2008 YAMAHA YZF-R125 check engine

PERIODIC MAINTENANCE AND MINOR REPAIR
6-28
6
EAU23280
Checking the steering Worn or loose steering bearings may
cause danger. Therefore, the operation
of the steering must be checked as fol-
lows at the intervals specified in the pe-
riodic maintenance and lubrication
chart.
1. Place a stand under the engine to
raise the front wheel off the
ground.
WARNING
EWA10750
Securely support the vehicle so thatthere is no danger of it falling over.
2. Hold the lower ends of the front
fork legs and try to move them for-
ward and backward. If any free
play can be felt, have a Yamaha
dealer check or repair the steering.
EAU23290
Checking the wheel bearings The front and rear wheel bearings must
be checked at the intervals specified in
the periodic maintenance and lubrica-
tion chart. If there is play in the wheel
hub or if the wheel does not turn
smoothly, have a Yamaha dealer check
the wheel bearings.
U5D7E0E0.book Page 28 Tuesday, December 18, 2007 10:13 AM

PERIODIC MAINTENANCE AND MINOR REPAIR
6-32
6
EAUM2200
Replacing the license plate
light bulb 1. Remove the socket (together with
the bulb) by pulling it out.
2. Remove the defective bulb by pull-
ing it out.
3. Insert a new bulb into the socket.
4. Install the socket (together with the
bulb) by pushing it in.
EAU43230
Replacing an auxiliary light
bulb This model is equipped with two auxil-
iary lights. If an auxiliary light bulb burns
out, replace it as follows.
1. Remove the socket (together with
the bulb) by pulling it out.
2. Remove the defective bulb by pull-
ing it out.
3. Insert a new bulb into the socket.
4. Install the socket (together with the
bulb) by pushing it in.
EAU24350
Supporting the motorcycle Since this model is not equipped with a
centerstand, follow these precautions
when removing the front and rear
wheel or performing other maintenance
requiring the motorcycle to stand up-
right. Check that the motorcycle is in a
stable and level position before starting
any maintenance. A strong wooden
box can be placed under the engine for
added stability.
To service the front wheel
1. Stabilize the rear of the motorcycle
by using a motorcycle stand or, if
an additional motorcycle stand is
not available, by placing a jack un-
der the frame in front of the rear
wheel.
2. Raise the front wheel off the
ground by using a motorcycle
stand.
To service the rear wheel
Raise the rear wheel off the ground by
using a motorcycle stand or, if a motor-
cycle stand is not available, by placing
1. License plate light bulb
1. Auxiliary light bulb
U5D7E0E0.book Page 32 Tuesday, December 18, 2007 10:13 AM

PERIODIC MAINTENANCE AND MINOR REPAIR
6-37
6
EAUM2440
Troubleshooting charts Starting problems or poor engine performance
WARNING
EWA10840
Keep away open flames and do not smoke while checking or working on the fuel system.
Check the fuel level in
the fuel tank.1. Fuel
There is enough fuel.
There is no fuel.
Check the compression.
Supply fuel.
Operate the electric starter.2. Compression
There is compression.
There is no compression.
Check the ignition.
Have a Yamaha dealer
check the vehicle.
Remove the spark plug
and check the electrodes.3. Ignition
Wet
Dry
Wipe off with a dry cloth and correct the
spark plug gap, or replace the spark plug.
Have a Yamaha dealer check the vehicle.The engine does not start.
Check the battery.
Operate the electric starter.
Operate the electric starter.4. Battery
The engine turns over
quickly.
The engine turns over
slowly.The battery is good.
Check the electrolyte and battery
lead connections, and charge the
battery if necessary.The engine does not start.
Have a Yamaha dealer
check the vehicle.
The engine does not start.
Check the compression.
U5D7E0E0.book Page 37 Tuesday, December 18, 2007 10:13 AM

PERIODIC MAINTENANCE AND MINOR REPAIR
6-38
6Engine overheating
WARNING
EWA10400


Do not remove the radiator cap when the engine and radiator are hot. Scalding hot fluid and steam may be
blown out under pressure, which could cause serious injury. Be sure to wait until the engine has cooled.


After removing the radiator cap retaining bolt, place a thick rag, like a towel, over the radiator cap, and then
slowly rotate the cap counterclockwise to the detent to allow any residual pressure to escape. When the hissingsound has stopped, press down on the cap while turning it counterclockwise, and then remove the cap.
NOTE:If coolant is not available, tap water can be temporarily used instead, provided that it is changed to the recommended coolantas soon as possible.
Wait until the
engine has cooled.
Check the coolant level in the
reservoir and radiator.
The coolant level
is OK.The coolant level is low.
Check the cooling system
for leakage.
Have a Yamaha dealer checkand repair the cooling system.Add coolant. (See NOTE.)
Start the engine. If the engine overheats again,
have a
Yamaha dealer check
and repair the cooling system.
There is
leakage.
There is
no leakage.
U5D7E0E0.book Page 38 Tuesday, December 18, 2007 10:13 AM

