YAMAHA YBR125 2008 Repair Manual

PERIODIC MAINTENANCE AND MINOR REPAIR
6-29
6
CAUTION:
ECA10640
Do not use a fuse of a higher amper-
age rating than recommended to
avoid causing extensive damage to
the electrical system and possibly afire.
3. Turn the key to “ON” and turn on
the electrical circuits to check if the
devices operate.
4. If the fuse immediately blows
again, have a Yamaha dealer
check the electrical system.
EAU43190
Replacing the headlight bulb This model is equipped with a quartz
bulb headlight. If the headlight bulb
burns out, replace it as follows.
1. Remove the headlight unit by re-
moving the screws.
2. Remove the headlight bulb socket
cover.3. Remove the headlight bulb socket
(together with the bulb) by turning
it counterclockwise.
4. Remove the defective bulb by
pushing it in and turning it counter-
clockwise.1. Screw
1. Headlight bulb socket cover
1. Headlight bulb socket
1
U27SE0E0.book Page 29 Friday, February 22, 2008 8:54 AM

PERIODIC MAINTENANCE AND MINOR REPAIR
6-30
6
WARNING
EWA10790
Headlight bulbs get very hot. There-
fore, keep flammable products away
from a lit headlight bulb, and do not
touch the bulb until it has cooleddown.
5. Insert a new bulb into the socket,
push it in, and then turn it clock-
wise until it stops.CAUTION:
ECA10660
Do not touch the glass part of the
headlight bulb to keep it free from
oil, otherwise the transparency of
the glass, the luminosity of the bulb,
and the bulb life will be adversely af-fected. Thoroughly clean off any dirt
and fingerprints on the headlight
bulb using a cloth moistened with al-
cohol or thinner.
6. Install the socket (together with the
bulb) by turning it clockwise.
7. Install the headlight bulb socket
cover.
8. Install the headlight unit by install-
ing the screws.
9. Have a Yamaha dealer adjust the
headlight beam if necessary.
EAU24131
Replacing the tail/brake light
bulb 1. Remove the tail/brake light lens by
removing the screws.
2. Remove the defective bulb by
pushing it in and turning it counter-
clockwise.
1. Headlight bulb
1. Do not touch the glass part of the bulb.
1. Screw
1
U27SE0E0.book Page 30 Friday, February 22, 2008 8:54 AM

PERIODIC MAINTENANCE AND MINOR REPAIR
6-31
6 3. Insert a new bulb into the socket,
push it in, and then turn it clock-
wise until it stops.
4. Install the lens by installing the
screws.
CAUTION:
ECA10680
Do not overtighten the screws, oth-erwise the lens may break.
EAU24202
Replacing a turn signal light
bulb 1. Remove the turn signal light lens
by removing the screw.
2. Remove the defective bulb by
pushing it in and turning it counter-
clockwise.
3. Insert a new bulb into the socket,
push it in, and then turn it clock-
wise until it stops.
4. Install the lens by installing the
screw.CAUTION:
ECA11190
Do not overtighten the screw, other-wise the lens may break.
EAU37270
Replacing the auxiliary light
bulb If the auxiliary light bulb burns out, re-
place it as follows.
1. Remove the headlight unit by re-
moving the screws.
2. Remove the socket (together with
the bulb) by pulling it out.
1. Tail/brake light bulb
1
1. Screw
1
1. Screw
U27SE0E0.book Page 31 Friday, February 22, 2008 8:54 AM

PERIODIC MAINTENANCE AND MINOR REPAIR
6-32
63. Remove the defective bulb by pull-
ing it out.
4. Insert a new bulb into the socket.
5. Install the socket (together with the
bulb) by pushing it in.
6. Install the headlight unit by install-
ing the screws.
EAU24360
Front wheel
EAU37041
To remove the front wheel
WARNING
EWA10820


It is advisable to have a Yamaha
dealer service the wheel.


Securely support the motor-
cycle so that there is no dangerof it falling over.
1. Place the motorcycle on the cen-
terstand.
2. Disconnect the speedometer ca-
ble from the front wheel.3. Remove the rubber caps from the
ends of the wheel axle by pulling
them off.
4. Remove the axle nut and the
washer.
1. Auxiliary light bulb socket
1. Auxiliary light bulb
1. Speedometer cable
1. Rubber cap
2. Axle nut
3. Washer
U27SE0E0.book Page 32 Friday, February 22, 2008 8:54 AM

PERIODIC MAINTENANCE AND MINOR REPAIR
6-33
6 5. Pull the wheel axle out, and then
remove the wheel.
CAUTION:
ECA11070
Do not apply the brake after the
wheel has been removed together
with the brake disc, otherwise thebrake pads will be forced shut.
EAU37030
To install the front wheel
1. Install the speedometer gear unit
into the wheel hub so that the pro-
jections mesh with the slots.2. Lift the wheel up between the fork
legs.
NOTE:
Make sure that there is enough space
between the brake pads before insert-
ing the brake disc and that the slot in
the speedometer gear unit fits over theretainer on the fork leg.3. Insert the wheel axle, making sure
the washer on the left side is in-
stalled with the beveled side facing
outward, and then install the axle
nut.
4. Take the motorcycle off the center-
stand so that the front wheel is on
the ground.
5. Tighten the axle nut to the speci-
fied torque, and then install both
rubber caps so that they fit over the
washers.
1. Rubber cap
2. Wheel axle
3. Washer
1. Speedometer gear unit
1. Speedometer gear unit retainer
Tightening torque:
Axle nut:
59 Nm (5.9 m·kgf, 43 ft·lbf)
U27SE0E0.book Page 33 Friday, February 22, 2008 8:54 AM

PERIODIC MAINTENANCE AND MINOR REPAIR
6-34
66. While applying the front brake,
push down hard on the handlebars
several times to check if the front
fork compresses and rebounds
smoothly.
7. Connect the speedometer cable.
EAU25080
Rear wheel
EAU37180
To remove the rear wheel
WARNING
EWA10820


It is advisable to have a Yamaha
dealer service the wheel.


