2003 YAMAHA WHY 50 engine

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OPERATION AND IMPORTANT RIDING POINTS
Starting the engine .............................................................................. 5-1
Starting off ........................................................................................... 5-2
Acceleration and deceleration ............................................................. 5-2
Braking ................................................................................................ 5-3
Tips for reducing fuel consumption ..................................................... 5-3
Engine break-in ................................................................................... 5-4
Parking ................................................................................................ 5-4
5

OPERATION AND IMPORTANT RIDING POINTS
5
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•Become thoroughly familiar
with all operating controls and
their functions before riding.
Consult a Yamaha dealer
regarding any control or
function that you do not
thoroughly understand.
•Never start the engine or
operate it in a closed area for
any length of time. Exhaust fu-
mes are poisonous, and
inhaling them can cause loss of
consciousness and death
within a short time. Always
make sure that there is
adequate ventilation.
•For safety, always start the
engine with the centerstand
down.
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Starting the engineEC000046
See page 5-4 for engine break-in ins-
tructions prior to operating the
vehicle for the first time.
1. Turn the key to "
", and when the
oil level warning light comes on,
turn it to "
".EC000045
If the oil level warning light does not
come on, have a Yamaha dealer
check the electrical circuit.
2. Close the throttle completely.3. While applying the front or rear
brake, start the engine by pushing
the start switch or by pushing the
kickstarter lever down.
NOTE :
If the engine fails to start by pushing
the start switch, release the switch, wait
a few seconds, and then try again. Each
starting attempt should be as short as
possible to preserve the battery. Do not
crank the engine more than 5 seconds
on any one attempt. If the engine does
not start with the starter motor, try using
the kickstarter.
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PUSH
OPEN
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5-1

OPERATION AND IMPORTANT RIDING POINTS
5
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Starting off
NOTE :
Before starting off, allow the engine to
warm up.
1. While pulling the rear brake lever
with your left hand and holding the
carrier with your right hand, push
the scooter off the centerstand.
2. Sit astride the seat, and then
adjust the rear view mirrors.
3. Switch the turn signal on.
4. Check for oncoming traffic, and
then slowly turn the throttle grip
(on the right) in order to take off.
5. Switch the turn signal off.
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For maximum engine life, never
accelerate hard when the engine is
cold!
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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
throttle grip in direction b .
5-2

OPERATION AND IMPORTANT RIDING POINTS
5
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Braking
1. Close the throttle completely.
2. Apply both front and rear brakes
simultaneously while gradually
increasing the pressure.
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•Avoid braking hard or suddenly
(especially when leaning over
to one side), otherwise the
scooter may skid or overturn.
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•Railroad crossings, streetcar
rails, iron plates on road cons-
truction sites, and manhole
covers become extremely
slippery when wet. Therefore,
slow down when approaching
such areas and cross them with
caution.
•Keep in mind that braking on a
wet road is much more difficult.
Ride slowly down a hill, as
braking downhill can be very
difficult.
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Tips for reducing fuel
consumption
Fuel consumption depends largely on
your riding style. Consider the following
tips to reduce fuel consumption:
•Thoroughly warm up the engine.
Avoid high engine speeds during
acceleration.
•Avoid high engine speeds with no
load on the engine.
•Turn the engine off instead of
letting it idle for an extended length
of time (e.g., in traffic jams, at
traffic lights or at railroad
crossings).
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OPERATION AND IMPORTANT RIDING POINTS
5
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Engine break-in
There is never a more important period
in the life of your engine than the period
between 0 and 1,000 km. For this
reason, you should read the following
material carefully.
Since the engine is brand new, do not
put an excessive load on it for the first
1,000 km. The various parts in the
engine wear and polish themselves to
the correct operating clearances.
During this period, prolonged full-
throttle operation or any condition that
might result in engine overheating must
be avoided.
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0 — 150 km
Avoid operation above 1/3 throttle. Stop
the engine and let it cool for 5 to 10
minutes after every hour of operation.
Vary the speed of the scooter from time
to time. Do not operate it at one set
throttle position.150 — 500 km
Avoid prolonged operation above 1/2
throttle.
500 — 1,000 km
Avoid cruising speeds in excess of 3/
4 throttle.
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After 1,000 km of operation, be sure
to replace the final transmission oil.
1,000 km and beyond
Avoid prolonged full throttle operation.
Vary speeds occasionally.
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If any engine trouble should occur
during the engine break-in period,
immediately have a Yamaha dealer
check the vehicle.
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Parking
When parking, stop the engine, and
then remove the key from the main
switch.
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•Since the engine and exhaust
system can become very hot,
park in a place where
pedestrians or children are not
likely to touch them.
•Do not park on a slope or on
soft ground, otherwise the
scooter may overturn.
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Never park in an area where there
are fire hazards such as grass or
other flammable materials.
5-4

