light YAMAHA YBR125 2008 User Guide

PRE-OPERATION CHECKS
4-3
4
Wheels and tiresCheck for damage.
Check tire condition and tread depth.
Check air pressure.
Correct if necessary.6-13, 6-15
Shift pedalMake sure that operation is smooth.
Correct if necessary.—
Brake pedalMake sure that operation is smooth.
Lubricate pedal pivoting point if necessary.6-24
Brake and clutch leversMake sure that operation is smooth.
Lubricate lever pivoting points if necessary.6-23
Centerstand, sidestandMake sure that operation is smooth.
Lubricate pivots if necessary.6-24
Chassis fastenersMake sure that all nuts, bolts and screws are properly tightened.
Tighten if necessary.—
Instruments, lights, signals
and switchesCheck operation.
Correct if necessary.—
Sidestand switchCheck operation of ignition circuit cut-off system.
If system is defective, have Yamaha dealer check vehicle.3-9 ITEM CHECKS PAGE
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OPERATION AND IMPORTANT RIDING POINTS
5-1
5
EAU15950
WARNING
EWA10270


Become thoroughly familiar
with all operating controls and
their functions before riding.
Consult a Yamaha dealer re-
garding any control or function
that you do not thoroughly un-
derstand.


Never start the engine or oper-
ate it in a closed area for any
length of time. Exhaust fumes
are poisonous, and inhaling
them can cause loss of con-
sciousness and death within a
short time. Always make sure
that there is adequate ventila-
tion.


Before starting out, make sure
that the sidestand is up. If the
sidestand is not raised com-
pletely, it could contact the
ground and distract the opera-
tor, resulting in a possible lossof control.
EAU45310
NOTE:This model is equipped with a lean an-
gle sensor to stop the engine in case of
a turnover. To start the engine after a
turnover, be sure to turn the main
switch to “OFF” and then to “ON”. Fail-
ing to do so will prevent the engine from
starting even though the engine willcrank when pushing the start switch.
EAU43181
Starting the engine In order for the ignition circuit cut-off
system to enable starting, one of the
following conditions must be met:

The transmission is in the neutral
position.


The transmission is in gear with
the clutch lever pulled and the sid-
estand up.WARNING
EWA10290


Before starting the engine,
check the function of the igni-
tion circuit cut-off system ac-
cording to the procedure
described on page 3-10.


Never ride with the sidestanddown.
1. Turn the key to “ON”.
2. Shift the transmission into the neu-
tral position.
NOTE:When the transmission is in the neutral
position, the neutral indicator light
should be on, otherwise have a
Yamaha dealer check the electrical cir-cuit.
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OPERATION AND IMPORTANT RIDING POINTS
5-2
53. Start the engine by pushing the
start switch or by pushing the kick-
starter lever down.
NOTE:If the engine fails to start when using
the start switch, release it, wait a few
seconds, and then try again. Each
starting attempt should be as short as
possible to preserve the battery. Do not
crank the engine more than 10 seconds
on any one attempt. If the engine does
not start with the starter motor, try usingthe kickstarter.CAUTION:
ECA11370
The engine trouble warning light
should come on when the key is
turned to “ON”, and then go off after
a few seconds. If the engine trouble
warning light comes on or flashes
after starting, immediately stop the
engine, and have a Yamaha dealercheck the self-diagnosis system.
CAUTION:
ECA11040
For maximum engine life, never ac-
celerate hard when the engine iscold!
EAU16671
Shifting Shifting gears lets you control the
amount of engine power available for
starting off, accelerating, climbing hills,
etc.
The gear positions are shown in the il-
lustration.NOTE:To shift the transmission into the neu-
tral position, press the shift pedal down
repeatedly until it reaches the end of itstravel, and then slightly raise it.1. Shift pedal
2. Neutral position
U27SE0E0.book Page 2 Friday, February 22, 2008 8:54 AM

OPERATION AND IMPORTANT RIDING POINTS
5-3
5
CAUTION:
ECA10260


Even with the transmission in
the neutral position, do not
coast for long periods of time
with the engine off, and do not
tow the motorcycle for long dis-
tances. The transmission is
properly lubricated only when
the engine is running. Inade-
quate lubrication may damage
the transmission.


