2003 YAMAHA AEROX50 engine

PERIODIC MAINTENANCE AND MINOR REPAIR
6
EAU03453
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.
EW000060
If you are not familiar with scooter
maintenance work, have a Yamaha
dealer do it for you.
EAU00466
EW000061
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.WARNING
WARNING
6-1

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• Check starter (chocke) operation.
√√√√√ √
• 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
6-3

PERIODIC MAINTENANCE AND MINOR REPAIR
6
EAU01651
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.
If the spark plug shows signs of
electrode erosion and excessive carbon
or other deposits, it should be replaced.Specified spark plug:
BR8HS (NGK)
Before installing a spark plug, the spark
plug gap should be measured with a
wire thickness gauge and, if necessary,
adjusted to specification.
Spark plug gap:
0.5 — 0.7 mm
Clean the surface of the spark plug
gasket and its mating surface, and then
wipe off any grime from the spark plug
threads.
a
ZAUM0037
a Spark plug gap
Tightening torque:
Spark plug:
20 Nm (2.0 m
•kg)
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
specified torque as soon as possible.
6-6

PERIODIC MAINTENANCE AND MINOR REPAIR
6
EWA00062
•Make sure that no foreign
material enters the final trans-
mission case.
•Make sure that no oil gets on
the tire or wheel.
7. Check the final transmission case
for oil leakage. If oil is leaking,
check for the cause.
WARNING
EAU04228
Final transmission oil
The final transmission case must be
checked for oil leakage before each
ride. If any leakage is found, have a
Yamaha dealer check and repair the
scooter. In addition, the final transmis-
sion oil must be changed as follows at
the intervals specified in the periodic
maintenance and lubrication chart.
1. Start the engine, warm it up by
riding the scooter for several mi-
nutes, and then stop the engine.2. Place the scooter on the
centerstand.
3. Place an oil pan under the final
transmission case to collect the
used oil.
4. Remove the oil filler cap and drain
bolt to drain the oil from the final
transmission case.
5. Install the final transmission oil
drain bolt, and then tighten it to
the specified torque.
Tightening torque:
Final transmission oil drain bolt:
18 Nm (1.8 m
•kgf)
6. Add the specified amount of the
recommended final transmission
oil, and then install and tighten the
oil filler cap.
Recommended final transmission
oil:
See page 8-1.
Oil quantity:
0.13 L
12ZAUM0273
1. Final transmission oil drain bolt
2. Oil filler cap
6-7

PERIODIC MAINTENANCE AND MINOR REPAIR
6
EC000080
•If coolant is not available, use
distilled water or soft tap water
instead. Do not use hard water
or salt water since it is harmful
to the engine.
•If water has been used instead
of coolant, replace it with
coolant as soon as possible,
otherwise the engine may not
be sufficiently cooled and the
cooling system will not be
protected against frost and cor-
rosion.
•If water has been added to the
coolant, have a Yamaha dealer
check the antifreeze content of
the coolant as soon as possi-
ble, otherwise the effectiveness
of the coolant will be reduced.
EW000067
Never attempt to remove the radiator
cap when the engine is hot.
CAUTION:
WARNING
EAU01808*
Coolant
To check the coolant level
1. Place the scooter on a level sur-
face and hold it in an upright po-
sition.
NOTE :
•The coolant level must be
checked on a cold engine since
the level varies with engine
temperature.
•Make sure that the scooter is
positioned straight up when
checking the coolant level. A slight
tilt to the side can result in a false
reading.
2. Remove cowling A. (See page
6-5 for cowling removal and ins-
tallation procedures.)3. Check the coolant level in the
coolant reservoir.
NOTE :
The coolant should be between the
minimum and maximum level marks.
4. If the coolant is at or below the
minimum level mark, open the
reservoir cap, add coolant to the
maximum level mark, and then
close the reservoir cap.
Coolant reservoir capacity:
0.25 L

1
ZAUM0274
1. Coolant tank cap
6-8

PERIODIC MAINTENANCE AND MINOR REPAIR
6
1
ZAUM0276
1. Air filter element
5. Install the cowling.
NOTE :
If the engine overheats, see page 6-24
for further instructions.
1
ZAUM0275
1. Screws
EAUM0071
Cleaning the air filter
element
The air filter element should be cleaned
at the intervals specified in the periodic
maintenance and lubrication chart.
Clean the air filter element more
frequently if you are riding in unusually
wet or dusty areas.
1. Remove the air filter case cover
by removing the screws.2. Pull the air filter element out, clean
it with solvent, and then squeeze
the remaining solvent out.
EW000075
Use only a dedicated parts cleaning
solvent. To avoid the risk of fire or
explosion, do not use gasoline or
solvents with a low flash point.
EC000089
To avoid damaging the foam material,
handle it gently and carefully, and do
not twist or wring it.
WARNING
CAUTION:
6-9

PERIODIC MAINTENANCE AND MINOR REPAIR
6
1
4 32
ZAUM0156
3. Apply oil of the recommended
type to the entire surface of the
element, and then squeeze the
excess oil out.
NOTE :
The air filter element should be wet but
not dripping.
Recommended oil:
Engine oil
4. Insert the element into the air filter
case.
CAUTION:EC000082
•Make sure that the air filter
element is properly seated in
the air filter case.
•The engine should never be
operated without the air filter
element installed, otherwise the
piston(s) and/or cylinder(s) may
become excessively worn.
5. Install the air filter case cover by
installing the screws.
6-10
EAU00631
Adjusting the carburetor
The carburetor is an important part of
the engine and requires very
sophisticated adjustment. Therefore, all
carburetor adjustments should be left
to a Yamaha dealer, who has the
necessary professional knowledge and
experience.

PERIODIC MAINTENANCE AND MINOR REPAIR
6Observe these precautions:
•When checking the fluid level,
make sure that the top of the
master cylinder is level by turning
the handlebars.
•Use only the recommended
quality brake fluid, otherwise the
rubber seals may deteriorate,
causing leakage and poor braking
performance.
Recommended brake fluid:
DOT 4
NOTE :
If DOT 4 is not available, DOT 3 can be
used.
•Refill with the same type of brake
fluid. Mixing fluids may result in a
harmful chemical reaction and
lead to poor braking performance.
•Be careful that water does not
enter the master cylinder when
refilling. Water will significantly
lower the boiling point of the fluid
and may result in vapor lock.
•Brake fluid may deteriorate
painted surfaces or plastic parts.
Always clean up spilled fluid
immediately.
•As the brake pads wear, it is nor-
mal for the brake fluid level to
gradually go down. However, if the
brake fluid level goes down
suddenly, have a Yamaha dealer
check the cause.
EAUM0008*
Changing the brake fluid
Have a Yamaha dealer change the
brake fluid at the intervals specified in
the periodic maintenance and
lubrication chart. In addition, have the
brake hoses replaced every four years
or whenever there are damaged or
leaking.
6-15
EAU00774
Adjusting the Autolube pump
The Autolube pump is a vital and
sophisticated component of the engine,
which must be adjusted by a Yamaha
dealer at the intervals specified in the
periodic maintenance and lubrication
chart.