YAMAHA YBR125 2006 Workshop Manual
Page 51 of 84
PERIODIC MAINTENANCE AND MINOR REPAIR
6-19
6
WARNING
EWA10680
After adjusting the drive chain
slack or removing and installing
the rear wheel, always check the
brake pedal free play.
If proper adjustment cannot be
obtained as described, have a
Yamaha dealer make this ad-
justment.
After adjusting the brake pedal
free play, check the operation ofthe brake light.
EAU22291
Adjusting the rear brake light
switch The rear brake light switch, which is ac-
tivated by the brake pedal, is properly
adjusted when the brake light comes
on just before braking takes effect. If
necessary, adjust the brake light switch
as follows.
1. Remove panel A. (See page 6-5.)
2. Turn the adjusting nut while hold-
ing the rear brake light switch in
place. To make the brake light
come on earlier, turn the adjusting
nut in direction (a). To make the
brake light come on later, turn the
adjusting nut in direction (b).3. Install the panel.
1. Brake pedal free play adjusting nut
1. Rear brake light switch
2. Rear brake light switch adjusting nut
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EAU22380
Checking the front brake pads
and rear brake shoes The front brake pads and the rear brake
shoes must be checked for wear at the
intervals specified in the periodic main-
tenance and lubrication chart.
EAU37060
Front brake pads
The front brake is provided with a check
plug, which, if it is removed, allows you
to check the brake pad wear without
disassembling the brake. To check the
brake pad wear, check the position of
the wear indicator while applying the
brake. If a brake pad has worn to thepoint that the wear indicator almost
touches the brake disc, have a Yamaha
dealer replace the brake pads as a set.
EAU22540
Rear brake shoes
The rear brake is provided with a wear
indicator, which allows you to check the
brake shoe wear without having to dis-
assemble the brake. To check the
brake shoe wear, check the position of
the wear indicator while applying the
brake. If a brake shoe has worn to the
point that the wear indicator reaches
the wear limit line, have a Yamaha
dealer replace the brake shoes as a
set.
EAU37000
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:
1. Brake pad wear indicator
1. Brake shoe wear limit line
2. Brake shoe wear indicator
1. Minimum level mark
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PERIODIC MAINTENANCE AND MINOR REPAIR
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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 for the front brake system.
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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EAU22760
Drive chain slack The drive chain slack should be
checked before each ride and adjusted
if necessary.
EAU22791
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.
EAU37111
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
1. Alignment marks
2. Chain puller locknut
3. Drive chain slack adjusting bolt
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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 6-18.)
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:
91 Nm (9.1 m·kgf, 66 ft·lbf)
Brake torque rod nut:
19 Nm (1.9 m·kgf, 13 ft·lbf)
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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.
EAU23131
Checking and lubricating the
brake and shift pedals The operation of the brake and shift
pedals should be checked before each
ride, and the pedal pivots should be lu-
bricated if necessary.
Recommended lubricant:
Engine oil
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EAU23140
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:
Lithium-soap-based grease (all-pur-
pose grease)
Recommended lubricant:
Lithium-soap-based grease (all-pur-
pose grease)
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Page 58 of 84
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EAU23191
Checking and lubricating the
centerstand The operation of the centerstand
should be checked before each ride,
and the pivots and metal-to-metal con-
tact surfaces should be lubricated if
necessary.
WARNING
EWA11300
If the centerstand does not move up
and down smoothly, have a Yamahadealer check or repair it.
EAUM1650
Lubricating the swingarm
pivots The swingarm pivots must be lubricat-
ed at the intervals specified in the peri-
odic maintenance and lubrication chart.
EAU23271
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
WARNING
EWA10750
Securely support the vehicle so thatthere is no danger of it falling over.
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.
2. While applying the front brake,
push down hard on the handlebars
several times to check if the front
fork compresses and rebounds
smoothly.
Recommended lubricant:
Lithium-soap-based grease (all-pur-
pose grease)
Recommended lubricant:
Lithium-soap-based grease
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CAUTION:
ECA10590
If any damage is found or the front
fork does not operate smoothly,
have a Yamaha dealer check or re-pair it.
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.
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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.
EAU23321
Battery A poorly maintained battery will corrode
and discharge quickly. The electrolyte
level, battery lead connections and
breather hose routing should be
checked before each ride and at the in-
tervals specified in the periodic mainte-
nance and lubrication chart.
To check the electrolyte level
1. Place the vehicle on a level sur-
face and hold it in an upright posi-
tion.NOTE:Make sure that the vehicle is positioned
straight up when checking the electro-lyte level.
2. Remove panel B. (See page 6-5.)
3. Check the electrolyte level in the
battery.NOTE:The electrolyte should be between theminimum and maximum level marks.4. If the electrolyte is at or below the
minimum level mark, add distilled
water to raise it to the maximum
level mark.
WARNING
EWA10770
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
1. Maximum level mark
2. Minimum level mark
3. Negative battery lead
4. Positive battery lead (red)
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