2008 YAMAHA YBR125 service

1-1
1
SAFETY INFORMATION
EAU10281
MOTORCYCLES ARE SINGLE
TRACK VEHICLES. THEIR SAFE USE
AND OPERATION ARE DEPENDENT
UPON THE USE OF PROPER RIDING
TECHNIQUES AS WELL AS THE EX-
PERTISE OF THE OPERATOR. EV-
ERY OPERATOR SHOULD KNOW
THE FOLLOWING REQUIREMENTS
BEFORE RIDING THIS MOTOR-
CYCLE.
HE OR SHE SHOULD:

OBTAIN THOROUGH INSTRUC-
TIONS FROM A COMPETENT
SOURCE ON ALL ASPECTS OF
MOTORCYCLE OPERATION.


OBSERVE THE WARNINGS AND
MAINTENANCE REQUIRE-
MENTS IN THE OWNER’S MAN-
UAL.


OBTAIN QUALIFIED TRAINING
IN SAFE AND PROPER RIDING
TECHNIQUES.


OBTAIN PROFESSIONAL TECH-
NICAL SERVICE AS INDICATED
BY THE OWNER’S MANUALAND/OR WHEN MADE NECES-
SARY BY MECHANICAL CONDI-
TIONS.
Safe riding


Always make pre-operation
checks. Careful checks may help
prevent an accident.


This motorcycle is designed to car-
ry the operator and a passenger.


The failure of motorists to detect
and recognize motorcycles in traf-
fic is the predominating cause of
automobile/motorcycle accidents.
Many accidents have been caused
by an automobile driver who did
not see the motorcycle. Making
yourself conspicuous appears to
be very effective in reducing the
chance of this type of accident.
Therefore:
Wear a brightly colored jacket.
Use extra caution when you are
approaching and passing
through intersections, since in-
tersections are the most likely
places for motorcycle accidents
to occur.Ride where other motorists can
see you. Avoid riding in another
motorist’s blind spot.


Many accidents involve inexperi-
enced operators. In fact, many op-
erators who have been involved in
accidents do not even have a cur-
rent motorcycle license.
Make sure that you are qualified
and that you only lend your
motorcycle to other qualified op-
erators.
Know your skills and limits.
Staying within your limits may
help you to avoid an accident.
We recommend that you prac-
tice riding your motorcycle
where there is no traffic until you
have become thoroughly famil-
iar with the motorcycle and all of
its controls.


Many accidents have been caused
by error of the motorcycle opera-
tor. A typical error made by the op-
erator is veering wide on a turn
U27SE0E0.book Page 1 Friday, February 22, 2008 8:54 AM

PERIODIC MAINTENANCE AND MINOR REPAIR
6-1
6
EAU17240
Safety is an obligation of the owner. Pe-
riodic inspection, adjustment and lubri-
cation will keep your vehicle in the
safest and most efficient condition pos-
sible. The most important points of in-
spection, adjustment, and lubrication
are explained on the following pages.
The intervals given in the periodic
maintenance and lubrication chart
should be simply considered as a gen-
eral guide under normal riding condi-
tions. However, DEPENDING ON THE
WEATHER, TERRAIN, GEOGRAPHI-
CAL LOCATION, AND INDIVIDUAL
USE, THE MAINTENANCE INTER-
VALS MAY NEED TO BE SHORT-
ENED.
WARNING
EWA10320
If you are not familiar with mainte-
nance work, have a Yamaha dealerdo it for you.
EAU17340
Owner’s tool kit The owner’s tool kit is located behind
panel A. (See page 6-6.)
The service information included in this
manual and the tools provided in the
owner’s tool kit are intended to assist
you in the performance of preventive
maintenance and minor repairs. How-
ever, additional tools such as a torque
wrench may be necessary to perform
certain maintenance work correctly.NOTE:If you do not have the tools or experi-
ence required for a particular job, havea Yamaha dealer perform it for you.
WARNING
EWA10350
Modifications not approved by
Yamaha may cause loss of perfor-
mance and render the vehicle un-
safe for use. Consult a Yamaha
dealer before attempting any chang-es.
1. Owner’s tool kit
1
U27SE0E0.book Page 1 Friday, February 22, 2008 8:54 AM

PERIODIC MAINTENANCE AND MINOR REPAIR
6-5
6
EAU18660
NOTE:

The air filter needs more frequent service if you are riding in unusually wet or dusty areas.