PERIODIC MAINTENANCE AND MINOR REPAIR
6
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Safety is an obligation of the owner.
Periodic inspection, adjustment and
lubrication will keep your vehicle in the
safest and most efficient condition pos-
sible. The most important points of
scooter inspection, adjustment, and
lubrication are explained on the
following pages.
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If you are not familiar with scooter
maintenance work, have a Yamaha
dealer do it for you.
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This scooter is designed for use on
paved roads only. If this scooter is
operated in abnormally dusty,
muddy or wet conditions, the air filter
element should be cleaned or
replaced more frequently, otherwise
rapid engine wear may result.
Consult a Yamaha dealer for proper
maintenance intervals.
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PERIODIC MAINTENANCE AND MINOR REPAIR
6
•Check tread depth and for damage.
9 * Tires•Replace if necessary.
√√√√ √
•Check air pressure.
•Correct if necessary.
10 * Wheel bearings•Check bearing for looseness or damage.√√√√
11 * Steering bearings•Check bearing play and steering for roughness.√√√√√•Lubricate with lithium-soap-based grease. Every 24,000 km
12 * Chassis fasteners•Make sure that all nuts, bolts and screws are
√√√√ √
properly tightened.
13 Centerstand•Check operation.
√√√√ √
•Lubricate.
14 * Front fork•Check operation and for oil leakage.√√√√
15 * Shock absorber assembly•Check operation and shock absorber for oil leakage.√√√√
16 * Carburetor•Adjust engine idling speed.√√√√√ √
17 * Autolube pump•Check operation.
√√√√
•Bleed if necessary.
18 Final transmission oil•Check vehicle for oil leakage.√√ √•Change.√√√
19 * V-belt•Replace. Every 10,000 km
20 * Front and rear brake
•Check operation.√√√√√ √
switches
ODOMETER READING (x 1,000 km)
NO. ITEMCHECK OR MAINTENANCE JOB
1
ANNUAL
CHECK
6121824
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PERIODIC MAINTENANCE AND MINOR REPAIR
6
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Removing and installing the
panel
The panel shown above needs to be
removed to perform some of the main-
tenance jobs described in this chapter.
Refer to this section each time the pa-
nel needs to be removed and installed.
1
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1. Panel A
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Checking the spark plug
The spark plug is an important engine
component, which should be checked
periodically, preferably by a Yamaha
dealer. Since heat and deposits will
cause any spark plug to slowly erode,
it should be removed and checked in
accordance with the periodic mainte-
nance and lubrication chart. In addition,
the condition of the spark plug can
reveal the condition of the engine.
The porcelain insulator around the
center electrode of the spark plug
should be a medium-to-light tan (the
ideal color when the scooter is ridden
normally). If the spark plug shows a
distinctly different color, the engine
could be defective. Do not attempt to
diagnose such problems yourself.
Instead, have a Yamaha dealer check
the scooter.
6-5
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Panel A
To remove the panel
1. Open the seat. (See page 3-8 for
seat opening and closing
procedures.)
2. Remove the panel by pulling it up
as shown.
To install the panel
1. Insert the rear of the panel in the
original position, and then push
the front of the panel inward..
2. Close the seat.