2006 YAMAHA YBR125 engine

INSTRUMENT AND CONTROL FUNCTIONS
3-6
3
NOTE:The fuel tank cap cannot be installed
unless the key is in the lock. In addition,
the key cannot be removed if the cap isnot properly installed and locked.
WARNING
EWA11140
Make sure that the fuel tank cap isproperly installed before riding.
EAU13220
Fuel Make sure that there is sufficient fuel in
the tank. When refueling, be sure to in-
sert the pump nozzle into the fuel tank
filler hole and to fill the tank to the bot-
tom of the filler tube as shown.
WARNING
EWA10880


Do not overfill the fuel tank, oth-
erwise it may overflow when the
fuel warms up and expands.


Avoid spilling fuel on the hot en-gine.
CAUTION:
ECA10070
Immediately wipe off spilled fuel
with a clean, dry, soft cloth, since
fuel may deteriorate painted surfac-es or plastic parts.
EAU13320
CAUTION:
ECA11400
Use only unleaded gasoline. The use
of leaded gasoline will cause severe
damage to internal engine parts,
such as the valves and piston rings,as well as to the exhaust system.
Your Yamaha engine has been de-
signed to use regular unleaded gaso-
line with a research octane number of
91 or higher. If knocking (or pinging) oc-
curs, use a gasoline of a different brand
1. Fuel tank filler tube
2. Fuel level
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)
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INSTRUMENT AND CONTROL FUNCTIONS
3-7
3 or premium unleaded fuel. Use of un-
leaded fuel will extend spark plug life
and reduce maintenance costs.
EAU13431
Catalytic converter This model is equipped with a catalytic
converter in the exhaust system.
WARNING
EWA10860
The exhaust system is hot after op-
eration. Make sure that the exhaust
system has cooled down before do-ing any maintenance work.CAUTION:
ECA10700
The following precautions must be
observed to prevent a fire hazard or
other damages.

Use only unleaded gasoline.
The use of leaded gasoline will
cause unrepairable damage to
the catalytic converter.


Never park the vehicle near pos-
sible fire hazards such as grass
or other materials that easily
burn.


