2008 YAMAHA YZF-R125 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 and warning lights ............3-2
Tachometer ....................................3-3
Multi-function display ......................3-3
Handlebar switches ........................3-4
Clutch lever .....................................3-5
Shift pedal .......................................3-6
Brake lever .....................................3-6
Brake pedal ....................................3-6
Fuel tank cap ..................................3-7
Fuel .................................................3-7
Catalytic converters ........................3-8
Rider seat .......................................3-9
Anti-theft device housing ................3-9
Sidestand ......................................3-10
Ignition circuit cut-off system ........3-10
PRE-OPERATION CHECKS..............4-1
Pre-operation check list ..................4-2OPERATION 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
MINOR REPAIR................................. 6-1
Owner’s tool kit ............................... 6-1
Periodic maintenance and
lubrication chart .......................... 6-2
Removing and installing the
cowlings and panel ..................... 6-6
Checking the spark plug ................. 6-8
Engine oil and oil filter element ...... 6-9
Coolant ......................................... 6-12
Replacing the air filter element
and cleaning the check hose .... 6-14
Adjusting the engine idling
speed ........................................ 6-14
Adjusting the throttle cable free
play ........................................... 6-15
Valve clearance ............................ 6-16
Tires ............................................. 6-16
Cast wheels .................................. 6-18
Adjusting the clutch lever free
play ........................................... 6-19Checking the front brake lever
free play .................................... 6-20
Adjusting the brake pedal free
play ........................................... 6-20
Checking the front and rear
brake pads ................................ 6-20
Checking the brake fluid level ...... 6-21
Changing the brake fluid .............. 6-22
Drive chain slack .......................... 6-22
Cleaning and lubricating the
drive chain ................................ 6-24
Checking and lubricating the
cables ....................................... 6-24
Checking and lubricating the
throttle grip and cable ............... 6-25
Checking and lubricating the
brake and shift pedals .............. 6-25
Checking and lubricating the
brake and clutch levers ............ 6-26
Checking and lubricating the
sidestand .................................. 6-26
Lubricating the swingarm
pivots ........................................ 6-27
Checking the front fork ................. 6-27
Checking the steering .................. 6-28
Checking the wheel bearings ....... 6-28
Battery ......................................... 6-29
Replacing the fuses ..................... 6-30
Replacing a headlight bulb .......... 6-31
Tail/brake light ............................. 6-31U5D7E0E0.book Page 1 Tuesday, December 18, 2007 10:13 AM

SAFETY INFORMATION
1-2
1 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 conditions.
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 motor-
cycle accidents are the result of head
injuries. 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 abrasions
or lacerations.


Never wear loose-fitting clothes,
otherwise they could catch on the
control levers, footrests, or wheels
and cause injury or an accident.


Never touch the engine or exhaust
system during or after operation.
They become very hot and cancause burns. Always wear protec-
tive clothing that covers your legs,
ankles, and feet.


A passenger should also observe
the above precautions.
Modifications
Modifications made to this motorcycle
not approved by Yamaha, or the re-
moval of original equipment, may ren-
der the motorcycle unsafe for use and
may cause severe personal injury.
Modifications may also make your
motorcycle illegal to use.
Loading and accessories
Adding accessories or cargo to your
motorcycle can adversely affect stabili-
ty and handling if the weight distribution
of the motorcycle is changed. To avoid
the possibility of an accident, use ex-
treme caution when adding cargo or
accessories to your motorcycle. Use
extra care when riding a motorcycle
that has added cargo or accessories.
Here are some general guidelines to
follow if loading cargo or adding acces-
sories to your motorcycle:
U5D7E0E0.book Page 2 Tuesday, December 18, 2007 10:13 AM

SAFETY INFORMATION
1-4
1 tor and may limit control ability,
therefore, such accessories are
not recommended.


