YAMAHA YBR125 2010 Workshop Manual

PERIODIC MAINTENANCE AND ADJUSTMENT
6-19
6
EAU37001
Checking the front brake fluid
level Insufficient brake fluid may allow air to
enter the brake system, possibly caus-
ing 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 fluid 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 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.
TIPIf 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 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.
1. Minimum level mark
Recommended brake fluid:
DOT 4
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PERIODIC MAINTENANCE AND ADJUSTMENT
6-20
6
EAU22721
Changing the brake fluid Have a Yamaha dealer change the
brake fluid at the intervals specified in
the TIP after the periodic maintenance
and lubrication chart. In addition, have
the oil seals of the brake master cylin-
der and caliper as well as the brake
hose replaced at the intervals listed be-
low or whenever they are damaged or
leaking.

Oil seals: Replace every two
years.


Brake hose: Replace every four
years.
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.
EAUP0060
To adjust the drive chain slack
1. Remove the brake torque rod cot-
ter pin, and then loosen the brake
pedal free play adjusting nut,
brake torque rod nut, and axle nut.
2. Loosen the drive chain puller lock-
nut at each end of the swingarm.
1. Drive chain slack
Drive chain slack:
20.0–30.0 mm (0.79–1.18 in)1. Drive chain slack adjusting bolt
2. Drive chain puller locknut
3. Axle nut
4. Brake torque rod nut
5. Brake torque rod cotter pin
6. Brake pedal free play adjusting nut
1
2
34
5
6
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PERIODIC MAINTENANCE AND ADJUSTMENT
6-21
6 3. To tighten the drive chain, turn the
drive chain slack adjusting bolt at
each end of the swingarm in direc-
tion (a). To loosen the drive chain,
turn the adjusting bolt at each end
of the swingarm in direction (b),
and then push the rear wheel for-
ward. NOTICE: Improper drive
chain slack will overload the en-
gine 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 with-
in the specified limits.
[ECA10571]
TIPUsing the alignment marks on each
side of the swingarm, make sure that
both drive chain pullers are in the same
position for proper wheel alignment.
4. Tighten both locknuts, and then
tighten the axle nut and brake
torque rod nut to their specified
torques.
5. Insert a new cotter pin.
6. Adjust the brake pedal free play.
(See page 6-16.)
WARNING
EWA10660
After adjusting the brake pedal free
play, check the operation of the
brake light.
1. Alignment marks
2. Drive chain puller
3. Drive chain puller locknut
4. Drive chain slack adjusting bolt
Tightening torques:
Axle nut:
80 Nm (8.0 m·kgf, 58 ft·lbf)
Brake torque rod nut:
19 Nm (1.9 m·kgf, 14 ft·lbf)
1
2
3
4
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PERIODIC MAINTENANCE AND ADJUSTMENT
6-22
6
EAU23025
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.NOTICE
ECA10583
The drive chain must be lubricated
after washing the motorcycle, riding
in the rain or riding in wet areas.1. Clean the drive chain with kero-
sene and a small soft brush.
NOTICE: To prevent damaging
the O-rings, do not clean the
drive chain with steam cleaners,
high-pressure washers or inap-
propriate solvents.
[ECA11121]
2. Wipe the drive chain dry.
3. Thoroughly lubricate the drive
chain with a special O-ring chain
lubricant. NOTICE: Do not use
engine oil or any other lubri-
cants for the drive chain, as theymay contain substances that
could damage the O-rings.
[ECA11111]EAU23101
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! Damage to the outer
sheath may interfere with proper ca-
ble operation and will cause the in-
ner cable to rust. Replace a
damaged cable as soon as possible
to prevent unsafe conditions.
[EWA10721]
Recommended lubricant:
Engine oil
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PERIODIC MAINTENANCE AND ADJUSTMENT
6-23
6
EAU23112
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 by a
Yamaha dealer at the intervals speci-
fied 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 lubricants:
Brake lever:
Silicone grease
Clutch lever:
Lithium-soap-based grease
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PERIODIC MAINTENANCE AND ADJUSTMENT
6-24
6
EAU23182
Checking and lubricating the
brake pedal The operation of the brake pedal
should be checked before each ride,
and the pedal pivot should be lubricat-
ed if necessary.
EAU23213
Checking and lubricating the
centerstand and sidestand The operation of the centerstand and
sidestand should be checked before
each ride, and the pivots and metal-to-
metal contact surfaces should be lubri-
cated if necessary.
WARNING
EWA10741
If the centerstand or sidestand does
not move up and down smoothly,
have a Yamaha dealer check or re-
pair it. Otherwise, the centerstand or
sidestand could contact the ground
and distract the operator, resulting
in a possible loss of control.
Recommended lubricant:
Lithium-soap-based grease
Recommended lubricant:
Lithium-soap-based grease
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PERIODIC MAINTENANCE AND ADJUSTMENT
6-25
6
EAUM1651
Lubricating the swingarm piv-
ots The swingarm pivots must be lubricat-
ed by a Yamaha dealer at the intervals
specified in the periodic maintenance
and lubrication chart.
EAU23272
Checking the front fork The condition and operation of the front
fork must be checked as follows at the
intervals specified in the periodic main-
tenance and lubrication chart.
To check the condition
Check the inner tubes for scratches,
damage and excessive oil leakage.
To check the operation
1. Place the vehicle on a level sur-
face and hold it in an upright posi-
tion. WARNING! To avoid injury,
securely support the vehicle so
there is no danger of it falling
over.
[EWA10751]
2. While applying the front brake,
push down hard on the handlebars
several times to check if the front
fork compresses and rebounds
smoothly.
NOTICE
ECA10590
If any damage is found or the front
fork does not operate smoothly,
have a Yamaha dealer check or re-
pair it.
Recommended lubricant:
Lithium-soap-based grease
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PERIODIC MAINTENANCE AND ADJUSTMENT
6-26
6
EAU45511
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 the vehicle on the center-
stand. WARNING! To avoid inju-
ry, securely support the vehicle
so there is no danger of it falling
over.
[EWA10751]
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.
EAU23291
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.
EAU23385
Battery The battery is located behind panel B.
(See page 6-6.)
This model is equipped with a VRLA
(Valve Regulated Lead Acid) battery.
There is no need to check the electro-
lyte or to add distilled water. However,
the battery lead connections need to be
checked and, if necessary, tightened.NOTICE
ECA10620
Never attempt to remove the battery
cell seals, as this would permanent-
ly damage the battery.1. Battery
2. Negative battery lead (black)
3. Positive battery lead (red)123
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PERIODIC MAINTENANCE AND ADJUSTMENT
6-27
6
WARNING
EWA10760