Hydraulic brake service
Regularly check and, if necessary, correct the brake fluid level.
Every two years replace the internal components of the brake master cylinder and caliper, and change the brake fluid.Replace the brake hoses every four years and if cracked or damaged.
27*Throttle grip hous-
ing and cableCheck operation and free play.
Adjust the throttle cable free play
if necessary.
Lubricate the throttle grip housing
and cable.√√√√√
28*Air induction sys-
temCheck the air cut-off valve, reed
valve, and hose for damage.
Replace any damaged parts if
necessary.√√√√√
29*Lights, signals and
switchesCheck operation.
Adjust headlight beam.√√√√√√ NO. ITEM CHECK OR MAINTENANCE JOBODOMETER READING
ANNUAL
CHECK 1000 km
(600 mi)6000 km
(3500 mi)12000 km
(7000 mi)18000 km
(10500 mi)24000 km
(14000 mi)
U27SE0E0.book Page 5 Friday, February 22, 2008 8:54 AM

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)
U27SE0E0.book Page 22 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
6-34
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
6-36
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

SPECIFICATIONS
8-1
8
Dimensions:Overall length:
2055 mm (80.9 in)
Overall width:
845 mm (33.3 in)
Overall height:
1125 mm (44.3 in)
Seat height:
760 mm (29.9 in)
Wheelbase:
1290 mm (50.8 in)
Ground clearance:
140 mm (5.51 in)
Minimum turning radius:
1750 mm (68.9 in)Weight:With oil and fuel:
130.0 kg (287 lb)Engine:Engine type:
Air cooled 4-stroke, SOHC
Cylinder arrangement:
Forward-inclined single cylinder
Displacement:
123.7 cm³
Bore × stroke:
54.0 × 54.0 mm (2.13 × 2.13 in)
Compression ratio:
10.00 :1
Starting system:
Electric starter and kickstarter
Lubrication system:
Wet sump
Engine oil:Type:
SAE 10W-30, SAE 10W-40, SAE 15W-40,
SAE 20W-40 or SAE 20W-50
Recommended engine oil grade:
API service SG type or higher, JASO
standard MA
Engine oil quantity:
Periodic oil change:
1.00 L (1.06 US qt, 0.88 Imp.qt)Air filter:Air filter element:
Dry elementFuel:Recommended fuel:
Regular unleaded gasoline only
Fuel tank capacity:
12.0 L (3.17 US gal, 2.64 Imp.gal)
Fuel reserve amount:
3.0 L (0.79 US gal, 0.66 Imp.gal)
Fuel injection:Throttle body:
Manufacturer:
MIKUNI
Type/quantity:
AC26-6/1Spark plug (s):Manufacturer/model:
NGK/CR6HSA
Spark plug gap:
0.6–0.7 mm (0.024–0.028 in)Clutch:Clutch type:
Wet, multiple-discTransmission:Primary reduction system:
Helical gear
Primary reduction ratio:
68/20 (3.400)
Secondary reduction system:
Chain drive
Secondary reduction ratio:
43/14 (3.071)
Transmission type:
Constant mesh 5-speed
Operation:
Left foot operation
Gear ratio:
1st:
37/14 (2.643)
2nd:
32/18 (1.778)
3rd:
25/19 (1.316)
-20 -10 0
10 20 30
40
50 ˚C
SAE 10W-30
SAE 15W-40SAE 20W-40SAE 20W-50
SAE 10W-40SAE 10W-50
U27SE0E0.book Page 1 Friday, February 22, 2008 8:54 AM