
WARNING

EWA14580
Always let the exhaust system cool
prior to touching exhaust compo-
nents.
1. Remove the exhaust manifold by
removing the bolts.
2. Remove the gasket.
3. Remove the power reduction
plate.
NOTE:

Store the power reduction plate with the
owner’s manual so that it is readily
available whenever you want to reduce
the engine power.
4. Install the exhaust manifold by in-
stalling the bolts.
Tightening torque:
Spark plug:
20 Nm (2.0 m·kgf, 14.5 ft·lbf)
1. Exhaust manifold bolt
1

1. Exhaust manifold
2. Gasket
3. Power reduction plate
Tightening torque:
Exhaust manifold bolt:
8.5 Nm (0.9 m·kgf, 6.1 ft·lbf)
1
23

PERIODIC MAINTENANCE AND MINOR REPAIR
6-7
2
3
4
5
67
8
9

EAU40891
Transmission oil
The transmission oil must be checked
for oil leakage before each ride. If any
leakage is found, have a Yamaha deal-
er check and repair the motorcycle. In
addition, the transmission oil must be
changed at the intervals specified in the
periodic maintenance and lubrication
chart.
1. Place the motorcycle on the cen-
terstand.
2. Place an oil pan under the trans-
mission to collect the used oil.
3. Remove the oil filler cap and drain
bolt to drain the oil from the trans-
mission.4. Install the transmission oil drain
bolt, and then tighten it to the spec-
ified torque.
5. Add the specified amount of the
recommended transmission oil,
and then install and tighten the oil
filler cap.
CAUTION:

ECA10452

In order to prevent clutch slip-
page (since the transmission oil
also lubricates the clutch), do
not mix any chemical additives.
Do not use oils with a diesel
specification of “CD” or oils of a
higher quality than specified. In
addition, do not use oils labeled
“ENERGY CONSERVING II” or
higher.

Make sure that no foreign mate-
rial enters the transmission.
6. Start the engine, and then let it idle
for several minutes while checking
the transmission for oil leakage. If
oil is leaking, immediately turn the
engine off and check for the cause.
1. Transmission oil filler cap
1

1. Transmission oil drain bolt
Tightening torque:
Transmission oil drain bolt:
14 Nm (1.4 m·kgf, 10.1 ft·lbf)
Recommended transmission oil:
See page 8-1.
Oil change quantity:
0.30 L (0.32 US qt) (0.26 Imp.qt)
1