Always use the clutch while
changing gears to avoid damag-
ing the engine, transmission,
and drive train, which are not
designed to withstand theshock of forced shifting.
EAU16810
Tips for reducing fuel con-
sumption Fuel consumption depends largely on
your riding style. Consider the following
tips to reduce fuel consumption:

Shift up swiftly, and avoid high en-
gine speeds during acceleration.


Do not rev the engine while shifting
down, and avoid high engine
speeds with no load on the engine.


Turn the engine off instead of let-
ting it idle for an extended length of
time (e.g., in traffic jams, at traffic
lights or at railroad crossings).
EAU16830
Engine break-in There is never a more important period
in the life of your engine than the period
between 0 and 1000 km (600 mi). For
this reason, you should read the follow-
ing material carefully.
Since the engine is brand new, do not
put an excessive load on it for the first
1000 km (600 mi). The various parts in
the engine wear and polish themselves
to the correct operating clearances.
During this period, prolonged full-throt-
tle operation or any condition that might
result in engine overheating must be
avoided.
EAU37250
0–500 km (0–300 mi)
Avoid prolonged operation above 6000
r/min.
After every hour of operation, stop the
engine, and then let it cool for five to ten
minutes.
Vary the engine speed from time to
time. Do not operate the engine at one
set throttle position.
U27SE0E0.book Page 3 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
6-8
6To check the spark plug
1. Check that the porcelain insulator
around the center electrode of the
spark plug is a medium-to-light tan
(the ideal color when the vehicle is
ridden normally).
NOTE:
If the spark plug shows a distinctly dif-
ferent color, the engine could be oper-
ating improperly. Do not attempt to
diagnose such problems yourself. In-
stead, have a Yamaha dealer checkthe vehicle.2. Check the spark plug for electrode
erosion and excessive carbon or
other deposits, and replace it if
necessary.
To install the spark plug
1. Measure the spark plug gap with a
wire thickness gauge and, if nec-
essary, adjust the gap to specifica-
tion.2. Clean the surface of the spark plug
gasket and its mating surface, and
then wipe off any grime from the
spark plug threads.
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.
1. Spark plug wrench
Specified spark plug:
NGK/CR6HSA1. Spark plug gapSpark plug gap:
0.6–0.7 mm (0.024–0.028 in)
Tightening torque:
Spark plug:
12.5 Nm (1.25 m·kgf, 9.0 ft·lbf)
U27SE0E0.book Page 8 Friday, February 22, 2008 8:54 AM

PERIODIC MAINTENANCE AND MINOR REPAIR
6-9
6
EAU37171
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.4. 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.1. Engine oil filler cap
1. Dipstick
2. Maximum level mark
3. Minimum level mark
1. Engine oil drain bolt
2. Oil pan
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PERIODIC MAINTENANCE AND MINOR REPAIR
6-11
6 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.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.
1. Air filter element
2. Sponge material
2
1
1. Air filter element
1
U27SE0E0.book Page 11 Friday, February 22, 2008 8:54 AM

PERIODIC MAINTENANCE AND MINOR REPAIR
6-17
6
EAUT1221
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
EWA10641
An incorrect brake lever free play in-
dicates a hazardous condition in the
brake system. Do not operate the ve-
hicle until the brake system has
been checked or repaired by aYamaha dealer.
EAU39812
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 at the brake rod in
direction (a). To decrease the brake
pedal free play, turn the adjusting nut in
direction (b).
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.
1. Brake lever free play
1. Brake pedal free play
1. Brake pedal free play adjusting nut
1(a)
(b)
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PERIODIC MAINTENANCE AND MINOR REPAIR
6-18
6
EAU44820
Checking the shift pedal The operation of the shift pedal should
be checked before each ride. If opera-
tion is not smooth, have a Yamaha
dealer check the vehicle.
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 B. (See page 6-6.)
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. Rear brake light switch
2. Rear brake light switch adjusting nut
U27SE0E0.book Page 18 Friday, February 22, 2008 8:54 AM