2010 YAMAHA YFM350R check engine

8-17
8
6. Wash the sponge material gently but thor-
oughly in solvent. WARNING! Always use
parts cleaning solvent to clean the sponge
material. Never use low-flash-point sol-
vents or gasoline to clean the sponge ma-
terial because the engine could catch fire
or explode.
[EWB01941]
7. Squeeze the excess solvent out of the sponge
material and let it dry. NOTICE: Do not twist
the sponge material when squeezing it.
[ECB00441]
8. Check the sponge material and replace it if
damaged.
9. Apply Yamaha foam air filter oil or other qual-
ity foam air filter oil to the sponge material.TIPThe sponge material should be wet but not drip-
ping.10. Pull the sponge material over the air filter ele-
ment frame.
11. Apply all-purpose grease to the air filter ele-
ment seat.
12. Insert the air filter element into the air filter
case, and then install the air filter case cover
by hooking the holders onto the air filter case.
1. Air filter element retaining plate
2. Air filter element frame
3. Sponge material
4. Air filter element seatU1BS60E0.book Page 17 Thursday, April 16, 2009 4:11 PM

8-18
8 NOTICE: Make sure that the air filter ele-
ment is properly seated in the air filter
case. Never operate the engine with the air
filter element removed. This will allow un-
filtered air to enter the engine, causing rap-
id engine wear and possible engine
damage. Additionally, operation without
the air filter element will affect carburetor
jetting with subsequent poor performance
and possible engine overheating.
[ECB00461]
13. Install the seat.TIPThe air filter element should be cleaned every 20–
40 hours. It should be cleaned and lubricated more
often if the ATV is operated in extremely dusty ar-
eas. Each time the air filter element maintenance
is performed, check the air inlet of the air filter case
for obstructions. Check the air filter case rubber
joint to the carburetor fittings and the rubber joint
manifold fittings for an air-tight seal. Tighten all fit-
tings securely to avoid the possibility of unfiltered
air entering the engine.
EBU27701Cleaning the spark arrester Select a well-ventilated area free of combustible
materials and make sure the exhaust and muffler
are cool.
1. Remove the bolt.
2. Remove the tailpipe by pulling it out of the
muffler.
3. Tap the tailpipe lightly, and then use a wire
brush to remove any carbon deposits from the
spark arrester portion of the tailpipe and inside
of the tailpipe housing.1. Bolt
U1BS60E0.book Page 18 Thursday, April 16, 2009 4:11 PM

8-20
8
WARNING
EWB02380Never run the engine in an enclosed area when
purging the spark arrester, otherwise it could
cause injury to the eyes, burns, carbon monox-
ide poisoning, possibly leading to death, and
start a fire.
Always let the exhaust system cool prior to
touching exhaust components.
Always wear eye protection, and make sure
no one is behind the ATV.
Make sure there are no combustible materi-
als in the area.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 adjustmentdescribed 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.
U1BS60E0.book Page 20 Thursday, April 16, 2009 4:11 PM

8-21
82. 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).
TIPIf the specified idling speed cannot be obtained as
described above, have a Yamaha dealer make the
adjustment.EBU24045Adjusting the throttle cable free play The throttle cable free play should be checked
and, if necessary, adjusted at the intervals speci-
fied in the periodic maintenance and lubrication
chart.
The throttle cable free play should measure 2.0–
4.0 mm (0.08–0.16 in) at the throttle lever. Period-
ically check the throttle cable free play and, if nec-
essary, adjust it as follows.TIPThe engine idling speed must be checked, and ad-
justed if necessary, before adjusting the throttle ca-
ble free play.1. Slide the rubber cover back.
2. Loosen the locknut.
3. To increase the throttle cable free play, turn
the throttle cable free play adjusting bolt in di-
rection (a). To decrease the throttle cable free
play, turn the adjusting bolt in direction (b).
1. Throttle stop screwEngine idling speed:
1450–1550 r/min
U1BS60E0.book Page 21 Thursday, April 16, 2009 4:11 PM

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.EBU28790Front brake pads
Each brake pad is provided with two wear indicator
grooves, which allow you to check the brake pad
wear without having to disassemble the brake. To
check the brake pad wear, check the wear indica-
tor grooves. If a brake pad has worn to the point
that a wear indicator groove almost appears, have
a Yamaha dealer replace the brake pads as a set.
1. Rubber cover
2. Throttle cable free play adjusting bolt
3. Locknut
4. Throttle cable free play
3
12
4
U1BS60E0.book Page 22 Thursday, April 16, 2009 4:11 PM

8-32
8 2. 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]
EBU24901
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.EBU24922Checking and lubricating the brake and
clutch levers The operation of the brake and clutch levers
should be checked before each ride, and the lever
pivots should be lubricated if necessary.
1. O-ring
Recommended lubricant:
Engine oil
U1BS60E0.book Page 32 Thursday, April 16, 2009 4:11 PM

8-46
8
EBU25751Troubleshooting 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 charge the battery if necessary.
DryWet
Open the throttle halfway and operate
the electric starter.
U1BS60E0.book Page 46 Thursday, April 16, 2009 4:11 PM

9-2
9
EBU25933Storage Short-term
Always store your ATV in a cool, dry place and, if
necessary, protect it against dust with a porous
cover. NOTICE: Storing the ATV in a poorly ven-
tilated room or covering it with a tarp while it is
still wet, will allow water and humidity to seep
in and cause rust. To prevent corrosion, avoid
damp cellars, stables (because of the presence
of ammonia) and areas where strong chemi-
cals are stored.
[ECB00721]
Long-term
Before storing your ATV for several months:
1. Follow all the instructions in the “Cleaning”
section of this chapter.
2. Turn the fuel cock lever to “OFF”.
3. Drain the carburetor float chamber by loosen-
ing the drain bolt; this will prevent fuel deposits
from building up. Pour the drained fuel into the
fuel tank.
4. Fill up the fuel tank and add fuel stabilizer (if
available) to prevent the fuel from deteriorat-
ing.5. Perform the following steps to protect the cyl-
inder, 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 sparking 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.
6. Lubricate all control cables and the pivoting
points of all levers and pedals.
7. Check and, if necessary, correct the tire air
pressure, and then block up the ATV so that
all of its wheels are off the ground. Alternative- Specified amount:
7.5 ml of stabilizer to each liter of fuel (or 1 oz
of stabilizer to each gallon of fuel)U1BS60E0.book Page 2 Thursday, April 16, 2009 4:11 PM