Electrolyte is poisonous and
dangerous since it contains sul-
furic acid, which causes severe
burns. Avoid any contact with
skin, eyes or clothing and al-
ways shield your eyes when
working near batteries. In case
of contact, administer the fol-
lowing FIRST AID.
EXTERNAL: Flush with plenty
of water.
INTERNAL: Drink large quan-
tities of water or milk and im-
mediately call a physician.
EYES: Flush with water for 15
minutes and seek prompt
medical attention.


Batteries produce explosive hy-
drogen gas. Therefore, keep
sparks, flames, cigarettes, etc.,
away from the battery and pro-
vide sufficient ventilation when
charging it in an enclosed
space.


KEEP THIS AND ALL BATTER-
IES OUT OF THE REACH OF
CHILDREN.
To charge the battery
Have a Yamaha dealer charge the bat-
tery as soon as possible if it seems to
have discharged. Keep in mind that the
battery tends to discharge more quickly
if the vehicle is equipped with optional
electrical accessories.NOTICE
ECA16520
To charge a VRLA (Valve Regulated
Lead Acid) battery, a special (con-
stant-voltage) battery charger is re-
quired. Using a conventional battery
charger will damage the battery. If
you do not have access to a con-
stant-voltage battery charger, have a
Yamaha dealer charge your battery.To store the battery
1. If the vehicle will not be used for
more than one month, remove the
battery, fully charge it, and then
place it in a cool, dry place.
NOTICE: When removing thebattery, be sure the key is
turned to “OFF”, then discon-
nect the negative lead before
disconnecting the positive lead.
[ECA16302]
2. If the battery will be stored for more
than two months, check it at least
once a month and fully charge it if
necessary.
3. Fully charge the battery before in-
stallation.
4. After installation, make sure that
the battery leads are properly con-
nected to the battery terminals.NOTICE
ECA16530
Always keep the battery charged.
Storing a discharged battery can
cause permanent battery damage.
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PERIODIC MAINTENANCE AND ADJUSTMENT
6-28
6
EAU43213
Replacing the fuse The fuse is located behind panel B.
(See page 6-6.)
To access the fuse, disconnect the
starter relay coupler.The spare fuse is located on the rear of
the starter relay holder.
To access the spare fuse, remove the
starter relay (together with its holder) by
pulling it out, then turn the starter relay
over.
If the fuse is blown, replace it as fol-
lows.
1. Turn the key to “OFF” and turn off
all electrical circuits.
2. Remove the blown fuse, and then
install a new fuse of the specified
amperage. WARNING! Do not
use a fuse of a higher amperage
rating than recommended toavoid causing extensive dam-
age to the electrical system and
possibly a fire.
[EWA15131]
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.
1. Starter relay coupler
1. Fuse
2. Starter relay holder
3. Starter relay
1
23
1. Spare fuse
2. Starter relay holder
3. Starter relay
1
23
Specified fuse:
15.0 A
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