2014 YAMAHA YBR125 engine

TABLE OF CONTENTSSAFETY INFORMATION.................. 1-1
DESCRIPTION .................................. 2-1
Left view ......................................... 2-1
Right view ....................................... 2-2
Controls and instruments ............... 2-3
INSTRUMENT AND CONTROL
FUNCTIONS ...................................... 3-1
Main switch/steering lock............... 3-1
Indicator lights and warning light ... 3-2
Speedometer unit ........................... 3-3
Tachometer .................................... 3-3
Self-diagnosis device ..................... 3-3
Fuel gauge ...................................... 3-4
Handlebar switches ........................ 3-4
Clutch lever .................................... 3-5
Shift pedal ...................................... 3-5
Brake lever...................................... 3-5
Brake pedal .................................... 3-6
Fuel tank cap .................................. 3-6
Fuel ................................................. 3-7
Catalytic converters........................ 3-8
Kickstarter ...................................... 3-9
Adjusting the shock absorber assemblies .................................. 3-9
Carrier ........................................... 3-10
Sidestand ..................................... 3-10
Ignition circuit cut-off system ....... 3-11 FOR YOUR SAFETY –
PRE-OPERATION CHECKS
............. 4-1
OPERATION AND IMPORTANT
RIDING POINTS ................................ 5-1
Starting the engine .......................... 5-1
Shifting ............................................ 5-2
Tips for reducing fuel consumption ................................ 5-3
Engine break-in ............................... 5-3
Parking ............................................ 5-4
PERIODIC MAINTENANCE AND
ADJUSTMENT ................................... 6-1
Owner’s tool kit ............................... 6-2
Periodic maintenance chart for the emission control system .............. 6-3
General maintenance and lubrication chart ........................... 6-4
Removing and installing panels ...... 6-7
Checking the spark plug ................. 6-8
Engine oil....................................... 6-10
Cleaning the air filter element ....... 6-11
Checking the engine idling
speed ......................................... 6-13
Checking the throttle grip free
play ............................................ 6-13
Valve clearance ............................. 6-14
Tires .............................................. 6-14
Cast wheels................................... 6-16 Adjusting the clutch lever free
play ............................................ 6-16
Checking the brake lever free play ............................................ 6-17
Adjusting the brake pedal free
play ............................................ 6-18
Checking the shift pedal ............... 6-18
Brake light switches ..................... 6-19
Checking the front brake pads and rear brake shoes ............... 6-19
Checking the brake fluid level ...... 6-20
Changing the brake fluid .............. 6-21
Drive chain slack........................... 6-21
Cleaning and lubricating the drive
chain.......................................... 6-23
Checking and lubricating the cables ........................................ 6-24
Checking and lubricating the throttle grip and cable ............... 6-24
Checking and lubricating the
brake and clutch levers ............. 6-24
Checking and lubricating the brake pedal ............................... 6-25
Checking and lubricating the centerstand and sidestand........ 6-25
Lubricating the swingarm
pivots......................................... 6-26
Checking the front fork ................. 6-26
Checking the steering................... 6-27
Checking the wheel bearings ....... 6-27
Battery .......................................... 6-28U51DE1E0.book Page 1 Thursday, August 29, 2013 4:41 PM

SAFETY INFORMATION
1-2
1

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 mo-
torcycle to other qualified oper-
ators.
• 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
operator. A typical error made by
the operator is veering wide on a
turn due to excessive speed or un-
dercornering (insufficient lean an-
gle for the speed).
• Always obey the speed limit and never travel faster than warrant-
ed by road and traffic condi-
tions. • Always signal before turning or
changing lanes. Make sure that
other motorists can see you.
 The posture of the operator and
passenger is important for proper
control.
• The operator should keep both hands on the handlebar and
both feet on the operator foot-
rests during operation to main-
tain control of the motorcycle.
• The passenger should always hold onto the operator, the seat
strap or grab bar, if equipped,
with both hands and keep both
feet on the passenger footrests.
Never carry a passenger unless
he or she can firmly place both
feet on the passenger footrests.
 Never ride under the influence of
alcohol or other drugs.
 This motorcycle is designed for
on-road use only. It is not suitable
for off-road use. Protective Apparel
The majority of fatalities from motorcy-
cle accidents are the result of head in-
juries. The use of a safety helmet is the
single most critical factor in the pre-
vention or reduction of head injuries.
