YAMAHA YBR125 2006 Service Manual

PERIODIC MAINTENANCE AND MINOR REPAIR
6-9
6 3. Install the spark plug with the
spark plug wrench, and then tight-
en it to the specified torque.
NOTE:
If a torque wrench is not available when
installing a spark plug, a good estimate
of the correct torque is 1/4–1/2 turn
past finger tight. However, the spark
plug should be tightened to the speci-fied torque as soon as possible.
4. Install the spark plug cap.
EAU37170
Engine oil The engine oil level should be checked
before each ride. In addition, the oil
must be changed at the intervals spec-
ified in the periodic maintenance and
lubrication chart.
To check the engine oil level
1. Place the vehicle on the center-
stand.NOTE:Make sure that the vehicle is positioned
straight up when checking the oil level.
A slight tilt to the side can result in afalse reading.
2. Start the engine, warm it up for
several minutes, and then turn it
off.
3. Wait a few minutes until the oil set-
tles, remove the oil filler cap, wipe
the dipstick clean, insert it back
into the oil filler hole (without
screwing it in), and then remove it
again to check the oil level.
NOTE:
The engine oil should be between theminimum and maximum level marks.
Tightening torque:
Spark plug:
12.5 Nm (1.25 m·kgf, 9.0 ft·lbf)
1. Engine oil filler cap
1. Dipstick
2. Maximum level mark
3. Minimum level mark
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PERIODIC MAINTENANCE AND MINOR REPAIR
6-10
64. If the engine oil is at or below the
minimum level mark, add sufficient
oil of the recommended type to
raise it to the correct level.
5. Insert the dipstick into the oil filler
hole, and then tighten the oil filler
cap.
To change the engine oil
1. Start the engine, warm it up for
several minutes, and then turn it
off.
2. Place an oil pan under the engine
to collect the used oil.
3. Remove the engine oil filler cap
and drain bolt to drain the oil from
the crankcase.4. Install the engine oil drain bolt, and
then tighten it to the specified
torque.
5. Add the specified amount of the
recommended engine oil, and then
install and tighten the engine oil fill-
er cap.
CAUTION:
ECA11620


In order to prevent clutch slip-
page (since the engine oil also
lubricates the clutch), do not
mix any chemical additives. Do
not use oils with a diesel speci-
fication of “CD” or oils of a high-
er quality than specified. In
addition, do not use oils labeled
“ENERGY CONSERVING II” or
higher.


Make sure that no foreign mate-rial enters the crankcase.
6. Start the engine, and then let it idle
for several minutes while checking
it for oil leakage. If oil is leaking, im-
mediately turn the engine off and
check for the cause.
7. Turn the engine off, and then
check the oil level and correct it if
necessary.
1. Engine oil drain bolt
2. Oil pan
Tightening torque:
Engine oil drain bolt:
20 Nm (2.0 m·kgf, 14 ft·lbf)
Recommended engine oil:
See page 8-1.
Oil change quantity:
1.00 L (1.06 US qt) (0.88 Imp.qt)
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PERIODIC MAINTENANCE AND MINOR REPAIR
6-11
6
EAU37120
Cleaning the air filter element The air filter element should be cleaned
at the intervals specified in the periodic
maintenance and lubrication chart.
Clean the air filter element more fre-
quently if you are riding in unusually
wet or dusty areas.
1. Remove panel A. (See page 6-5.)
2. Remove the air filter case cover by
removing the screws.
3. Remove the air filter element.4. Remove the sponge material from
the air filter element.
5. Lightly tap the air filter element to
remove most of the dust and dirt,
and then blow the remaining dirt
out with compressed air on the
mesh side as shown. If the air filter
element is damaged, replace it.6. Clean the sponge material with
solvent, then squeeze the remain-
ing solvent out, and be sure to let
the sponge material dry before in-
stalling it into the air filter element.
If the sponge material is damaged,
replace it.
WARNING
EWA10430
Use only a dedicated parts cleaning
solvent. To avoid the risk of fire or
explosion, do not use gasoline orsolvents with a low flash point.
1. Screw
2. Air filter case cover
1. Sponge material
2. Air filter element
1. Air filter element
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PERIODIC MAINTENANCE AND MINOR REPAIR
6-12
6
CAUTION:
ECA15100
To avoid damaging the sponge ma-
terial, handle it gently and carefully,and do not twist it.
7. Install the sponge material into the
air filter element, and then install
the air filter element into the air fil-
ter case.CAUTION:
ECA10480


Make sure that the air filter ele-
ment is properly seated in the
air filter case.