Securely support the motor-
cycle so that there is no dangerof it falling over.
1. Loosen the axle nut and the brake
torque rod nut at the brake shoe
plate.
2. Disconnect the brake torque rod
from the brake shoe plate by re-
moving the cotter pin, the nut, and
the bolt.3. Place the motorcycle on the cen-
terstand.
4. Remove the brake pedal free play
adjusting nut, and then disconnect
the brake rod from the brake cam-
shaft lever.
1. Axle nut
2. Brake torque rod
3. Brake torque rod cotter pin
4. Brake torque rod nut and bolt
32 1
4
U27SE0E0.book Page 34 Friday, February 22, 2008 8:54 AM

PERIODIC MAINTENANCE AND MINOR REPAIR
6-35
6 5. Loosen the chain puller locknut
and the drive chain slack adjusting
bolt on both ends of the swingarm.6. Remove the axle nut, and then pull
the wheel axle out.
7. Push the wheel forward, and then
remove the drive chain from the
rear sprocket.
NOTE:The drive chain does not need to be
disassembled in order to remove andinstall the wheel.
8. Remove the wheel.
EAU37192
To install the rear wheel
1. Install the wheel by inserting the
wheel axle from the left-hand side.
2. Install the drive chain onto the rear
sprocket.
3. Install the axle nut.
4. Install the brake rod onto the brake
camshaft lever, and then install the
brake pedal free play adjusting nut
onto the brake rod.
5. Connect the brake torque rod to
the brake shoe plate by installing
the bolt and nut.
6. Adjust the drive chain slack. (See
page 6-21.)7. Take the motorcycle off the center-
stand so that the rear wheel is on
the ground.
8. Tighten the brake torque rod nut
and axle nut to the specified
torques.
9. Insert a new cotter pin.
10. 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.
1. Brake pedal free play adjusting nut
2. Brake rod
3. Brake camshaft lever
1. Wheel axle
2. Chain puller locknut
3. Drive chain slack adjusting bolt1
23
Tightening torques:
Brake torque rod nut:
19 Nm (1.9 m·kgf, 13 ft·lbf)
Axle nut:
80 Nm (8.0 m·kgf, 58 ft·lbf)
U27SE0E0.book Page 35 Friday, February 22, 2008 8:54 AM

PERIODIC MAINTENANCE AND MINOR REPAIR
6-36
6
EAU25850
Troubleshooting Although Yamaha motorcycles receive
a thorough inspection before shipment
from the factory, trouble may occur dur-
ing operation. Any problem in the fuel,
compression, or ignition systems, for
example, can cause poor starting and
loss of power.
The following troubleshooting chart
represents a quick and easy procedure
for checking these vital systems your-
self. However, should your motorcycle
require any repair, take it to a Yamaha
dealer, whose skilled technicians have
the necessary tools, experience, and
know-how to service the motorcycle
properly.
Use only genuine Yamaha replace-
ment parts. Imitation parts may look like
Yamaha parts, but they are often inferi-
or, have a shorter service life and can
lead to expensive repair bills.U27SE0E0.book Page 36 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
7-1
7
EAU37833
Matte color caution CAUTION:
ECA15192
Some models are equipped with
matte colored finished parts. Be
sure to consult a Yamaha dealer for
advice on what products to use be-
fore cleaning the vehicle. Using a
brush, harsh chemical products or
cleaning compounds when cleaning
these parts will scratch or damage
their surface. Wax also should not
be applied to any matte colored fin-ished parts.
EAU26002
Care While the open design of a motorcycle
reveals the attractiveness of the tech-
nology, it also makes it more vulnera-
ble. Rust and corrosion can develop
even if high-quality components are
used. A rusty exhaust pipe may go un-
noticed on a car, however, it detracts
from the overall appearance of a motor-
cycle. Frequent and proper care does
not only comply with the terms of the
warranty, but it will also keep your
motorcycle 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 in-
stalled.
3. Remove extremely stubborn dirt,
like oil burnt onto the crankcase,
with a degreasing agent and a
brush, but never apply such prod-ucts onto seals, gaskets, sprock-
ets, the drive chain and wheel
axles. Always rinse the dirt and de-
greaser off with water.
Cleaning
CAUTION:
ECA10771


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 af-
fected area any longer than in-
structed. Also, thoroughly rinse
the area off with water, immedi-
ately dry it, and then apply a cor-
rosion protection spray.


Improper cleaning can damage
plastic parts such as cowlings,
panels, windshields, headlight
lenses, meter lenses, etc. Use
only a soft, clean cloth or
sponge with mild detergent and
water to clean plastic.


Do not use any harsh chemical
products on plastic parts. Be
sure to avoid using cloths or
sponges which have been in
U27SE0E0.book Page 1 Friday, February 22, 2008 8:54 AM