2003 YAMAHA YBR125 wheel

VII
TWO-WHEELED MACHINES ARE SINGLE TRACK VEHICLES. THEIR SAFE USE AND OPERATION ARE DEPENDENT
UPON THE USE OF PROPER RIDING TECHNIQUES AS WELL AS THE EXPERTISE OF THE OPERATOR.
EVERY OPERATOR SHOULD KNOW THE FOLLOWING REQUIREMENTS BEFORE RIDING. HE OR SHE SHOULD.
1. OBTAIN THOROUGH INSTRUCTIONS FORM A COMPETENT SOURCE ON ALL ASPECTS OF MACHINE
OPERATION.
2. OBSERVE THE WARNINGS AND MAINTENANCE REQUIREMENTS IN THE OWNER’S MANUAL.
3. OBTAIN QUALIFIED TRAINING IN SAFE AND PROPER RIDING TECHNIQUES.
4. OBTAIN PROFESSIONAL TECHNICAL SERVICE AS INDICATED BY THE OWNER’S MANUAL AND/OR WHEN
MADE NECESSARY BY MECHANICAL CONDITIONS.
SAFE RIDING
1. Always make pre-operation checks. Careful checks may help prevent an accident.
2. Many accidents involve inexperienced operators.
a. Know your skills and limits. Staying within your limits may help you to avoid an accident.
b. Only lend your machine to experienced operators.
3. Many machine accidents have been caused by machine operator errors. A typical error made by the operator is veering
wide on a turn due to EXCESSIVE SPEED or undercornering (insufficient lean angle for the speed). Never travel faster
than warranted by conditions.
4. Ride cautiously in unfamiliar areas. You may encounter hidden obstacles which could cause an accident.
5. The operator’s posture is important for proper control. The operator should keep both hands on the handlebars and
both feet on the operator footrests during operation to maintain control of the machine.
6. Never ride under the influence of alcohol or drugs.
SAFETY INFORMATION
VII
TWO-WHEELED MACHINES ARE SINGLE TRACK VEHICLES. THEIR SAFE USE AND OPERATION ARE DEPENDENT
UPON THE USE OF PROPER RIDING TECHNIQUES AS WELL AS THE EXPERTISE OF THE OPERATOR.
EVERY OPERATOR SHOULD KNOW THE FOLLOWING REQUIREMENTS BEFORE RIDING. HE OR SHE SHOULD.
1. OBTAIN THOROUGH INSTRUCTIONS FORM A COMPETENT SOURCE ON ALL ASPECTS OF MACHINE
OPERATION.
2. OBSERVE THE WARNINGS AND MAINTENANCE REQUIREMENTS IN THE OWNER’S MANUAL.
3. OBTAIN QUALIFIED TRAINING IN SAFE AND PROPER RIDING TECHNIQUES.
4. OBTAIN PROFESSIONAL TECHNICAL SERVICE AS INDICATED BY THE OWNER’S MANUAL AND/OR WHEN
MADE NECESSARY BY MECHANICAL CONDITIONS.
SAFE RIDING
1. Always make pre-operation checks. Careful checks may help prevent an accident.
2. Many accidents involve inexperienced operators.
a. Know your skills and limits. Staying within your limits may help you to avoid an accident.
b. Only lend your machine to experienced operators.
3. Many machine accidents have been caused by machine operator errors. A typical error made by the operator is veering
wide on a turn due to EXCESSIVE SPEED or undercornering (insufficient lean angle for the speed). Never travel faster
than warranted by conditions.
4. Ride cautiously in unfamiliar areas. You may encounter hidden obstacles which could cause an accident.
5. The operator’s posture is important for proper control. The operator should keep both hands on the handlebars and
both feet on the operator footrests during operation to maintain control of the machine.
6. Never ride under the influence of alcohol or drugs.
SAFETY INFORMATION

