2008 YAMAHA YBR125 lock

PERIODIC MAINTENANCE AND MINOR REPAIR
6-16
6
EAU22032
Adjusting the clutch lever free
play The clutch lever free play should mea-
sure 10.0–15.0 mm (0.39–0.59 in) as
shown. Periodically check the clutch le-
ver free play and, if necessary, adjust it
as follows.
1. Loosen the locknut at the clutch le-
ver.
2. To increase the clutch lever free
play, turn the clutch lever free play
adjusting bolt in direction (a). To
decrease the clutch lever free play,
turn the adjusting bolt in direction
(b).3. If the specified clutch lever free
play could be obtained as de-
scribed above, tighten the locknut
and skip the rest of the procedure,
otherwise, proceed as follows.
4. Fully turn the adjusting bolt in di-
rection (a) to loosen the clutch ca-
ble.
5. Loosen the locknut further down
the clutch cable.
6. To increase the clutch lever free
play, turn the clutch lever free play
adjusting nut in direction (a). To
decrease the clutch lever free play,
turn the adjusting nut in direction
(b).7. Tighten both locknuts.1. Locknut (clutch lever)
2. Clutch lever free play adjusting bolt
3. Clutch lever free play
1. Locknut (clutch cable)
2. Clutch lever free play adjusting nut (clutch
cable)
1
2
(a) (b)
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PERIODIC MAINTENANCE AND MINOR REPAIR
6-20
6


When checking the fluid level,
make sure that the top of the mas-
ter 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 perfor-
mance.
NOTE:If DOT 4 is not available, DOT 3 can beused.

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 en-
ter the master cylinder when refill-
ing. Water will significantly lower
the boiling point of the fluid and
may result in vapor lock.


Brake fluid may deteriorate paint-
ed surfaces or plastic parts. Al-
ways clean up spilled fluid
immediately.


As the brake pads wear, it is nor-
mal for the brake fluid level to grad-
ually go down. However, if the
brake fluid level goes down sud-
denly, have a Yamaha dealer
check the cause.
EAU22720
Changing the brake fluid Have a Yamaha dealer change the
brake fluid at the intervals specified in
the NOTE after the periodic mainte-
nance and lubrication chart. In addition,
have the oil seals of the brake master
cylinder and caliper as well as the
brake hose replaced at the intervals
listed below or whenever they are dam-
aged or leaking.

Oil seals: Replace every two
years.


Brake hose: Replace every four
years.
Recommended brake fluid:
DOT 4
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PERIODIC MAINTENANCE AND MINOR REPAIR
6-21
6
EAU22760
Drive chain slack The drive chain slack should be
checked before each ride and adjusted
if necessary.
EAU22793
To check the drive chain slack
1. Place the motorcycle on the cen-
terstand.
2. Shift the transmission into the neu-
tral position.
3. Spin the rear wheel several times
to locate the tightest portion of the
drive chain.
4. Measure the drive chain slack as
shown.5. If the drive chain slack is incorrect,
adjust it as follows.
EAU37112
To adjust the drive chain slack
1. Loosen the brake pedal free play
adjusting nut, brake torque rod nut,
and axle nut.
2. Loosen the chain puller locknut at
each end of the swingarm.3. To tighten the drive chain, turn the
adjusting bolt at each end of the
swingarm in direction (a). To loos-
en the drive chain, turn the adjust-
ing bolt at each end of the
swingarm in direction (b), and then
push the rear wheel forward.
NOTE:Using the alignment marks on each
side of the swingarm, make sure that
both chain pullers are in the same posi-tion for proper wheel alignment.
1. Drive chain slack
Drive chain slack:
20.0–30.0 mm (0.79–1.18 in)
1. Drive chain slack adjusting bolt
2. Chain puller locknut
3. Axle nut
4. Brake torque rod nut
5. Brake pedal free play adjusting nut
4
5 12
3
1. Alignment marks
2. Chain puller locknut
3. Drive chain slack adjusting bolt
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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)
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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
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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
6-35
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