2003 YAMAHA AEROX50 engine

PERIODIC MAINTENANCE AND MINOR REPAIR
6
ZAUM0061
EAU03118
Lubricating the front and rear
brake levers
The pivoting points of the front and rear
brake levers must be lubricated at the
intervals specified in the periodic main-
tenance and lubrication chart.
Recommended lubricant:
Lithium-soap-based grease
(all-purpose grease)
ZAUM0062
EAU04123
Checking and lubricating the
centerstand
The operation of the centerstand should
be checked before each ride, and the
pivots and metal-to-metal contact sur-
faces should be lubricated if necessary.
EWA00055
If the centerstand does not move up
and down smoothly, have a Yamaha
dealer check or repair it.
Recommended lubricant:
Lithium-soap-based grease
(all-purpose grease)
WARNING
6-16
EAU02962
Checking and lubricating the
cables
The operation of all control cables and
the condition of the cables should be
checked before each ride, and the cables
and cable ends should be lubricated if
necessary. If a cable is damaged or does
not move smoothly, have a Yamaha dea-
ler check or replace it.
Recommended lubricant:
Engine oil
EW000112
Damage to the outer sheath may
interfere with proper cable operation
and will cause the inner cable to rust.
Replace a damaged cable as soon
as possible to prevent unsafe con-
ditions.
WARNING

PERIODIC MAINTENANCE AND MINOR REPAIR
6
EAU02939
Checking the front fork
The condition and operation of the front
fork must be checked as follows at the
intervals specified in the periodic main-
tenance and lubrication chart.
To check the condition
EW000115
Securely support the scooter so that
there is no danger of it falling over.
Check the inner tubes for scratches,
damage and excessive oil leakage.
WARNINGTo check the operation
1. Place the scooter on a level sur-
face and hold it in an upright po-
sition.
2. While applying the front brake,
push down hard on the
handlebars several times to check
if the front fork compresses and
rebounds smoothly.
EC000098
If any damage is found or the front
fork does not operate smoothly, have
a Yamaha dealer check or repair it.
CAUTION:
EAU00794
Checking the steering
Worn or loose steering bearings may
cause danger. Therefore, the operation
of the steering must be checked as
follows at the intervals specified in the
periodic maintenance and lubrication
chart.
1. Place a stand under the engine
to raise the front wheel off the
ground.
EW000115
Securely support the scooter so that
there is no danger of it falling over.
WARNING
6-17
ZAUM0296ZAUM0297

PERIODIC MAINTENANCE AND MINOR REPAIR
6
EAU03363
Troubleshooting charts
Starting problems or poor engine performance
EW000125
Keep away open flames and do not smoke while checking or working on the fuel system.
WARNING
Check the fuel level in
the fuel tank.
1. FuelThere is enough fuel.
There is no fuel.Check the compression.
Supply fuel.
Operate the electric starter.
2. CompressionThere is compression.
There is no compression.Check the ignition.
Have a Yamaha dealer
check the vehicle.
Remove the spark plugs
and check the electrodes.
3. IgnitionWet
DryWipe off with a dry cloth and correct the
spark plug gaps, or replace the spark plugs.
Have a Yamaha dealer check the vehicle.The engine does not start.
Check the battery.Open the throttle halfway and operate
the electric starter.
Operate the electric starter.
4. BatteryThe engine turns over
quickly.
The engine turns over
slowly.The battery is good.
Check the electrolyte and battery
lead connections, and charge the
battery if necessary.The engine does not start.
Have a Yamaha dealer
check the vehicle.
The engine does not start.
Check the compressoin.
6-23

PERIODIC MAINTENANCE AND MINOR REPAIR
6 Engine overheating
EW000070
•Do not remove the radiator cap when the engine and radiator are hot. Scalding hot fluid and steam may be
blown out under pressure, which could cause serious injury. Be sure to wait until the engine has cooled.
•After removing the radiator cap retaining bolt, place a thick rag, like a towel, over the radiator cap, and then
slowly rotate the cap counterclockwise to the detent to allow any residual pressure to escape. When the hissing
sound has stopped, press down on the cap while turning it counterclockwise, and then remove the cap.
NOTE :
If coolant is not available, tap water can be temporarily used instead, provided that it is changed to the recommended
coolant as soon as possible.
WARNING
Wait until the
engine has cooled.Check the coolant level in the
reservoir and radiator.
The coolant level
is OK.
The coolant level is low.
Check the cooling system
for leakage.
Have a Yamaha dealer checkand repair the cooling system.
Add coolant. (See NOTE.)
Start the engine. If the engine overheats again, have a
Yamaha dealer check and repair the cooling system.
There is
leakage.
There is
no leakage.
6-24

SCOOTER CARE AND STORAGE
7
Care
While the open design of a scooter
reveals the attractiveness of the
technology, it also makes it more
vulnerable. Rust and corrosion can
develop even if high-quality
components are used. A rusty exhaust
pipe may go unnoticed on a car,
however, it detracts from the overall
appearance of a scooter. Frequent and
proper care does not only comply with
the terms of the warranty, but it will also
keep your scooter looking good, extend
its life and optimize its performance.Before cleaning
1. Cover the muffler outlet with a
plastic bag after the engine has
cooled down.
2. Make sure that all caps and covers
as well as all electrical couplers
and connectors, including the
spark plug cap, are tightly
installed.
3. Remove extremely stubborn dirt,
like oil burnt onto the crankcase,
with a degreasing agent and a
brush, but never apply such
products onto seals, gaskets and
wheel axles. Always rinse the dirt
and degreaser off with water.CleaningECA00011
•Avoid using strong acidic wheel
cleaners, especially on spoked
wheels. If such products are
used on hard-to-remove dirt, do
not leave the cleaner on the
affected area any longer than
instructed. Also, thoroughly
rinse the area off with water,
immediately dry it, and then
apply a corrosion protection
spray.
•Improper cleaning can damage
windshields, cowlings, panels
and other plastic parts. Use
only a soft, clean cloth or
sponge with mild detergent and
water to clean plastic.
CAUTION:
7-1

