transmission YAMAHA YBR125 2006 Owners Manual

INSTRUMENT AND CONTROL FUNCTIONS
3-2
3
EAU10980
Indicator lights
EAU11030
Turn signal indicator lights “” and
“”
The corresponding indicator light flash-
es when the turn signal switch is
pushed to the left or right.
EAU11060
Neutral indicator light “”
This indicator light comes on when the
transmission is in the neutral position.
EAU11080
High beam indicator light “”
This indicator light comes on when the
high beam of the headlight is switched
on.
EAU11630
Speedometer unit The speedometer unit is equipped with
a speedometer, an odometer and a
tripmeter. The speedometer shows
riding speed. The odometer shows the
total distance traveled. The tripmeter
shows the distance traveled since it
was last set to zero with the reset knob.
The tripmeter can be used to estimate
the distance that can be traveled with a
full tank of fuel. This information will en-
able you to plan future fuel stops.
1. Left turn signal indicator light “”
2. Neutral indicator light “”
3. High beam indicator light “”
4. Right turn signal indicator light “”
1. Speedometer
2. Odometer
3. Tripmeter
4. Tripmeter reset knob
U3D9E0E0.book Page 2 Saturday, December 25, 2004 11:35 AM

INSTRUMENT AND CONTROL FUNCTIONS
3-4
3
EAU12400
Dimmer switch “/”
Set this switch to “” for the high
beam and to “” for the low beam.
EAU12460
Turn signal switch “/”
To signal a right-hand turn, push this
switch to “”. To signal a left-hand
turn, push this switch to “”. When re-
leased, the switch returns to the center
position. To cancel the turn signal
lights, push the switch in after it has re-
turned to the center position.
EAU12500
Horn switch “”
Press this switch to sound the horn.
EAU12710
Start switch “”
Push this switch to crank the engine
with the starter.CAUTION:
ECA10050
See page 5-1 for starting instruc-tions prior to starting the engine.
EAU31640
Clutch lever The clutch lever is located at the left
handlebar grip. To disengage the
clutch, pull the lever toward the handle-
bar grip. To engage the clutch, release
the lever. The lever should be pulled
rapidly and released slowly for smooth
clutch operation.
The clutch lever is equipped with a
clutch switch, which is part of the start-
ing circuit cut-off system. (See page
3-10.)
EAU12870
Shift pedal The shift pedal is located on the left
side of the engine and is used in com-
bination with the clutch lever when
shifting the gears of the 5-speed con-
stant-mesh transmission equipped on
this motorcycle.
1. Clutch lever
1. Shift pedal
U3D9E0E0.book Page 4 Saturday, December 25, 2004 11:35 AM

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
U3D9E0E0.book Page 9 Saturday, December 25, 2004 11:35 AM

INSTRUMENT AND CONTROL FUNCTIONS
3-10
3
EAU15110
Carrier
WARNING
EWA10170


Do not exceed the load limit of 3
kg (6.6 lb) for the carrier.


Do not exceed the maximum
load of 200 kg (441 lb) for the ve-hicle.
EAU15190
Luggage strap holders There are four luggage strap holders
below the rear of the seat.
EAU36950
Starting circuit cut-off system The starting circuit cut-off system (com-
prising the clutch switch and the neutral
switch) prevents starting when the
transmission is in gear and the clutch
lever is not pulled.
Periodically check the operation of the
starting circuit cut-off system according
to the following procedure.
WARNING
EWA10250
If a malfunction is noted, have a
Yamaha dealer check the system be-fore riding.
1. Carrier
1. Luggage strap holder
chapter3 Page 10 Friday, January 7, 2005 4:04 PM

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
U3D9E0E0.book Page 11 Saturday, December 25, 2004 11:35 AM

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.
U3D9E0E0.book Page 1 Saturday, December 25, 2004 11:35 AM

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

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.
EAU16800
Tips for reducing fuel
consumption Fuel consumption depends largely on
your riding style. Consider the following
tips to reduce fuel consumption:

Turn the starter (choke) off as
soon as possible.


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).
EAU16841
Engine break-in There is never a more important period
in the life of your engine than the period
between 0 and 1600 km (1000 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
1600 km (1000 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.
U3D9E0E0.book Page 3 Saturday, December 25, 2004 11:35 AM

PERIODIC MAINTENANCE AND MINOR REPAIR
6-22
6
EAU22760
Drive chain slack The drive chain slack should be
checked before each ride and adjusted
if necessary.
EAU22791
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.
EAU37111
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
adjusting bolt at each end of the
swingarm in direction (a). To loos-
en the drive chain, turn the adjust-
ing bolt at each end of the
swingarm in direction (b), and then
push the rear wheel forward.
NOTE:Using 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
1. Alignment marks
2. Chain puller locknut
3. Drive chain slack adjusting bolt
U3D9E0E0.book Page 22 Saturday, December 25, 2004 11:35 AM

SPECIFICATIONS
8-1
8
Dimensions:Overall length:
1980 mm (78.0 in)
Overall width:
745 mm (29.3 in)
Overall height:
1080 mm (42.5 in)
Seat height:
780 mm (30.7 in)
Wheelbase:
1290 mm (50.8 in)
Ground clearance:
175 mm (6.89 in)
Minimum turning radius:
1750 mm (68.9 in)Weight:With oil and fuel:
120.0 kg (265 lb)Engine:Engine type:
Air cooled 4-stroke, SOHC
Cylinder arrangement:
Forward-inclined single cylinder
Displacement:
123.7 cm³ (7.55 cu.in)
Bore × stroke:
54.0 × 54.0 mm (2.13 × 2.13 in)
Compression ratio:
10.0 :1
Starting system:
Electric starter and kickstarter
Lubrication system:
Wet sump
Engine oil:Type:
SAE10W30 or SAE10W40 or SAE15W40
or SAE20W40 or SAE20W50
Recommended engine oil grade:
API service SE, SF, SG type or higher
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)Carburetor:Manufacturer:
MIKUNIType × quantity:
VM22SH x 1
Spark 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:
45/14 (3.214)
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)
4th:
23/22 (1.045)
5th:
21/24 (0.875)
-20 -10 0
10 20 30
40
50 ˚C
SAE 10W-30
SAE 15W-40SAE 20W-40SAE 20W-50
SAE 10W-40
chapter8 Page 1 Friday, January 7, 2005 4:05 PM