2012 YAMAHA YFM250R-W check engine

8-19
8 4. Check the gasket for damage, and replace it if
necessary.
5. Make sure the gasket is properly positioned,
then insert the tailpipe into the muffler and
align the bolt holes.6. Install the bolts and tighten them to the speci-
fied torque.
WARNING
EWB02340Do not start the engine when cleaning the
spark arrester, otherwise it could cause injury
to the eyes, burns, carbon monoxide poison-
1. Tailpipe
2. Spark arrester
2 1
1. Gasket
2. Tailpipe
3. Tailpipe boltTightening torque:
Tailpipe bolt:
11 Nm (1.1 m·kgf, 8.0 ft·lbf)
1 2
33
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8-20
8ing, possibly leading to death, and start a fire.
Always let the exhaust system cool prior to
touching exhaust components.
EBU23940Adjusting the carburetor The carburetor should be checked and, if neces-
sary, adjusted at the intervals specified in the peri-
odic maintenance and lubrication chart. The
carburetor is an important part of the engine and
requires very sophisticated adjustment. Therefore,
most carburetor adjustments should be left to a
Yamaha dealer, who has the necessary profes-
sional knowledge and experience. The adjustment
described in the following section, however, may
be performed by the owner as part of routine main-
tenance.NOTICEECB00480The carburetor has been set and extensively
tested at the Yamaha factory. Changing these
settings without sufficient technical knowl-
edge may result in poor performance of or
damage to the engine.
EBU24000Adjusting the engine idling speed The engine idling speed must be checked and, if
necessary, adjusted as follows at the intervals
specified in the periodic maintenance and lubrica-
tion chart.TIPA diagnostic tachometer is needed to make this
adjustment.1. Start the engine and warm it up.TIPThe engine is warm when it quickly responds to the
throttle.2. Attach the tachometer to the spark plug lead.
3. Check the engine idling speed and, if neces-
sary, adjust it to specification by turning the
throttle stop screw at the carburetor. To in-
crease the engine idling speed, turn the throt-
tle stop screw in direction (a), and to decrease
it, turn the screw in direction (b).
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8-21
8
TIPIf the specified idling speed cannot be obtained as
described above, have a Yamaha dealer make the
adjustment.EBU24047Adjusting the throttle lever free play The throttle lever free play should be checked and,
if necessary, adjusted at the intervals specified in
the periodic maintenance and lubrication chart.The throttle lever free play should measure 2.0–
4.0 mm (0.08–0.16 in) as shown. Periodically
check the throttle lever free play and, if necessary,
adjust it as follows.
TIPThe engine idling speed must be checked, and ad-
justed if necessary, before adjusting the throttle le-
ver free play.1. Slide the rubber cover back.
2. Loosen the locknut.
3. To increase the throttle lever free play, turn
the throttle lever free play adjusting bolt in di-
rection (a). To decrease the throttle lever free
play, turn the adjusting bolt in direction (b).
1. Throttle stop screwEngine idling speed:
1600–1700 r/min
1
(a)
(b)
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8-22
8
4. Tighten the locknut.
5. Slide the rubber cover to its original position.
EBU24060Valve clearance The valve clearance changes with use, resulting in
improper air-fuel mixture and/or engine noise. To
prevent this from occurring, the valve clearance
must be adjusted by a Yamaha dealer at the inter-
vals specified in the periodic maintenance and lu-
brication chart.
EBU29601Brakes Replacement of brake components requires pro-
fessional knowledge. Brake service should be per-
formed by a Yamaha dealer.
WARNING
EWB02571Operating with improperly serviced or adjust-
ed brakes could lead to a loss in braking ability
and an accident.EBU24130Checking the front and rear brake pads The front and rear brake pads must be checked for
wear at the intervals specified in the periodic main-
tenance and lubrication chart.EBUM0190Front brake pads
Each brake pad is provided with a wear indicator
groove, which allows you to check the brake pad
wear without having to disassemble the brake. To
check the brake pad wear, check the wear indica-
tor groove. If a brake pad has worn to the point that
the wear indicator groove has almost disappeared,
have a Yamaha dealer replace the brake pads as
a set.
1. Rubber cover
2. Throttle lever free play adjusting bolt
3. Locknut
4. Throttle lever free play
4 2 1
3
(a)
(b)
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8-30
8
TIPA rod can be obtained at a Yamaha dealer to make
this adjustment.4. Shift the transmission into neutral.
5. To tighten the drive chain, push the ATV back-
ward. To loosen the drive chain, push the ATV
forward. NOTICE: Improper drive chain
slack will overload the engine as well as
other vital parts of the ATV and can lead to
drive chain slippage or breakage. To pre-vent this from occurring, keep the drive
chain slack within the specified limits.
[ECB00542]
6. Pull the rod out, and then tighten the rear axle
pinch bolts to the specified torque in the order
shown.