SCOOTER CARE AND STORAGE
7
•Do not use any harsh chemical
products on plastic parts. Be
sure to avoid using cloths or
sponges which have been in
contact with strong or abrasive
cleaning products, solvent or
thinner, fuel (gasoline), rust
removers or inhibitors, brake
fluid, antifreeze or electrolyte.
•Do not use high-pressure
washers or steam-jet cleaners
since they cause water
seepage and deterioration in
the following areas: seals (of
wheel and swingarm bearings,
fork and brakes), electric
components (couplers,
connectors, instruments,
switches and lights), breather
hoses and vents.
•For scooters equipped with a
windshield: Do not use strong
cleaners or hard sponges as
they will cause dulling or
scratching. Some cleaning
compounds for plastic may
leave scratches on the
windshield. Test the product on
a small hidden part of the
windshield to make sure that it
does not leave any marks. If the
windshield is scratched, use a
quality plastic polishing
compound after washing.
After normal use
Remove dirt with warm water, a mild
detergent, and a soft, clean sponge,
and then rinse thoroughly with clean
water. Use a toothbrush or bottlebrush
for hard-to-reach areas. Stubborn dirt
and insects will come off more easily if
the area is covered with a wet cloth for
a few minutes before cleaning.
After riding in the rain, near the sea
or on salt-sprayed roads
Since sea salt or salt sprayed on the
roads during winter are extremely cor-
rosive in combination with water, carry
out the following steps after each ride
in the rain, near the sea or on salt-
sprayed roads.
NOTE :
Salt sprayed on roads in the winter may
remain well into spring.
1. Clean the scooter with cold water
and a mild detergent after the
engine has cooled down.
ECA00012
Do not use warm water since it
increases the corrosive action of the
salt.
2. Apply a corrosion protection spray
on all metal, including chrome-
and nickel-plated, surfaces to
prevent corrosion.
CAUTION:
7-2

SCOOTER CARE AND STORAGE
7 Long-term
Before storing your scooter for several
months:
1. Follow all the instructions in the
"Care" section of this chapter.
2. Drain the carburetor float chamber
by loosening the drain bolt; this will
prevent fuel deposits from building
up. Pour the drained fuel into the fuel
tank.
3. Fill up the fuel tank and add fuel
stabilizer (if available) to prevent the
fuel tank from rusting and the fuel
from deteriorating.
4. Perform the following steps to protect
the cylinder, piston rings, etc. from
corrosion.
a. Remove the spark plug cap
and spark plug.
b. Pour a teaspoonful of engine oil
into the spark plug bore.c. Install the spark plug cap onto
the spark plug, and then place
the spark plug on the cylinder
head so that the electrodes are
grounded. (This will limit
sparking during the next step.)
d. Turn the engine over several
times with the starter. (This will
coat the cylinder wall with oil.)
e. Remove the spark plug cap
from the spark plug, and then
install the spark plug and the
spark plug cap.
EWA00003
To prevent damage or injury from
sparking, make sure to ground the
spark plug electrodes while turning
the engine over.
5. Lubricate all control cables and
the pivoting points of all levers and
pedals as well as of the sidestand/
centerstand.6. Check and, if necessary, correct
the tire air pressure, and then lift
the scooter so that both of its
wheels are off the ground.
Alternatively, turn the wheels a
little every month in order to
prevent the tires from becoming
degraded in one spot.
7. Cover the muffler outlet with a
plastic bag to prevent moisture
from entering it.
8. Remove the battery and fully
charge it. Store it in a cool, dry
place and charge it once a month.
Do not store the battery in an
excessively cold or warm place
(less than 0 °C or more than 30
°C). For more information on
storing the battery, see page 6-19.
NOTE :
Make any necessary repairs before
storing the scooter.
WARNING
7-4

SPECIFICATIONS
8
Specifications
Model YQ50
Dimensions:
Overall length 1.743 mm
Overall width 690 mm
Overall height 1.170 mm
Seat height 828 mm
Wheelbase 1.256 mm
Minimum ground clearance 185 mm
Minimum turning radius 1.800 mm
Basic weight:97 kg
(with oil and full fuel tank)
Engine:
Engine type Liquid cooled, 2 stroke
Cylinder arrangement Single cylinder, horizontal
Displacement 49.2 cc
Bore x stroke 40.0 x 39.2
Compression ratio 7.44:1
Starting system Electric and kick starter
Lubrication systemSeparate lubrication (Autolube)
Engine oil:
Type Yamalube 2
or 2 stroke engine oil
Recommended engine oil Jaso FC
classification or ISO EG-C, EG-D
Capacity 1.3 LFinal transmission oil:
Type SAE 10W30 type SE
Quantity 0.13L
Cooling system capacity:1.2L
(total amount)
Air filter type:Wet type element
Fuel:
Recommended fuel Regular unleaded gasoline
(RON 91 mini)
Fuel tank capacity 7L
Carburetor:
Manufacturer DELL'ORTO
Model/quantity PHBN 12HS x1
Spark plug:
Manufacturer/Model NGK / BR8HS
Spark plug gap 0.5—0.7 mm
Clutch type:Dry, centrifugal automatic
Transmission:
Primary reduction system Helical gear
Primary reduction ratio 52/13 (4.000)
Secondary reduction system Spur gear
Secondary reduction ratio 43/14 (3.071)
Transmission type V-belt automatic
Operation Centrifugal automatic type
8-1