Page 14 of 80
2
DESCRIPTION
Left view
6
5 7
1234
1. Rear brake lever (page 3-5, 6-12, 6-15)
2. Fuel gauge (page 3-3)
3. Speedometer (page 3-3)
4. Main switch (page 3-1, 3-8)5. Final transmission oil filler cap (page 6-6)
6. Kick starter (page 3-7)
7. Air filter (page 6-7)
2-1
Page 37 of 80

EAU00462
PERIODIC MAINTENANCE AND MINOR REPAIR
Periodic maintenance and lubrication chart ............ 6-2
Removing and installing the panel .......................... 6-5
Panel A .................................................................... 6-5
Checking the spark plug ......................................... 6-5
Final transmission oil .............................................. 6-6
Cleaning the air filter element ................................. 6-7
Adjusting the carburetor .......................................... 6-9
Adjusting the throttle cable free play ....................... 6-9
Tires ...................................................................... 6-10
Cast wheels .......................................................... 6-11
Adjusting the front brake lever free play ................ 6-12
Adjusting the front brake lever free play ................ 6-12
Checking the front brake pads .............................. 6-13
and rear brake shoes
Checking the brake fluid level ............................... 6-14
6 Changing the brake fluid ....................................... 6-15
Checking and lubricating the throttle grip .............. 6-15
and cable
Lubricating the front and rear brakes levers .......... 6-15
Checking and lubricating the centerstand ............. 6-16
Checking the front fork .......................................... 6-16
Checking the steering ........................................... 6-17
Checking the wheel bearings ................................ 6-17
Battery ................................................................... 6-18
Replacing the fuse ................................................ 6-19
Replacing a headlight bulb .................................... 6-20
Replacing the brake taillight bulb .......................... 6-21
Replacing a turn signal light bulb .......................... 6-21
Troubleshooting ..................................................... 6-22
Troubleshooting chart ............................................ 6-23
Page 38 of 80
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.
6-1
Page 39 of 80

PERIODIC MAINTENANCE AND MINOR REPAIR
6
1 * Fuel line•Check fuel hoses and vacuum hose for cracks or damage.√√√√ √
2 Spark plug•Replace.√√√√ √
3 Air filter element•Clean.√√•Replace.√√
4 * Battery•Check electrolyte level and specific gravity.
√√√√ √
•Make sure that the breather hose is properly routed.
•Check operation, fluid level and vehicle for fluid leak
√√√√√ √
5 * Front brake(See NOTE on page 6-4.)
•Replace brake pads. Whenever worn to the limit
6 * Rear brake•Check operation and adjust brake lever free play.√√√√√ √•Replace brake shoes. Whenever worn to the limit
7 * Brake hose•Check for cracks or damage.√√√√ √•Replace. (See NOTE on page 6-4.) Every 4 years
8 * Wheels•Check runout and for damage.√√√√
EAU03686
Periodic maintenance and lubrication chart
NOTE :
•The annual checks must be performed every year, except if a kilometer-based maintenance is performed instead.
•From 30,000 km, repeat the maintenance intervals starting from 6,000 km.
•Items marked with an asterisk should be performed by a Yamaha dealer as they require special tools, data and technical skills.
ODOMETER READING (x 1,000 km)
NO. ITEMCHECK OR MAINTENANCE JOB
1
ANNUAL
CHECK
6121824
6-2
Page 41 of 80
PERIODIC MAINTENANCE AND MINOR REPAIR
6
21 Moving parts and cables•Lubricate.√√√√ √
22 * Lights, signals and•Check operation.
√√√√√ √
switches•Adjust headlight beam.
ODOMETER READING (x 1,000 km)
NO. ITEMCHECK OR MAINTENANCE JOB
1
ANNUAL
CHECK
6121824
EAU03541*
NOTE :
•The air filter needs more frequent service if you are riding in unusually wet or dusty areas.
•Hydraulic brake service
•Regularly check and, if necessary, correct the brake fluid level.
•Every two years change the brake fluid.
•Replace the brake hoses every four years and if cracked or damaged.
6-4
Page 44 of 80

PERIODIC MAINTENANCE AND MINOR REPAIR
64. 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:
17 Nm (1.7 m
•kg)
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:
0.11 L
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.
1
2
ZAUM0371
1. Oil filler cap
2. Oil drain bolt
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.
1
ZAUM0372
1. Screws
6-7
Page 45 of 80

PERIODIC MAINTENANCE AND MINOR REPAIR
6 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.
1
ZAUM0373
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.
1. Air filter element
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.
6-8
Page 68 of 80

SPECIFICATIONS
8
Model YH50
Dimensions:
Overall length 1.940 mm
Overall width 685 mm
Overall height 1.105 mm
Seat height 765 mm
Wheelbase 1.294 mm
Minimum ground clearance 125 mm
Minimum turning radius 1.800 mm
Weight:
Wet (with oil and a full fuel tank) 78 kg
Engine:
Engine type Air cooled, 2 strokes
Cylinder arrangement Single cylinder, horizontal
Displacement 49.2 cm3
Bore x stroke 40.0 x 39.2
Compression ratio 7.25:1
Starting system type Electric and kick starter
Lubrication system Separate lubrication
(Autolube)
Engine oil:
Type Yamalube 2
or 2 strokes engine oil
Classification Jaso FC ou ISO EG-C, EG-D
Capacity 1.3 LTransmission oil:
Type SAE 10W30 type SE
Capacity
Périodic oil change 0.11L
Total amount 0.13L
Air filter type:Wet type element
Fuel:
Recommended fuel Regular unleaded gasoline
(RON 91 mini)
Fuel tank capacity 7L
Carburetor:
Type / quantity PY-12
Manufacturer GURTNER
Spark plug:
Type / Manufacturer BR8HS / NGK
Spark plug gap 0.6—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 45/12 (3.750)
Transmission type V-belt automatic
Operation Centrifugal automatic type
8-1
Specifications