 Always wear an approved helmet.
 Wear a face shield or goggles.
Wind in your unprotected eyes
could contribute to an impairment
of vision that could delay seeing a
hazard.
 The use of a jacket, heavy boots,
trousers, gloves, etc., is effective
in preventing or reducing abra-
sions or lacerations.
 Never wear loose-fitting clothes,
otherwise they could catch on the
control levers, footrests, or wheels
and cause injury or an accident.
 Always wear protective clothing
that covers your legs, ankles, and
feet. The engine or exhaust sys-
tem become very hot during or af-
ter operation and can cause
burns.
 A passenger should also observe
the above precautions.
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SAFETY INFORMATION
1-3
1Avoi
d Car bon Monoxi de Poisonin g
All engine exhaust contains carbon
monoxide, a deadly gas. Breathing
carbon monoxide can cause head-
aches, dizziness, drowsiness, nausea,
confusion, and eventually death.
Carbon Monoxide is a colorless, odor-
less, tasteless gas which may be pres-
ent even if you do not see or smell any
engine exhaust. Deadly levels of car-
bon monoxide can collect rapidly and
you can quickly be overcome and un-
able to save yourself. Also, deadly lev-
els of carbon monoxide can linger for
hours or days in enclosed or poorly
ventilated areas. If you experience any
symptoms of carbon monoxide poi-
soning, leave the area immediately, get
fresh air, and SEEK MEDICAL TREAT-
MENT.  Do not run engine indoors. Even if
you try to ventilate engine exhaust
with fans or open windows and
doors, carbon monoxide can rap-
idly reach dangerous levels.
 Do not run engine in poorly venti-
lated or partially enclosed areas
such as barns, garages, or car-
ports. 
Do not run engine outdoors where
engine exhaust can be drawn into
a building through openings such
as windows and doors.
Loa din g
Adding accessories or cargo to your
motorcycle can adversely affect stabil-
ity and handling if the weight distribu-
tion of the motorcycle is changed. To
avoid the possibility of an accident, use
extreme caution when adding cargo or
accessories to your motorcycle. Use
extra care when riding a motorcycle
that has added cargo or accessories.
Here, along with the information about
accessories below, are some general
guidelines to follow if loading cargo to
your motorcycle:
The total weight of the operator, pas-
senger, accessories and cargo must
not exceed the maximum load limit.
Operation of an overloa ded vehicle
coul d cause an acci dent. When loading within this weight limit,
keep the following in mind:
 Cargo and accessory weight
should be kept as low and close to
the motorcycle as possible. Se-
curely pack your heaviest items as
close to the center of the vehicle
as possible and make sure to dis-
tribute the weight as evenly as
possible on both sides of the mo-
torcycle to minimize imbalance or
instability.
 Shifting weights can create a sud-
den imbalance. Make sure that
accessories and cargo are se-
curely attached to the motorcycle
before riding. Check accessory
mounts and cargo restraints fre-
quently.
• Properly adjust the suspension for your load (suspension-ad-
justable models only), and
check the condition and pres-
sure of your tires.
• Never attach any large or heavy items to the handlebar, front
fork, or front fender. These
items, including such cargo as
sleeping bags, duffel bags, or
Maximum loa d:
194 kg (428 lb)
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SAFETY INFORMATION
1-5
1operator and may limit control
ability, therefore, such accesso-
ries are not recommended.
 Use caution when adding electri-
cal accessories. If electrical ac-
cessories exceed the capacity of
the motorcycle’s electrical sys-
tem, an electric failure could re-
sult, which could cause a
dangerous loss of lights or engine
power.
Aftermarket Tires an d Rims
The tires and rims that came with your
motorcycle were designed to match
the performance capabilities and to
provide the best combination of han-
dling, braking, and comfort. Other
tires, rims, sizes, and combinations
may not be appropriate. Refer to page
6-14 for tire specifications and more in-
formation on replacing your tires.
Transportin g the Motorcycle
Be sure to observe following instruc-
tions before transporting the motorcy-
cle in another vehicle.  Remove all loose items from the
motorcycle. 
Check that the fuel cock (if
equipped) is in the “OFF” position
and that there are no fuel leaks.
