2008 YAMAHA YBR125 check engine

PERIODIC MAINTENANCE AND MINOR REPAIR
6-22
6
CAUTION:
ECA10570
Improper drive chain slack will over-
load the engine as well as other vital
parts of the motorcycle and can lead
to chain slippage or breakage. To
prevent this from occurring, keep
the drive chain slack within thespecified limits.
4. Tighten both locknuts, and then
tighten the axle nut and brake
torque rod nut to their specified
torques.
5. Adjust the brake pedal free play.
(See page 6-17.)
WARNING
EWA10660
After adjusting the brake pedal free
play, check the operation of thebrake light.
EAU23022
Cleaning and lubricating the
drive chain The drive chain must be cleaned and
lubricated at the intervals specified in
the periodic maintenance and lubrica-
tion chart, otherwise it will quickly wear
out, especially when riding in dusty or
wet areas. Service the drive chain as
follows.CAUTION:
ECA10581
The drive chain must be lubricated
after washing the motorcycle andriding in the rain.
1. Clean the drive chain with kero-
sene and a small soft brush.CAUTION:
ECA11120
To prevent damaging the O-rings, do
not clean the drive chain with steam
cleaners, high-pressure washers orinappropriate solvents.
2. Wipe the drive chain dry.
3. Thoroughly lubricate the drive
chain with a special O-ring chain
lubricant.
CAUTION:
ECA11110
Do not use engine oil or any other lu-
bricants for the drive chain, as they
may contain substances that coulddamage the O-rings.
Tightening torques:
Axle nut:
80 Nm (8.0 m·kgf, 58 ft·lbf)
Brake torque rod nut:
19 Nm (1.9 m·kgf, 13 ft·lbf)
U27SE0E0.book Page 22 Friday, February 22, 2008 8:54 AM

PERIODIC MAINTENANCE AND MINOR REPAIR
6-23
6
EAU23100
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 ca-
bles and cable ends should be lubricat-
ed if necessary. If a cable is damaged
or does not move smoothly, have a
Yamaha dealer check or replace it.
WARNING
EWA10720
Damage to the outer sheath may in-
terfere with proper cable operation
and will cause the inner cable to
rust. Replace a damaged cable as
soon as possible to prevent unsafeconditions.
EAU23111
Checking and lubricating the
throttle grip and cable The operation of the throttle grip should
be checked before each ride. In addi-
tion, the cable should be lubricated at
the intervals specified in the periodic
maintenance chart.
EAU23142
Checking and lubricating the
brake and clutch levers Brake lever
Clutch lever
The operation of the brake and clutch
levers should be checked before each
ride, and the lever pivots should be lu-
bricated if necessary.
Recommended lubricant:
Engine oil
U27SE0E0.book Page 23 Friday, February 22, 2008 8:54 AM

PERIODIC MAINTENANCE AND MINOR REPAIR
6-26
6
EAU23280
Checking the steering Worn or loose steering bearings may
cause danger. Therefore, the operation
of the steering must be checked as fol-
lows at the intervals specified in the pe-
riodic maintenance and lubrication
chart.
1. Place a stand under the engine to
raise the front wheel off the
ground.
WARNING
EWA10750
Securely support the vehicle so thatthere is no danger of it falling over.
2. Hold the lower ends of the front
fork legs and try to move them for-
ward and backward. If any free
play can be felt, have a Yamaha
dealer check or repair the steering.
EAU23290
Checking the wheel bearings The front and rear wheel bearings must
be checked at the intervals specified in
the periodic maintenance and lubrica-
tion chart. If there is play in the wheel
hub or if the wheel does not turn
smoothly, have a Yamaha dealer check
the wheel bearings.
U27SE0E0.book Page 26 Friday, February 22, 2008 8:54 AM

PERIODIC MAINTENANCE AND MINOR REPAIR
6-37
6
EAU45730
Troubleshooting chart
WARNING
EWA10840
Keep away open flames and do not smoke while checking or working on the fuel system.
Check the fuel level in
the fuel tank.1. Fuel
There is enough fuel.
There is no fuel.
Check the compression.
Supply fuel.
The engine does not start.
Check the compression.
Operate the electric starter
or the kickstarter.2. Compression
There is compression.
There is no compression.
Check the ignition.
Have a Yamaha dealer
check the vehicle.
Remove the spark plug
and check the electrodes.3. Ignition
Wipe off with a dry cloth and correct the
spark plug gap, or replace the spark plug.
Have a Yamaha dealer check the vehicle.
The engine does not start.
Have a Yamaha dealer
check the vehicle.
The engine does not start.
Check the battery.
Operate the electric starter.4. Battery
The engine turns over
quickly.
The engine turns over
slowly.
The battery is good.Check the battery lead connections,
and charge the battery if necessary.
DryWet
Operate the electric starter
or the kickstarter.
U27SE0E0.book Page 37 Friday, February 22, 2008 8:54 AM