VIII
PROTECTIVE APPAREL
The majority of fatalities from machine accidents are the result of head injuries. The use of a safety helmet is the single
most critical factor in the prevention or reduction of head injuries.
1. Always wear an approved helmet.
2. Wear a face shield or goggles. Wind on your unprotected eyes could contribute to an impairment of vision which could
delay seeing a hazard.
3. The use of heavy boots, jacket, trousers, gloves, etc. is effective in preventing or reducing abrasions or lacerations.
4. Never wear loose fitting clothing. It could catch on the control levers, footrests, or wheels and cause injury or accident.
5. Never touch the engine or exhaust system during or after operation. They become very hot and can cause burns.
Always wear protective clothing that covers your legs, ankles and feet.
6. Always use clear clothes to make your visualization easier.
7. Items above must also be followed by pillion rider.
MODIFICATION
Modifications made to the machine not approved by Yamaha, or the removal of original equipment, may render your
machine unsafe for use and may cause severe personal injury. Modifications may also make your machine illegal to use.
VIII
PROTECTIVE APPAREL
The majority of fatalities from machine accidents are the result of head injuries. The use of a safety helmet is the single
most critical factor in the prevention or reduction of head injuries.
1. Always wear an approved helmet.
2. Wear a face shield or goggles. Wind on your unprotected eyes could contribute to an impairment of vision which could
delay seeing a hazard.
3. The use of heavy boots, jacket, trousers, gloves, etc. is effective in preventing or reducing abrasions or lacerations.
4. Never wear loose fitting clothing. It could catch on the control levers, footrests, or wheels and cause injury or accident.
5. Never touch the engine or exhaust system during or after operation. They become very hot and can cause burns.
Always wear protective clothing that covers your legs, ankles and feet.
6. Always use clear clothes to make your visualization easier.
7. Items above must also be followed by pillion rider.
MODIFICATION
Modifications made to the machine not approved by Yamaha, or the removal of original equipment, may render your
machine unsafe for use and may cause severe personal injury. Modifications may also make your machine illegal to use.

CONTENTS
DESCRIPTION............................................................. 1-1
MACHINE IDENTIFICATION ....................................... 2-1
Vehicle identification number ................................. 2-1
Engine serial number ............................................ 2-1
CONTROL FUNCTIONS .............................................. 3-1
Main switch ............................................................ 3-1
Indicator lights ........................................................ 3-2
Speedometer .......................................................... 3-3
Fuel gauge ............................................................. 3-3
Handlebar switches over left .................................. 3-4
Handlebar switches over right .............................. 3-5
Clutch lever .......................... .................................. 3-6
Shift pedal ............................................................. 3-6
Front brake lever ................................................... 3-7
Rear brake pedal ................................................... 3-7
Fuel tank cap ......................................................... 3-8
Fuel cock ............................................................... 3-9
Starter lever ......................................................... 3-10
Steering lock ....................... ................................ 3-11
Seat ...................................................................... 3-12
Side covers ......................................................... 3-13
Rear shock absorber adjustment........................ 3-14
Clutch switch operation check ............................ 3-15
XIPRE-OPERATION
CHECKS........................................ 4-1
Brakes ................................................................... 4-3
Brake fluid leakage ................................................ 4-4
Engine oil ................................................................ 4-4
Tires ........................................................................\
4-5
Clutch ..................................................................... 4-8
Throttle grip ............................ ................................ 4-8
Fitting/Fasteners .................................................... 4-8
Switches ................................................................ 4-8
Wheels ......................................................... 4-8
Fuel ........................................................... 4-9
OPERATION AND IMPORT ANT RIDING POINTS....... 5-1
Starting a cold engine .................................................. 5-2
Starting a warm engine ................................................ 5-4
Warming up the engine ................................................ 5-4
Shifting ........................................................................\
.. 5-5
Engine Break-in ............................................................ 5-6
Parking ........................................................................\
.. 5-7
CONTENTS
DESCRIPTION ............................................................. 1-1
MACHINE IDENTIFICATION ....................................... 2-1
Vehicle identification number ................................. 2-1
Engine serial number ............................................ 2-1
CONTROL FUNCTIONS .............................................. 3-1
Main switch ............................................................ 3-1
Indicator lights ........................................................ 3-2
Speedometer .......................................................... 3-3
Fuel gauge ............................................................. 3-3
Handlebar switches over left .................................. 3-4
Handlebar switches over right .............................. 3-5
Clutch lever .......................... .................................. 3-6
Shift pedal ............................................................. 3-6
Front brake lever ................................................... 3-7
Rear brake pedal ................................................... 3-7
Fuel tank cap ......................................................... 3-8
Fuel cock ............................................................... 3-9
Starter lever ......................................................... 3-10
Steering lock ....................... ................................ 3-11
Seat ...................................................................... 3-12
Side covers ......................................................... 3-13
Rear shock absorber adjustment........................ 3-14
Clutch switch operation check ............................ 3-15
XIPRE-OPERATION
CHECKS........................................ 4-1
Brakes ................................................................... 4-3
Brake fluid leakage ................................................ 4-4
Engine oil ................................................................ 4-4
Tires ........................................................................\
4-5
Clutch ..................................................................... 4-8
Throttle grip ............................ ................................ 4-8
Fitting/Fasteners .................................................... 4-8
Switches ................................................................ 4-8
Wheels ......................................................... 4-8
Fuel ........................................................... 4-9
OPERATION AND IMPORT ANT RIDING POINTS....... 5-1
Starting a cold engine .................................................. 5-2
Starting a warm engine ................................................ 5-4
Warming up the engine ................................................ 5-4
Shifting ........................................................................\
.. 5-5
Engine Break-in ............................................................ 5-6
Parking ........................................................................\
.. 5-7

