2003 YAMAHA WHY 50 brake pads

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

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

PERIODIC MAINTENANCE AND MINOR REPAIR
6
EAU00720
Checking the front brake
pads and rear brake shoes
The front brake pads and the rear brake
shoes must be checked for wear at the
intervals specified in the periodic main-
tenance and lubrication chart.
EAU01436
Front brake pads
Check each front brake pad for damage
and measure the lining thickness. If a
brake pad is damaged or if the lining
thickness is less than 0.5 mm, have a
Yamaha dealer replace the brake pads
as a set.
EAU04502
Rear brake shoes
The rear brake is provided with a wear
indicator, which allows you to check the
brake shoe wear without having to
disassemble the brake. To check the
brake shoe wear, check the position of
the wear indicator while applying the
brake. If a brake shoe has worn to the
point that the wear indicator reaches
the wear limit line, have a Yamaha dea-
ler replace the brake shoes as a set.
a
ZAUM0375ZAUM0376
1
2
1. Wear indicator
2. Wear limit a Lining thickness
6-13

PERIODIC MAINTENANCE AND MINOR REPAIR
6
EAU00732
Checking the brake fluid
level
Insufficient brake fluid may allow air to
enter the brake system, possibly
causing it to become ineffective.
Before riding, check that the brake fluid
is above the minimum level mark and
replenish if necessary. A low brake fluid
level may indicate worn brake pads
and/or brake system leakage. If the
brake level is low, be sure to check the
brake pads for wear and the brake
system for leakage.Observe 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.
1
ZAUM0377
1. Brake fluid level
6-14