Use caution when adding electri-
cal accessories. If electrical acces-
sories exceed the capacity of the
motorcycle’s electrical system, an
electric failure could result, which
could cause a dangerous loss of
lights or engine power.
Gasoline and exhaust gas


GASOLINE IS HIGHLY FLAMMA-
BLE:
Always turn the engine off when
refueling.
Take care not to spill any gaso-
line on the engine or exhaust
system when refueling.
Never refuel while smoking or in
the vicinity of an open flame.


Never start the engine or let it run
for any length of time in a closed
area. The exhaust fumes are poi-
sonous and may cause loss of
consciousness and death within a
short time. Always operate your
motorcycle in an area that has ad-
equate ventilation.


Always turn the engine off before
leaving the motorcycle unattended
and remove the key from the main
switch. When parking the motor-
cycle, note the following:
The engine and exhaust system
may be hot, therefore, park the
motorcycle in a place where pe-
destrians or children are not like-
ly to touch these hot areas.
Do not park the motorcycle on a
slope or soft ground, otherwise it
may fall over.
Do not park the motorcycle near
a flammable source, (e.g., a ker-
osene heater, or near an open
flame), otherwise it could catch
fire.


When transporting the motorcycle
in another vehicle, make sure that
it is kept upright. If the motorcycle
should lean over, gasoline may
leak out of the fuel tank.


If you should swallow any gaso-
line, inhale a lot of gasoline vapor,
or allow gasoline to get into your
eyes, see your doctor immediately.
If any gasoline spills on your skinor clothing, immediately wash the
affected area with soap and water
and change your clothes.
U5D7E0E0.book Page 4 Tuesday, December 18, 2007 10:13 AM

DESCRIPTION
2-2
2
EAU10420
Right view1. Front brake fluid reservoir (page 6-21)
2. Engine oil filter element (page 6-9)
3. Dipstick (page 6-9)
4. Idle adjusting screw (page 6-14)
5. Rear brake fluid reservoir (page 6-21)
6. Brake pedal (page 3-6)
U5D7E0E0.book Page 2 Tuesday, December 18, 2007 10:13 AM

INSTRUMENT AND CONTROL FUNCTIONS
3-1
3
EAU10460
Main switch/steering lock The main switch/steering lock controls
the ignition and lighting systems, and is
used to lock the steering. The various
positions are described below.
EAU36870
ON
All electrical circuits are supplied with
power, the meter lighting, taillight, li-
cense plate light and auxiliary lights
come on, and the engine can be start-
ed. The key cannot be removed.NOTE:The headlight comes on automatically
when the engine is started and stays on
until the key is turned to “OFF”, even ifthe engine stalls.
EAU10660
OFF
All electrical systems are off. The key
can be removed.
EAU10690
LOCK
The steering is locked, and all electrical
systems are off. The key can be re-
moved.
To lock the steering1. Turn the handlebars all the way to
the left or right.
2. Push the key in from the “OFF” po-
sition, and then turn it to “LOCK”
while still pushing it.
3. Remove the key.To unlock the steering
Push the key into the main switch, and
then turn it to “OFF” while still pushing
it.
WARNING
EWA10060
Never turn the key to “OFF” or
“LOCK” while the vehicle is moving,
otherwise the electrical systems will
be switched off, which may result in
loss of control or an accident. Make
sure that the vehicle is stopped be-
fore turning the key to “OFF” or“LOCK”.
1. Push.
2. Turn.
1. Push.
2. Turn.
U5D7E0E0.book Page 1 Tuesday, December 18, 2007 10:13 AM