PERIODIC MAINTENANCE AND MINOR REPAIRS..... 6-1
Tool kit..................................................................... 6-2
PERIODIC MAINTENANCE/LUBRICATION......... 6-3
Torque specifications............................................. 6-5
Engine oil................................................................ 6-6
Oil pressure ............................................................ 6-9
Air filter .................................................................6-10
Carburetor adjustment ......................................... 6-12
Valve clearance adjustment.................................6-12
Idle speed adjustment..........................................6-13
Throttle cable adjustment....................................6-14
Spark plug inspection...........................................6-15
Rear brake adjustment ......................................... 6-16
Brake light switch adjustment ..............................6-17
Checking the front brake pads and rear brake
shoes.................................................................... 6-17
Front brake...........................................................6-18
Rear brake ............................................................ 6-18
Inspecting the brake fluid level ............................6-19
Brake fluid replacement.......................................6-20
Clutch adjustment................................................6-20
Drive chain slack check .......................................6-21
Drive chain slack adjustment...............................6-22
Drive chain lubrication..........................................6-23
Cable inspection and lubrication..........................6-23
Throttle cable and grip lubrication.......................6-24Brake and shift pedals ......................................... 6-24
Brake and clutch levers ....................................... 6-24
Sidestand ............................................................. 6-24
Front fork inspection ............................................ 6-25
Steering inspection.............................................. 6-26
Wheel bearings.................................................... 6-26
Battery.................................................................. 6-27
Replenishing the battery fluid .............................. 6-28
Fuse replacement................................................ 6-29
Headlight bulb replacement................................. 6-30
Turn signal bulb replacement.............................. 6-32
Taillight bulb replacement.................................... 6-32
Front wheel removal............................................. 6-33
Front wheel installation........................................ 6-34
Rear wheel removal............................................. 6-35
Rear wheel installation ......................................... 6-36
Troubleshooting.................................................... 6-36
Troubleshooting chart.......................................... 6-37
CLEANING AND STORAGE....................................... 7-1
CLEANING............................................................. 7-1
STORAGE.............................................................. 7-2
SPECIFICATIONS ........................................................ 8-1
XII
PERIODIC MAINTENANCE AND MINOR REPAIRS..... 6-1
Tool kit..................................................................... 6-2
PERIODIC MAINTENANCE/LUBRICATION......... 6-3
Torque specifications............................................. 6-5
Engine oil................................................................ 6-6
Oil pressure ............................................................ 6-9
Air filter .................................................................6-10
Carburetor adjustment ......................................... 6-12
Valve clearance adjustment.................................6-12
Idle speed adjustment..........................................6-13
Throttle cable adjustment....................................6-14
Spark plug inspection...........................................6-15
Rear brake adjustment ......................................... 6-16
Brake light switch adjustment ..............................6-17
Checking the front brake pads and rear brake
shoes.................................................................... 6-17
Front brake...........................................................6-18
Rear brake ............................................................ 6-18
Inspecting the brake fluid level ............................6-19
Brake fluid replacement.......................................6-20
Clutch adjustment................................................6-20
Drive chain slack check .......................................6-21
Drive chain slack adjustment...............................6-22
Drive chain lubrication..........................................6-23
Cable inspection and lubrication..........................6-23
Throttle cable and grip lubrication.......................6-24Brake and shift pedals ......................................... 6-24
Brake and clutch levers ....................................... 6-24
Sidestand ............................................................. 6-24
Front fork inspection ............................................ 6-25
Steering inspection.............................................. 6-26
Wheel bearings.................................................... 6-26
Battery.................................................................. 6-27
Replenishing the battery fluid .............................. 6-28
Fuse replacement................................................ 6-29
Headlight bulb replacement................................. 6-30
Turn signal bulb replacement.............................. 6-32
Taillight bulb replacement.................................... 6-32
Front wheel removal............................................. 6-33
Front wheel installation........................................ 6-34
Rear wheel removal............................................. 6-35
Rear wheel installation ......................................... 6-36
Troubleshooting.................................................... 6-36
Troubleshooting chart.......................................... 6-37
CLEANING AND STORAGE....................................... 7-1
CLEANING............................................................. 7-1
STORAGE.............................................................. 7-2
SPECIFICATIONS ........................................................ 8-1
XII