The engine should never be op-
erated without the air filter ele-
ment installed, otherwise the
piston(s) and/or cylinder(s) maybecome excessively worn.
8. Install the air filter case cover by in-
stalling the screws.
9. Check the hose at the bottom of
the air filter case for accumulated
dust or water, and if necessary,
drain it by removing the clamp, and
then removing the plug.10. Install the plug into the check
hose, and then install the clamp.
11. Install the panel.
EAU21280
Adjusting the carburetor The carburetor is an important part of
the engine and requires very sophisti-
cated adjustment. Therefore, most car-
buretor adjustments should be left to a
Yamaha dealer, who has the neces-
sary professional knowledge and expe-
rience. The adjustment described in the
following section, however, may be ser-
viced by the owner as part of routine
maintenance.CAUTION:
ECA10550
The carburetor has been set and ex-
tensively tested at the Yamaha fac-
tory. Changing these settings
without sufficient technical knowl-
edge may result in poor perfor-mance of or damage to the engine.
1. Clamp
2. Air filter check hose plug
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PERIODIC MAINTENANCE AND MINOR REPAIR
6-13
6
EAU21320
Adjusting the engine idling
speed The engine idling speed must be
checked and, if necessary, adjusted as
follows at the intervals specified in the
periodic maintenance and lubrication
chart.
The engine should be warm before
making this adjustment.NOTE:
The engine is warm when it quickly re-sponds to the throttle.
Check the engine idling speed and, if
necessary, adjust it to specification by
turning the throttle stop screw. To in-
crease the engine idling speed, turn the
screw in direction (a). To decrease the
engine idling speed, turn the screw in
direction (b).
NOTE:
If the specified idling speed cannot be
obtained as described above, have aYamaha dealer make the adjustment.
EAU21370
Adjusting the throttle cable
free play The throttle cable free play should mea-
sure 3.0–7.0 mm (0.12–0.28 in) at the
throttle grip. Periodically check the
throttle cable free play and, if neces-
sary, adjust it as follows.NOTE:The engine idling speed must be cor-
rectly adjusted before checking and ad-justing the throttle cable free play.
1. Loosen the locknut.
1. Throttle stop screw
Engine idling speed:
1300–1500 r/min
1. Throttle cable free play
2. Locknut
3. Adjusting nut
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PERIODIC MAINTENANCE AND MINOR REPAIR
6-14
62. To increase the throttle cable free
play, turn the adjusting nut in direc-
tion (a). To decrease the throttle
cable free play, turn the adjusting
nut in direction (b).
3. Tighten the locknut.
EAU21401
Valve clearance The valve clearance changes with use,
resulting in improper air-fuel mixture
and/or engine noise. To prevent this
from occurring, the valve clearance
must be adjusted by a Yamaha dealer
at the intervals specified in the periodic
maintenance and lubrication chart.
EAU21540
Tires To maximize the performance, durabil-
ity, and safe operation of your motor-
cycle, note the following points
regarding the specified tires.
Tire air pressure
The tire air pressure should be checked
and, if necessary, adjusted before each
ride.
WARNING
EWA10500


The tire air pressure must be
checked and adjusted on cold
tires (i.e., when the temperature
of the tires equals the ambient
temperature).


The tire air pressure must be ad-
justed in accordance with the
riding speed and with the total
weight of rider, passenger, car-
go, and accessories approvedfor this model.
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PERIODIC MAINTENANCE AND MINOR REPAIR
6-15
6
WARNING
EWA11020
Because loading has an enormous
impact on the handling, braking,
performance and safety characteris-
tics of your motorcycle, you should
keep the following precautions in
mind.

NEVER OVERLOAD THE
MOTORCYCLE! Operation of an
overloaded motorcycle may re-
sult in tire damage, loss of con-
trol, or severe injury. Make sure
that the total weight of rider,passenger, cargo, and accesso-
ries does not exceed the speci-
fied maximum load for the
vehicle.


Do not carry along loosely
packed items, which can shift
during a ride.


Securely pack the heaviest
items close to the center of the
motorcycle and distribute the
weight evenly on both sides.


Adjust the suspension and tire
air pressure with regard to the
load.


