2009 YAMAHA YBR125 wheel torque

PERIODIC MAINTENANCE AND ADJUSTMENT
6-20
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.
EAU37113
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
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 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
U3D9E2E0.book Page 20 Thursday, November 6, 2008 10:54 AM

PERIODIC MAINTENANCE AND ADJUSTMENT
6-33
6
TIPMake 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.
6. 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
EAU37181
To remove the rear wheel
WARNING
EWA10821
To avoid injury, securely support the
vehicle so there is no danger of itfalling 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.
1. Speedometer gear unit retainer
Tightening torque:
Axle nut:
59 Nm (5.9 m·kgf, 43 ft·lbf)
U3D9E2E0.book Page 33 Thursday, November 6, 2008 10:54 AM

PERIODIC MAINTENANCE AND ADJUSTMENT
6-34
6 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.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.
TIPThe 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 6-20.)
1. Axle nut
2. Brake torque rod
3. Brake torque rod cotter pin
4. Brake torque rod nut and bolt
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 bolt
U3D9E2E0.book Page 34 Thursday, November 6, 2008 10:54 AM

PERIODIC MAINTENANCE AND ADJUSTMENT
6-35
67. 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.
EAU25851
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.
WARNING
EWA15141
When checking the fuel system, do
not smoke, and make sure there are
no open flames or sparks in the ar-
ea, including pilot lights from waterheaters or furnaces. Gasoline or
gasoline vapors can ignite or ex-
plode, causing severe injury or
property damage.
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)
U3D9E2E0.book Page 35 Thursday, November 6, 2008 10:54 AM