7. Check that the clearance between the speed
sensor and the speed sensor rotor is 3–5 mm
(0.12–0.19 in). If the clearance is out of spec-
ification, adjust the speed sensor position as
follows.
1. Rear wheel axle pinch bolt
2. Rod
3. Drive chain tensioner
4. Hole
4 3
2
11
Tightening torque:
Rear axle pinch bolt:
21 Nm (2.1 m·kgf, 15 ft·lbf)
12
5634
78
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8-32
82. Wipe the drive chain dry.
3. Thoroughly lubricate the drive chain with a
special O-ring chain lubricant. NOTICE: Do
not use engine oil or any other lubricants
for the drive chain, as they may contain
substances that could damage the O-
rings.
[ECB00581]
EBU24902
Checking and lubricating the cables The operation and the condition of all control ca-
bles should be checked before each ride, and the
cables and cable ends should be lubricated if nec-essary. If a cable is damaged or does not move
smoothly, have a Yamaha dealer check or replace
it.
WARNING
EWB02581
Inspect cables frequently and replace if dam-
aged. Corrosion can result when the cable
sheaths become damaged, and cables can
also become frayed or kinked, which could
restrict the operation of controls and lead to
an accident or injury.
Always make sure all control cables work
smoothly before you begin riding in cold
weather. If the control cables are frozen or do
not work smoothly, you could be unable to
control the ATV, which could lead to an acci-
dent or collision.
1. O-ring
1 1
Recommended lubricant:
Yamaha Chain and Cable Lube or engine oil
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8-44
8
EBU25752Troubleshooting chart
Check the fuel level in
the fuel tank.1. Fuel
There is enough fuel.
There is no fuel.
Check the compression.
Supply fuel.
The engine does not start.
Check the compression.
Operate the electric starter.2. Compression
There is compression.
There is no compression.
Check the ignition.
Have a Yamaha dealer
check the ATV.
Remove the spark plug
and check the electrodes.3. Ignition
Wipe off with a dry cloth and correct the
spark plug gap, or replace the spark plug.
Have a Yamaha dealer check the ATV.
The engine does not start.
Have a Yamaha dealer
check the ATV.
The engine does not start.
Check the battery.
Operate the electric starter.4. Battery
The engine turns over
quickly.
The engine turns over
slowly.
The battery is good.Check the battery lead connections,
and have a Yamaha dealer charge
the battery if necessary.
DryWet
Open the throttle halfway and operate
the electric starter.
U33B71E0.book Page 44 Wednesday, August 10, 2011 9:01 AM

INDEX
AAccessories and loading ................................................ 6-6
Air filter element, cleaning ............................................ 8-14
Auxiliary light bulb ........................................................ 8-41BBattery .......................................................................... 8-36
Brake and clutch levers, checking and lubricating ....... 8-33
Brake fluid, changing .................................................... 8-25
Brake fluid level, checking ............................................ 8-23
Brake lever ..................................................................... 4-6
Brake lever free play, checking the front ...................... 8-25
Brake light switches ..................................................... 8-27
Brake pads, checking the front and rear ...................... 8-22
Brake pedal .................................................................... 4-6
Brake pedal, checking and lubricating ......................... 8-33
Brake pedal height, checking ....................................... 8-25
Brakes .......................................................................... 8-22
Brakes, front and rear .................................................... 5-3CCables, checking and lubricating ................................. 8-32
Carburetor, adjusting .................................................... 8-20
Chassis fasteners ........................................................... 5-6
Cleaning ......................................................................... 9-1
Clutch lever .................................................................... 4-6
Clutch lever free play, adjusting ................................... 8-28DDrive chain ..................................................................... 5-4
Drive chain, lubricating ................................................. 8-31Drive chain slack .......................................................... 8-29
EEngine break-in .............................................................. 6-4
Engine, cold start ........................................................... 6-1
Engine idling speed ...................................................... 8-20
Engine oil ....................................................................... 5-3
Engine oil and oil filter element .................................... 8-11
Engine, starting a warm ................................................. 6-2
Engine stop switch ......................................................... 4-3FFuel ......................................................................... 4-9, 5-3
Fuel cock ...................................................................... 4-10
Fuel tank cap .................................................................. 4-8
Fuses, replacing ........................................................... 8-38HHandlebar switches ........................................................ 4-3
Hazard switch ................................................................. 4-4
Headlight beam ............................................................ 8-40
Headlight bulb .............................................................. 8-39
High beam indicator light ................................................ 4-2
Horn switch .................................................................... 4-4IIdentification numbers .................................................. 11-1
Indicator lights ................................................................ 4-2
Instruments, lights and switches .................................... 5-6LLabel locations ............................................................... 1-1
Light switch .................................................................... 4-4
U33B71E0.book Page 1 Wednesday, August 10, 2011 9:01 AM