PRE-OPERATION CHECKS
Before using this motorcycle, check the following points:
ITEM ROUTINE
PAGE
Front brake
Check operation, condition and free play.
Adjust if necessary
Clutch
Throttle grip / cableCheck for smooth operation.
Lubricate / Adjust if necessary
Check oil level / add oil as necessary
Engine oil
Drive chainCheck chain slack and condition. Lubricate if necessary
Adjust if necessary.
Air filter
Control and meter cableCheck tire pressure, wear, damage and spoke tightness
Check for smooth operation.
Lubricate if necessary4-3 ~ 4-4
6-16 ~ 6-20
4-8 , 6-14 , 6-24
4-4 , 6-6 , 6-9
6-21 ~ 6-23
6-10 ~ 6-11
4-5 ~ 4-8 , 6-26
6-23 Check operation, condition and free play.
Adjust if necessary
Wheels / Tires
Clean and oil it frequently.4-8 , 6-20 Rear brakeCheck operation, free play, fluid level and fluid leakage.
Top-up with DOT #4 (or DOT #3) brake fluid if necessary.

PRE-OPERATION CHECKS
Before using this motorcycle, check the following points:
ITEM ROUTINE
PAGE
Front brake
Check operation, condition and free play.
Adjust if necessary
Clutch
Throttle grip / cableCheck for smooth operation.
Lubricate / Adjust if necessary
Check oil level / add oil as necessary
Engine oil
Drive chainCheck chain slack and condition. Lubricate if necessary
Adjust if necessary.
Air filter
Control and meter cableCheck tire pressure, wear, damage and spoke tightness
Check for smooth operation.
Lubricate if necessary4-3 ~ 4-4
6-16 ~ 6-20
4-8 , 6-14 , 6-24
4-4 , 6-6 , 6-9
6-21 ~ 6-23
6-10 ~ 6-11
4-5 ~ 4-8 , 6-26
6-23 Check operation, condition and free play.
Adjust if necessary
Wheels / Tires
Clean and oil it frequently.4-8 , 6-20 Rear brakeCheck operation, free play, fluid level and fluid leakage.
Top-up with DOT #4 (or DOT #3) brake fluid if necessary.


4-7 After extensive tests, the tires listed below have been
approved by Yanaha for this model. The front and rear
tires should always be by the same manufacturer and
of the same design. No guarantee concerning handling
characteristics can be given if a tire combination other
than one approved by Yamaha is used on this
motorcycle.
Front
Rear
Size Manufacturer
Type
Minimum tire tread depth
(from and rear)0,8 mm (0.0315 in) 2.75-18 PIRELLI
42P MT 39
90/90-18 PIRELLI
57P MT 15
1. It is dangerous to ride with a worn-out tire. When
the tire tread begin to show signs of wear, replace
the tire immediately. Brakes, tires and related wheel
parts should be left to a Yamaha dealer.
2. Patching a punctured tube is not recommended. If
it is absolutely necessary to do so, use great care
and replace the tube as soon as possible with a
good quality replacement.
WARNING:WARNING:
4-7 After extensive tests, the tires listed below have been
approved by Yanaha for this model. The front and rear
tires should always be by the same manufacturer and
of the same design. No guarantee concerning handling
characteristics can be given if a tire combination other
than one approved by Yamaha is used on this
motorcycle.
Front
Rear
Size Manufacturer
Type
Minimum tire tread depth
(from and rear)0,8 mm (0.0315 in) 2.75-18 PIRELLI
42P MT 39
90/90-18 PIRELLI
57P MT 15
1. It is dangerous to ride with a worn-out tire. When
the tire tread begin to show signs of wear, replace
the tire immediately. Brakes, tires and related wheel
parts should be left to a Yamaha dealer.
2. Patching a punctured tube is not recommended. If
it is absolutely necessary to do so, use great care
and replace the tube as soon as possible with a
good quality replacement.
WARNING:WARNING:

4-8Wheels
To ensure maximum performance, long service, and safe
operation, note the following:
1. Always inspect the wheels before a ride. Check for
cracks, bends, or warpage of the wheel; be sure the
spokes are tight and undamaged. If any abnormal
condition exists in a wheel, consult a Yamaha dealer or
other qualified mechanic. Do not attempt even small
repairs to the wheel. If a wheel is deformed or cracked,
it must be replaced.
2. Tires and wheels should be balanced whenever either one is changed or replaced. Failure to have a wheel
balanced can result in poor performance, adverse
handling characteristics, and shortened tire life.
3. After installing a tire, ride conservatively to allow the tire to seat itself on the rim properly. Failure to allow
proper seating may cause tire failure, resulting in
damage to the motorcycle and injury to the rider.
Clutch
( See page 6-20 for details)
Check the free play in the clutch lever, and make sure the
lever operates properly. If the free play is incorrect, adjust
it.
Throttle grip (See page 6-24 for details)
Turn the throttle grip to see if it operates properly, and check
the free play.
Make sure the grip returns by spring force when released.
Ask a Yamaha dealer or other qualified mechanic to make
any necessary adjustments.
Fitting/Fasteners
Alway check the tightness of chassis fittings and fasteners
before a ride. Use the chart on page 6-5 to find the correct
torque.
Switches
Check the operation of the starter switch, main switch, “
Engine Stop” switch.
4-8Wheels
To ensure maximum performance, long service, and safe
operation, note the following:
1. Always inspect the wheels before a ride. Check for
cracks, bends, or warpage of the wheel; be sure the
spokes are tight and undamaged. If any abnormal
condition exists in a wheel, consult a Yamaha dealer or
other qualified mechanic. Do not attempt even small
repairs to the wheel. If a wheel is deformed or cracked,
it must be replaced.
2. Tires and wheels should be balanced whenever either one is changed or replaced. Failure to have a wheel
balanced can result in poor performance, adverse
handling characteristics, and shortened tire life.
3. After installing a tire, ride conservatively to allow the tire to seat itself on the rim properly. Failure to allow
proper seating may cause tire failure, resulting in
damage to the motorcycle and injury to the rider.
Clutch
( See page 6-20 for details)
Check the free play in the clutch lever, and make sure the
lever operates properly. If the free play is incorrect, adjust
it.
Throttle grip (See page 6-24 for details)
Turn the throttle grip to see if it operates properly, and check
the free play.
Make sure the grip returns by spring force when released.
Ask a Yamaha dealer or other qualified mechanic to make
any necessary adjustments.
Fitting/Fasteners
Alway check the tightness of chassis fittings and fasteners
before a ride. Use the chart on page 6-5 to find the correct
torque.
Switches
Check the operation of the starter switch, main switch, “
Engine Stop” switch.

6-3
PERIODIC MAINTENANCE / LUBRICATION
Wheel bearings* Battery*
Check looseness and damage.
Check electrolyte level, routing breather pipe.
ITEM
How it sounds
/ Adjust if necessary.
REMARKS 1,000KM
Fuel line
Air filter
Carburetor* Valves*
Muffler
Brakes* Engine oil
Steering bearings* Rear arm pivot* Check fuel hose, for cracks or damage.
Clean or replace if necessary.
Adjust
Check damage, Retighten.
Check operation, adjust.
Grease the brake cam. Replace / Check level
Check loosenes.
Repack every 12,000 km or 12 month.** Check rear arm assembly for looseness.
Moderately repack.***
EVERY
3,000KM
OR ERERY
6 MONTHS
Wheels* and tires Check tire pressure, runout and spoke tightness.
Spark plug Check condition and clean if necessary.
Replace if necessary every 12,000 Km.
3,000KM
6-3
PERIODIC MAINTENANCE / LUBRICATION
Wheel bearings* Battery*
Check looseness and damage.
Check electrolyte level, routing breather pipe.
ITEM
How it sounds
/ Adjust if necessary.
REMARKS 1,000KM
Fuel line
Air filter
Carburetor* Valves*
Muffler
Brakes* Engine oil
Steering bearings* Rear arm pivot* Check fuel hose, for cracks or damage.
Clean or replace if necessary.
Adjust
Check damage, Retighten.
Check operation, adjust.
Grease the brake cam. Replace / Check level
Check loosenes.
Repack every 12,000 km or 12 month.** Check rear arm assembly for looseness.
Moderately repack.***
EVERY
3,000KM
OR ERERY
6 MONTHS
Wheels* and tires Check tire pressure, runout and spoke tightness.
Spark plug Check condition and clean if necessary.
Replace if necessary every 12,000 Km.
3,000KM