Check the tire condition and airpressure before each ride.Tire inspection
The tires must be checked before each
ride. If the center tread depth reaches
the specified limit, if the tire has a nail or
glass fragments in it, or if the sidewall is
cracked, have a Yamaha dealer re-
place the tire immediately.
NOTE:The tire tread depth limits may differ
from country to country. Always complywith the local regulations.
Tire air pressure (measured on cold
tires):
0–90 kg (0–198 lb):
Front:
175 kPa (25 psi) (1.75 kgf/cm²)
Rear:
200 kPa (29 psi) (2.00 kgf/cm²)
90–200 kg (198–441 lb):
Front:
175 kPa (25 psi) (1.75 kgf/cm²)
Rear:
280 kPa (41 psi) (2.80 kgf/cm²)
Maximum load*:
200 kg (441 lb)
* Total weight of rider, passenger, car-
go and accessories
1. Tire sidewall
2. Tire tread depth
Minimum tire tread depth (front and
rear):
1.6 mm (0.06 in)
chapter6 Page 15 Friday, January 7, 2005 4:04 PM

PERIODIC MAINTENANCE AND MINOR REPAIR
6-16
6Tire information
This motorcycle is equipped with tube
tires.
WARNING
EWA10460


The front and rear tires should
be of the same make and de-
sign, otherwise the handling
characteristics of the vehicle
cannot be guaranteed.


After extensive tests, only the
tires listed below have been ap-
proved for this model byYamaha Motor Co., Ltd.
WARNING
EWA10570


Have a Yamaha dealer replace
excessively worn tires. Besides
being illegal, operating the
motorcycle with excessively
worn tires decreases riding sta-
bility and can lead to loss of
control.


The replacement of all wheel-
and brake-related parts, includ-
ing the tires, should be left to a
Yamaha dealer, who has the
necessary professional knowl-
edge and experience.


It is not recommended to patch
a punctured tube. If unavoid-
able, however, patch the tube
very carefully and replace it as
soon as possible with a high-quality product.
EAU22000
Cast wheels
WARNING
EWA10610
The wheels on this model are not de-
signed for use with tubeless tires.
Do not attempt to use tubeless tireson this model.
To maximize the performance, durabil-
ity, and safe operation of your motor-
cycle, note the following points
regarding the specified wheels.

The wheel rims should be checked
for cracks, bends, warpage or
damage before each ride. If any
damage is found, have a Yamaha
dealer replace the wheel. Do not
attempt even the smallest repair to
the wheel. A deformed or cracked
wheel must be replaced.


The wheel should be balanced
whenever either the tire or wheel
has been changed or replaced. An
unbalanced wheel can result in
poor performance, adverse han-
dling characteristics, and a short-
ened tire life.
Front tire:
Size:
2.75-18 42P
Manufacturer/model:
CHENG SHIN/SAKURA S-901
PIRELLI/CITY DEMON
Rear tire:
Size:
90/90-18 57P
Manufacturer/model:
CHENG SHIN/SAKURA S-180
PIRELLI/CITY DEMON
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PERIODIC MAINTENANCE AND MINOR REPAIR
6-17
6


Ride conservatively after changing
a tire since the tire must seat itself
on the rim properly. Failure to al-
low proper seating may cause tire
failure, which may result in dam-
age to the motorcycle and injury to
the rider.
EAU22041
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 adjusting bolt in di-
rection (a). To decrease the clutch
lever free play, turn the adjusting
bolt in direction (b).
NOTE:If the specified clutch lever free play
could be obtained as described above,
tighten the locknut and skip the rest of
the procedure, otherwise proceed asfollows.
3. Fully turn the adjusting bolt at the
clutch lever in direction (a) to loos-
en the clutch cable.
4. Loosen the locknut at the crank-
case.
1. Locknut
2. Clutch lever free play adjusting bolt
3. Clutch lever free play
1. Locknut (crankcase)
2. Clutch lever free play adjusting nut (crank-
case)
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PERIODIC MAINTENANCE AND MINOR REPAIR
6-18
65. To increase the clutch lever free
play, turn the adjusting nut in direc-
tion (a). To decrease the clutch le-
ver free play, turn the adjusting nut
in direction (b).
6. Tighten the locknut at the clutch le-
ver and the crankcase.
EAUT1220
Checking the front brake lever
free play The brake lever free play should mea-
sure 0.0–7.0 mm (0.00–0.28 in) as
shown. Periodically check the brake le-
ver free play and, if necessary, have a
Yamaha dealer check the brake sys-
tem.
WARNING
EWA10640
An incorrect brake lever free play in-
dicates a hazardous condition in the
brake system. Do not operate the
motorcycle until the brake system
has been checked or repaired by aYamaha dealer.
EAU22181
Adjusting the brake pedal free
play The brake pedal free play should mea-
sure 20.0–30.0 mm (0.79–1.18 in) at
the brake pedal end as shown. Period-
ically check the brake pedal free play
and, if necessary, adjust it as follows.
To increase the brake pedal free play,
turn the adjusting nut in direction (a). To
decrease the brake pedal free play,
turn the adjusting nut in direction (b).
1. Brake lever free play
1. Brake pedal free play
U3D9E0E0.book Page 18 Saturday, December 25, 2004 11:35 AM