Do not allow the engine to idletoo long.
EAU37210
Fuel cock The fuel cock supplies fuel from the
tank to the carburetor while filtering it al-
so.NOTE:Depending on the model, the positions
indicated on the fuel cock differ asshown in the following illustrations.
The fuel cock has three positions:
“OFF” or “”
With the lever in this position, fuel will
not flow. Always return the lever to this
position when the engine is not running.1. Arrow mark pointing to “OFF” or “”
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INSTRUMENT AND CONTROL FUNCTIONS
3-8
3“ON” or “”
With the lever in this position, fuel flows
to the carburetor. Normal riding is done
with the lever in this position.
“RES” or “”This indicates reserve. If you run out of
fuel while riding, move the lever to this
position. Fill the tank at the first oppor-
tunity. Be sure to set the lever back to
“ON” or “” after refueling!
EAU13590
Starter (choke) lever “” Starting a cold engine requires a richer
air-fuel mixture, which is supplied by
the starter (choke).
Move the lever in direction (a) to turn on
the starter (choke).
Move the lever in direction (b) to turn off
the starter (choke).
1. Arrow mark pointing to “ON” or “”
1. Arrow mark pointing to “RES” or “”
1. Starter (choke) lever “”
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INSTRUMENT AND CONTROL FUNCTIONS
3-9
3
EAU13660
Kickstarter If the engine fails to start by pushing the
start switch, try to start it by using the
kickstarter. To start the engine, fold out
the kickstarter lever, move it down light-
ly with your foot until the gears engage,
and then push it down smoothly but
forcefully. This model is equipped with
a primary kickstarter, allowing the en-
gine to be started in any gear if the
clutch is disengaged. However, shifting
the transmission into the neutral posi-
tion before starting is recommended.
EAU14880
Adjusting the shock absorber
assemblies Each shock absorber assembly is
equipped with a spring preload adjust-
ing ring.CAUTION:
ECA10100
Never attempt to turn an adjusting
mechanism beyond the maximum orminimum settings.
WARNING
EWA10210
Always adjust both shock absorber
assemblies equally, otherwise poor
handling and loss of stability mayresult.
Adjust the spring preload as follows.
To increase the spring preload and
thereby harden the suspension, turn
the adjusting ring on each shock ab-
sorber assembly in direction (a). To de-
crease the spring preload and thereby
soften the suspension, turn the adjust-
ing ring on each shock absorber as-
sembly in direction (b).NOTE:Align the appropriate notch in the ad-
justing ring with the position indicatoron the shock absorber.
1. Kickstarter
1. Spring preload adjusting ring
2. Position indicator
Spring preload setting:
Minimum (soft):
1
Standard:
2
Maximum (hard):
5
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INSTRUMENT AND CONTROL FUNCTIONS
3-11
3
With the engine turned off:
1. Turn the key to “ON”.
2. Shift the transmission into the neutral position.
3. Push the start switch.
Does the engine start?
The neutral switch may be defective.
The motorcycle should not be ridden until
checked by a Yamaha dealer.
4. Turn the engine off.
5. Shift the transmission into gear.
6. Keep the clutch lever pulled.
7. Push the start switch.
Does the engine start?
The clutch switch may be defective.
The motorcycle should not be ridden until
checked by a Yamaha dealer.
NO
NOTE:
a warmed-up engine.
YES
The system is OK. The motorcycle can be ridden.
YES
NO
This check is most reliable if performed with
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PRE-OPERATION CHECKS
4-2
4
EAU15603
Pre-operation check list
ITEM CHECKS PAGE
FuelCheck fuel level in fuel tank.
Refuel if necessary.
Check fuel line for leakage.3-6
Engine oilCheck oil level in engine.
If necessary, add recommended oil to specified level.
Check vehicle for oil leakage.6-9
Front brakeCheck operation.
If soft or spongy, have Yamaha dealer bleed hydraulic system.
Check brake pads for wear.
Replace if necessary.
Check fluid level in reservoir.
If necessary, add recommended brake fluid to specified level.
Check hydraulic system for leakage.6-20, 6-20
Rear brakeCheck operation.
Check pedal free play.
Adjust if necessary.6-20
ClutchCheck operation.
Lubricate cable if necessary.
Check lever free play.
Adjust if necessary.6-17
Throttle gripMake sure that operation is smooth.
Check cable free play.
If necessary, have Yamaha dealer adjust cable free play and lubricate cable and
grip housing.6-13, 6-24
Control cablesMake sure that operation is smooth.
Lubricate if necessary.6-24
Drive chainCheck chain slack.
Adjust if necessary.
Check chain condition.
Lubricate if necessary.6-22, 6-23
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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.
EAU36991
Starting a cold engine In order for the starting 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.WARNING
EWA14160
Before starting the engine, check
the operation of the starting circuit
cut-off system according to the pro-cedure described on page 3-10.
1. Turn the fuel cock lever to “ON” or
“”.
2. Turn the key to “ON”.
3. 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.4. Turn the starter (choke) on and
completely close the throttle. (See
page 3-8.)
5. 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:
ECA11040
For maximum engine life, never ac-
celerate hard when the engine iscold!
6. When the engine is warm, turn the
starter (choke) off.
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OPERATION AND IMPORTANT RIDING POINTS
5-2
5
NOTE:The engine is warm when it responds
normally to the throttle with the starter(choke) turned off.
EAU16640
Starting a warm engine Follow the same procedure as for start-
ing a cold engine with the exception
that the starter (choke) is not required
when the engine is warm.
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
U3D9E0E0.book Page 2 Saturday, December 25, 2004 11:35 AM