2003 YAMAHA AEROX50 engine

3
INSTRUMENT AND CONTROL FUNCTIONS
EAU03091
Rider seat
To open the rider seat
1. Place the scooter on the
centerstand.
2. Insert the key into the main switch,
and then turn it counterclockwise.
NOTE :
Do not push inward when turning the
key.
3. Fold the rider seat up.To close the rider seat
1. Fold the rider seat down, and then
push it down to lock it in place.
2. Remove the key from the main
switch if the scooter will be left
unattended.
NOTE :
Make sure that the seat is properly
secured before riding.
1
ZAUM0264
1. Seat
3-9
EAU03839
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).
1. Starter (choke) lever ""
a
b
1
ZAUM0293

PRE-OPERATION CHECKS
4
EAU03439
Pre-operation check list
ITEM CHECKS PAGE
• Check fuel level in fuel tank.
Fuel• Refuel if necessary. 3-5 — 3-6
• Check fuel line for leakage.
• Check oil level in oil tank.
Two-stroke engine oil• If necessary, add recommended oil to specified level. 3-8, 6-15
• Check vehicle for oil leakage.
Final transmission oil• Check vehicle for oil leakage. 6-7
• Check coolant level in reservoir.
Coolant• If necessary, add recommended coolant to specified level. 6-8
• Check cooling system for leakage.
• Check operation.
• If soft or spongy, have Yamaha dealer bleed hydraulic system.
Front brake• Check fluid level in reservoir. 3-5, 6-13 — 6-15
• If necessary, add recommended brake fluid to specified level.
• Check hydraulic system for leakage.
• Check operation.
• If soft or spongy, have Yamaha dealer bleed hydraulic system.
Rear brake• Check fluid level in reservoir. 3-5, 6-13 — 6-15
• If necessary, add recommended brake fluid to specified level.
• Check hydraulic system for leakage.
The condition of a vehicle is the owner’s responsibility. Vital components can start to deteriorate quickly and unexpectedly,
even if the vehicle remains unused (for example, as a result of exposure to the elements). Any damage, fluid leakage or
loss of tire air pressure could have serious consequences. Therefore, it is very important, in addition to a thorough visual
inspection, to check the following points before each ride.
4-1

EAU00372
OPERATION AND IMPORTANT RIDING POINTS
Starting the engine .............................................................................. 5-1
Starting a warm engine ....................................................................... 5-2
Starting off ........................................................................................... 5-2
Acceleration and deceleration ............................................................. 5-3
Braking ................................................................................................ 5-3
Tips for reducing fuel consumption ..................................................... 5-4
Engine break-in ................................................................................... 5-4
Parking ................................................................................................ 5-5
5

OPERATION AND IMPORTANT RIDING POINTS
5
EAU01118
EW000129
•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.
WARNING
CAUTION:
CAUTION:
PUSH
OPEN
ZAUM0253
5-1
EAU00415*
Starting the engine
1. Turn the key to "", then 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. Turn the starter (choke) on and
completely close the throttle. (See
page 3-9 for starter (choke)
operation.)3. Start the engine by pushing the
start switch or by pushing the
kickstarter lever down, while
applying the front or rear brake.
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.
4. After starting the engine, move the
starter (choke) lever back halfway.
ECA00045
For maximum engine life, never
accelerate hard when the engine is
cold!

OPERATION AND IMPORTANT RIDING POINTS
5
EAU00433
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
grab bar 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.
ZAUM0267
5-2
5. When the engine is warm, turn the
starter (choke) off.
NOTE :
The engine is warm when it responds
normally to the throttle with the starter
(choke) turned off.
EAU01258
Starting a warm engine
Follow the same procedure as for
starting a cold engine with the excep-
tion that the starter (choke) is not
required when the engine is warm.

OPERATION AND IMPORTANT RIDING POINTS
5
EAU00436
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.
EAUT0003
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.
ECAT0001
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.
EC000049
If any engine trouble should occur
during the engine break-in period,
immediately have a Yamaha dealer
check the vehicle.
CAUTION:
CAUTION:
5-4
EAU03093
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).

OPERATION AND IMPORTANT RIDING POINTS
5
EAU00461
Parking
When parking, stop the engine, and
then remove the key from the main
switch.
EW000058
•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.
EC000062
Never park in an area where there
are fire hazards such as grass or
other flammable materials.
WARNING
CAUTION:
5-5

EAU00462
PERIODIC MAINTENANCE AND MINOR REPAIR
Periodic maintenance and lubrication chart ............ 6-2
Removing and installing cowling and panel ............ 6-5
Cowling A ................................................................ 6-5
Panel A .................................................................... 6-5
Checking the spark plug ......................................... 6-6
Final transmission oil .............................................. 6-7
Coolant .................................................................... 6-8
Cleaning the air filter element ................................. 6-9
Adjusting the carburetor ........................................ 6-10
Adjusting the throttle cable free play ..................... 6-11
Tires ...................................................................... 6-11
Wheels .................................................................. 6-13
Adjusting the front and rear brake lever
free play ................................................................ 6-13
Checking the front and rear brake pads ................ 6-14
Checking the brake fluid level ............................... 6-14
6 Changing the brake fluid ....................................... 6-15
Adjusting the autolube pump ................................ 6-15
Checking and lubricating the cables ..................... 6-16
Lubricating the front and rear brakes levers .......... 6-16
Checking and lubricating the centerstand ............. 6-16
Checking the front fork .......................................... 6-17
Checking the steering ........................................... 6-17
Checking the wheel bearings ................................ 6-18
Battery ................................................................... 6-18
Replacing the fuse ................................................ 6-20
Replacing a headlight bulb .................................... 6-20
Replacing tail/brake light bulb ............................... 6-21
Replacing a turn signal light bulb .......................... 6-22
Troubleshooting ..................................................... 6-22
Troubleshooting chart ............................................ 6-23
Engine overheating ............................................... 6-24