INSTRUMENT AND CONTROL FUNCTIONS
3-2
3
EAU11003
Indicator and warning lights
EAU11020
Turn signal indicator light“”
This indicator light flashes 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.
EAUM2290
Coolant temperature warning
light“”
This warning light comes on when the
engine overheats. When this occurs,
stop the engine immediately and allow
the engine to cool.
The electrical circuit of the warning light
can be checked by turning the key to
“ON”.
If the warning light does not come on
for a few seconds, then go off, have a
Yamaha dealer check the electrical cir-
cuit.CAUTION:
ECA10020
Do not operate the engine if it isoverheated.
EAU11500
Engine trouble warning light“”
This warning light comes on or flashes
when an electrical circuit monitoring the
engine is defective. When this occurs,
have a Yamaha dealer check the self-
diagnosis system.
The electrical circuit of the warning light
can be checked by turning the key to
“ON”. If the warning light does not come
on for a few seconds, then go off, have
a Yamaha dealer check the electrical
circuit.
1. Neutral indicator light“”
2. Turn signal indicator light“”
3. High beam indicator light“”
4. Engine trouble warning light“”
5. Coolant temperature warning light“”U5D7E0E0.book Page 2 Tuesday, December 18, 2007 10:13 AM

INSTRUMENT AND CONTROL FUNCTIONS
3-3
3
EAU11872
Tachometer The electric tachometer allows the rider
to monitor the engine speed and keep it
within the ideal power range.
When the key is turned to “ON”, the ta-
chometer needle will sweep once
across the r/min range and then return
to zero r/min in order to test the electri-
cal circuit.CAUTION:
ECA10031
Do not operate the engine in the ta-
chometer red zone.Red zone: 10000 r/min and above
EAUM2301
Multi-function display The multi-function display is equipped
with the following:

a speedometer (which shows the
riding speed)


an odometer (which shows the to-
tal distance traveled)


two tripmeters (which show the
distance traveled since they were
last set to zero)


a fuel reserve tripmeter (which
shows the distance traveled since
the fuel level warning light came
on)


a fuel meter
NOTE:

Be sure to turn the key to “ON” be-
fore using the “RESET/ SELECT”
button.


For the U.K. only: To switch the
speedometer and odometer/trip-
meter displays between kilometers
and miles, press the “RESET/SE-
LECT” button for at least eight sec-onds.
Odometer and tripmeter modes
A brief push (less than one second) on
the “RESET/SELECT” button switches
the display between the odometer
mode “ODO” and the tripmeter modes
“TRIP 1” and “TRIP 2” in the following
order:
ODO → TRIP 1 → TRIP 2 → ODO
When approximately 1.6 L (0.42 US
gal)(0.35 Imp.gal) of fuel remains in the
fuel tank, the odometer display will au-
tomatically change to the fuel reserve
tripmeter mode “F-TRIP” and start
counting the distance traveled from that
point, and the last segment of the fuel
meter will start flashing. In that case,
pushing the “RESET/SELECT” button
1. Tachometer
2. Tachometer red zone
1. Multi-function display
2.“RESET/SELECT” button
U5D7E0E0.book Page 3 Tuesday, December 18, 2007 10:13 AM

INSTRUMENT AND CONTROL FUNCTIONS
3-4
3switches the display between the vari-
ous tripmeter and odometer modes in
the following order:
F-TRIP → TRIP 1 → TRIP 2 → ODO →
F-TRIP
To reset a tripmeter, select it by push-
ing the “RESET/SELECT” button briefly
(less than one second), and then push
the button again for at least three sec-
onds while the selected tripmeter is
flashing. If you do not reset the fuel re-
serve tripmeter manually, it will reset it-
self automatically and the display will
return to the prior mode after refueling
and traveling 5 km (3 mi).
Fuel meterThe fuel meter indicates the amount of
fuel in the fuel tank. The display seg-
ments of the fuel meter disappear to-
wards “E” (Empty) as the fuel level
decreases. When the last fuel meter
segment starts flashing, refuel as soon
as possible.
EAU12347
Handlebar switches Left
Right
1. Fuel meter
1. Pass switch “PASS”
2. Dimmer switch“/”
3. Turn signal switch“/”
4. Horn switch“”
1. Engine stop switch“/”
2. Start switch“”
U5D7E0E0.book Page 4 Tuesday, December 18, 2007 10:13 AM