MOTORCYCLE CARE AND STORAGE
7-4
7 3. Perform the following steps to pro-
tect 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 spark-
ing 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.
WARNING
EWA10950
To prevent damage or injury from
sparking, make sure to ground the
spark plug electrodes while turningthe engine over.4. Lubricate all control cables and the
pivoting points of all levers and
pedals as well as of the side-
stand/centerstand.
5. Check and, if necessary, correct
the tire air pressure, and then lift
the motorcycle so that both of its
wheels are off the ground. Alterna-
tively, turn the wheels a little every
month in order to prevent the tires
from becoming degraded in one
spot.
6. Cover the muffler outlet with a
plastic bag to prevent moisture
from entering it.
7. 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 ex-
cessively cold or warm place [less
than 0 °C (30 °F) or more than 30
°C (90 °F)]. For more information
on storing the battery, see page
6-27.
NOTE:Make any necessary repairs beforestoring the motorcycle.
U27SE0E0.book Page 4 Friday, February 22, 2008 8:54 AM

INDEX
AAir filter element, cleaning .................... 6-10
Auxiliary light bulb, replacing ................ 6-31BBattery .................................................. 6-27
Brake and clutch levers,
checking and lubricating ..................... 6-23
Brake fluid, changing ............................ 6-20
Brake fluid level, checking .................... 6-19
Brake lever ............................................. 3-5
Brake pads and shoes, checking.......... 6-19
Brake pedal ............................................ 3-6
Brake pedal, checking and
lubricating ........................................... 6-24
Brake pedal free play, adjusting ........... 6-17CCables, checking and lubricating .......... 6-23
Care ........................................................ 7-1
Carrier..................................................... 3-9
Catalytic converters ................................ 3-8
Centerstand and sidestand,
checking and lubricating ..................... 6-24
Clutch lever............................................. 3-5
Clutch lever free play, adjusting ........... 6-16DDimmer switch ........................................ 3-4
Drive chain, cleaning and lubricating .... 6-22
Drive chain slack .................................. 6-21EEngine break-in ...................................... 5-3
Engine idling speed, checking .............. 6-12
Engine oil ................................................ 6-9
Engine trouble warning light ................... 3-2
FFront brake lever free play, checking .... 6-17
Front fork, checking...............................6-25
Fuel ......................................................... 3-7
Fuel consumption, tips for reducing ........ 5-3
Fuel gauge .............................................. 3-3
Fuel tank cap........................................... 3-6
Fuse, replacing...................................... 6-28HHandlebar switches ................................. 3-4
Headlight bulb, replacing....................... 6-29
High beam indicator light......................... 3-2
Horn switch ............................................. 3-4IIdentification numbers ............................. 9-1
Ignition circuit cut-off system ................. 3-10
Indicator and warning lights .................... 3-2KKey identification number ........................ 9-1
Kickstarter ............................................... 3-8MMain switch/steering lock ........................ 3-1
Matte color, caution .................................7-1
Model label .............................................. 9-2NNeutral indicator light .............................. 3-2PPanels, removing and installing .............. 6-6
Parking ....................................................5-4
Part locations .......................................... 2-1
Periodic maintenance and
lubrication chart.....................................6-2
Pre-operation check list........................... 4-2
RRear brake light switch, adjusting ......... 6-18SSafety information ................................... 1-1
Self-diagnosis device .............................. 3-3
Shifting .................................................... 5-2
Shift pedal ............................................... 3-5
Shift pedal, checking............................. 6-18
Shock absorber assemblies, adjusting ... 3-8
Sidestand ................................................ 3-9
Spark plug, checking .............................. 6-7
Specifications.......................................... 8-1
Speedometer unit ................................... 3-2
Starting the engine.................................. 5-1
Start switch ............................................. 3-4
Steering, checking ................................ 6-26
Storage ................................................... 7-3
Swingarm pivots, lubricating ................. 6-25TTachometer............................................. 3-3
Tail/brake light bulb, replacing .............. 6-30
Throttle cable free play, adjusting ......... 6-12
Throttle grip and cable,
checking and lubricating ..................... 6-23
Tires ...................................................... 6-13
Tool kit .................................................... 6-1
Troubleshooting .................................... 6-36
Troubleshooting chart ........................... 6-37
Turn signal indicator light ........................ 3-2
Turn signal light bulb, replacing ............ 6-31
Turn signal switch ................................... 3-4VValve clearance .................................... 6-13
Vehicle identification number .................. 9-1
U27SE0E0.book Page 1 Friday, February 22, 2008 8:54 AM