 Point the front wheel straight
ahead on the trailer or in the truck
bed, and choke it in a rail to pre-
vent movement.
 Shift the transmission in gear (for
models with a manual transmis-
sion).
 Secure the motorcycle with tie-
downs or suitable straps that are
attached to solid parts of the mo-
torcycle, such as the frame or up-
per front fork triple clamp (and not,
for example, to rubber-mounted
handlebars or turn signals, or
parts that could break). Choose
the location for the straps carefully
so the straps will not rub against
painted surfaces during transport.
 The suspension should be com-
pressed somewhat by the tie-
downs, if possible, so that the mo-
torcycle will not bounce exces-
sively during transport.
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DESCRIPTION
2-1
2
EAU10411
Left view
1
2,3,4
6
7
5
1. Headlight (page 6-30)
2. Fuse (page 6-29)
3. Battery (page 6-28)
4. Owner’s tool kit (page 6-2)
5. Shock absorber assembly spring preload adjusting ring (page 3-9)
6. Engine oil drain bolt (page 6-10)
7. Shift pedal (page 3-5)
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DESCRIPTION
2-2
2
EAU10421
Right view
1
2
3
4
5
6
1. Carrier (page 3-10)
2. Air filter element (page 6-11)
3. Engine oil filler cap (page 6-10)
4. Brake pedal (page 3-6)
5. Kickstarter (page 3-9)
6. Shock absorber assembly spring preload adjusting ring (page 3-9)U51DE1E0.book Page 2 Thursday, August 29, 2013 4:41 PM

INSTRUMENT AND CONTROL FUNCTIONS
3-1
3
EAU10462
Main switch/steering lockThe main switch/steering lock controls
the ignition and lighting systems, and is
used to lock the steering. The various
positions are described below.
EAU33591
ON
All electrical circuits are supplied with
power; the meter lighting, taillight and
auxiliary light come on, and the engine
can be started. The key cannot be re-
moved.TIPThe headlight comes on automatically
when the engine is started and stays
on until the key is turned to “OFF”,
even if the engine stalls.
EAU10662
OFF
All electrical systems are off. The key
can be removed.
WARNING
EWA10062
Never turn the key to “OFF” or
“LOCK” while the vehicle is movin g.
Otherwise the electrical systems will
b e switche d off, which may result in
loss of control or an acci dent.
EAU43142
LOCK
The steering is locked, and all electrical
systems are off. The key can be re-
moved. To lock the steering
1. Turn the handlebars all the way to
the left.
2. Push the key in from the “OFF” position, and then turn it to
“LOCK” while still pushing it.
3. Remove the key.
LOCK
IGNITION
OFFON
PUSHON
OFF
LOCK
1. Push.
2. Turn.
LOCK
OFF
LOCK
OFF
12
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INSTRUMENT AND CONTROL FUNCTIONS
3-2
3
To unlock the steering
Insert the key and turn it to “OFF”.
EAU11008
In
dicator li ghts an d warnin g
lig ht
EAU11031
Turn si gnal in dicator li ghts “ ”
an d“”
The corresponding indicator light
flashes when the turn signal switch is
pushed to the left or right.
EAU11061
Neutral in dicator li ght “ ”
This indicator light comes on when the
transmission is in the neutral position.
EAU11081
Hi gh beam in dicator li ght “ ”
This indicator light comes on when the
high beam of the headlight is switched
on.
EAU11506
En gine trou ble warnin g li ght “ ”
This warning light comes on or flashes
if a problem is detected in the electrical
circuit monitoring the engine. If this oc-
curs, have a Yamaha dealer check the
self-diagnosis system. (See page 3-3
for an explanation of the self-diagnosis
device.)
The electrical circuit of the warning
light can be checked by turning the key
to “ON”. The warning light should
come on for a few seconds, and then
go off.
If the warning light does not come on
initially when the key is turned to “ON”,
or if the warning light remains on, have
a Yamaha dealer check the electrical
circuit.
1. Turn.
LOCKOFF
1
1. Left turn signal indicator light “ ”
2. Neutral indicator light “ ”
3. Engine trouble warning light “ ”
4. High beam indicator light “ ”
5. Right turn signal indicator light “ ”
5
4
3
2
1
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