MOTORCYCLE CARE AND STORAGE
7-4
73. Perform the following steps to pro-
tect the cylinder, piston rings, etc.
from corrosion.
a. Remove the spark plug cap
and spark plug.
b. Pour a teaspoonful of engine oil
into the spark plug bore.
c. Install the spark plug cap onto
the spark plug, and then place
the spark plug on the cylinder
head so that the electrodes are
grounded. (This will limit spark-
ing during the next step.)
d. Turn the engine over several
times with the starter. (This will
coat the cylinder wall with oil.)
e. Remove the spark plug cap
from the spark plug, and then
install the spark plug and the
spark plug cap.
WARNING
EWA10950
To prevent damage or injury from
sparking, make sure to ground the
spark plug electrodes while turningthe engine over.4. Lubricate all control cables and the
pivoting points of all levers and
pedals as well as of the side-
stand/centerstand.
5. Check and, if necessary, correct
the tire air pressure, and then lift
the motorcycle so that both of its
wheels are off the ground. Alterna-
tively, turn the wheels a little every
month in order to prevent the tires
from becoming degraded in one
spot.
6. Cover the muffler outlet with a
plastic bag to prevent moisture
from entering it.
7. Remove the battery and fully
charge it. Store it in a cool, dry
place and charge it once a month.
Do not store the battery in an ex-
cessively cold or warm place [less
than 0 °C (30 °F) or more than 30
°C (90 °F)]. For more information
on storing the battery, see page
6-29.
NOTE:Make any necessary repairs beforestoring the motorcycle.
U5D7E0E0.book Page 4 Tuesday, December 18, 2007 10:13 AM

INDEXAAir filter element and check hose,
replacing and cleaning........................ 6-14
Anti-theft device housing......................... 3-9
Auxiliary light bulb, replacing ................ 6-32BBattery................................................... 6-29
Brake and clutch levers, checking and
lubricating ........................................... 6-26
Brake and shift pedals, checking and
lubricating ........................................... 6-25
Brake fluid, changing ............................ 6-22
Brake fluid level, checking .................... 6-21
Brake lever .............................................. 3-6
Brake pedal ............................................. 3-6
Brake pedal free play, adjusting............ 6-20CCables, checking and lubricating .......... 6-24
Care ........................................................ 7-1
Catalytic converters ................................ 3-8
Clutch lever ............................................. 3-5
Clutch lever free play, adjusting ............ 6-19
Coolant.................................................. 6-12
Coolant temperature warning light .......... 3-2
Cowlings and panel, removing and
installing................................................ 6-6DDimmer switch ........................................ 3-5
Drive chain, cleaning and lubricating .... 6-24
Drive chain slack ................................... 6-22EEngine break-in ....................................... 5-3
Engine idling speed............................... 6-14
Engine oil and oil filter element ............... 6-9Engine stop switch.................................. 3-5
Engine trouble warning light ................... 3-2
FFront and rear brake pads, checking .... 6-20
Front brake lever free play, checking ... 6-20
Front fork, checking .............................. 6-27
Fuel......................................................... 3-7
Fuel consumption, tips for reducing........ 5-3
Fuel tank cap .......................................... 3-7
Fuses, replacing ................................... 6-30HHandlebar switches ................................ 3-4
Headlight bulb, replacing ...................... 6-31
High beam indicator light ........................ 3-2
Horn switch ............................................. 3-5IIdentification numbers ............................ 9-1
Ignition circuit cut-off system ................ 3-10
Indicator and warning lights .................... 3-2KKey identification number ....................... 9-1LLicense plate light bulb, replacing ........ 6-32MMain switch/steering lock........................ 3-1
Matte color, caution ................................ 7-1
Model label ............................................. 9-2
Multi-function display .............................. 3-3NNeutral indicator light .............................. 3-2PParking ................................................... 5-4
Part locations .......................................... 2-1
Pass switch............................................. 3-5Periodic maintenance and lubrication
chart ...................................................... 6-2
Pre-operation check list........................... 4-2
RRider seat ................................................ 3-9SSafety information ................................... 1-1
Shifting .................................................... 5-2
Shift pedal ............................................... 3-6
Sidestand .............................................. 3-10
Sidestand, checking and lubricating...... 6-26
Spark plug, checking ............................... 6-8
Specifications .......................................... 8-1
Starting the engine .................................. 5-1
Start switch.............................................. 3-5
Steering, checking................................. 6-28
Storage.................................................... 7-3
Supporting the motorcycle .................... 6-32
Swingarm pivots, lubricating ................. 6-27TTachometer ............................................. 3-3
Tail/brake light ....................................... 6-31
Throttle cable free play, adjusting ......... 6-15
Throttle grip and cable, checking and
lubricating ........................................... 6-25
Tires ...................................................... 6-16
Tool kit..................................................... 6-1
Troubleshooting .................................... 6-36
Troubleshooting charts.......................... 6-37
Turn signal indicator light ........................ 3-2
Turn signal light bulb, replacing ............ 6-31
Turn signal switch ................................... 3-5VValve clearance..................................... 6-16
U5D7E0E0.book Page 1 Tuesday, December 18, 2007 10:13 AM