2010 YAMAHA YFM350R check engine

7-8
7WARNING! Operating this ATV with improper
modifications may cause changes in handling
which in some situations could lead to an acci-
dent.
[EWB01491]
Exhaust system
WARNING
EWB01501
Dry grass or brush or other combustible ma-
terial accumulated around the engine area
could catch fire. Do not operate, idle, or park
the ATV in dry grass or other dry ground cov-
er. Keep the engine area free of dry grass,
brush, or other combustible material.
Someone touching the exhaust system dur-
ing or after operation could be burned. Do
not touch the hot exhaust system. Do not
park the ATV in a place where others might
be likely to touch it.The muffler and other engine parts become ex-
tremely hot during operation and remain hot after
the engine has stopped. To reduce the risk of fire
during operation or after leaving the ATV, do not let
brush, grass and other materials collect under the
vehicle, near the muffler or exhaust pipe, or next to
other hot parts. Check under the vehicle after op-erating in areas where combustible materials may
have collected. Do not idle or park the vehicle in
long dry grass or other dry ground cover.
To prevent burns, avoid touching the exhaust sys-
tem. Park the ATV in a place where pedestrians or
children are not likely to touch it.U1BS60E0.book Page 8 Thursday, April 16, 2009 4:11 PM

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8
EBU21743Periodic maintenance chart for the emission control system TIP
For ATVs not equipped with an odometer or an hour meter, follow the month maintenance intervals.
For ATVs equipped with an odometer or an hour meter, follow the km (mi) or hours maintenance inter-
vals. However, keep in mind that if the ATV isn’t used for a long period of time, the month maintenance
intervals should be followed.
Items marked with an asterisk should be performed by a Yamaha dealer as they require special tools,
data and technical skills.NO. ITEMCHECK OR MAINTENANCE
JOBINITIAL EVERY
Whichev-
er comes
firstmonth136612
km
(mi)320
(200)1300
(800)2500
(1600)2500
(1600)5000
(3200)
hours 20 80 160 160 320
1*Fuel lineCheck fuel hoses for cracks or other damage, and
replace if necessary.√√√
2 Spark plugCheck condition and clean, regap, or replace if
necessary.√√√√√
3*ValvesCheck valve clearance and adjust if necessary.√ √√√
4*CarburetorCheck starter (choke) operation and correct if nec-
essary.
Check engine idling speed and adjust if neces-
sary.√√√√
5*Crankcase breather
systemCheck breather hose for cracks or other damage,
and replace if necessary.√√√
U1BS60E0.book Page 3 Thursday, April 16, 2009 4:11 PM

8-7
8
15*Shock absorber as-
sembliesCheck operation and correct if necessary.
Check for oil leakage and replace if necessary.√√√
16*Rear suspension re-
lay arm and con-
necting arm
pivoting pointsCheck operation and correct if necessary.
Lubricate with lithium-soap-based grease.√√√√
17*Steering shaftLubricate with lithium-soap-based grease.√√√
18*Steering systemCheck operation and repair or replace if damaged.
Check toe-in and adjust if necessary.√√√√√
19 Engine oilChange.
Check ATV for oil leakage, and correct if neces-
sary.√ √√√
20Engine oil filter ele-
mentClean or replace if necessary.√√√
21 Engine oil strainerClean.√√√
22*Moving parts and
cablesLubricate.√√√√
23*Throttle lever hous-
ing and cableCheck operation and correct if necessary.
Check throttle cable free play and adjust if neces-
sary.
Lubricate throttle lever housing and cable.√√√√√
24*Front and rear brake
switchesCheck operation and correct if necessary.√√√√√
25*Lights and switchesCheck operation and correct if necessary.
Adjust headlight beams.√√√√√ NO. ITEMCHECK OR MAINTENANCE
JOBINITIAL EVERY
Whichev-
er comes
firstmonth136612
km
(mi)320
(200)1300
(800)2500
(1600)2500
(1600)5000
(3200)
hours 20 80 160 160 320U1BS60E0.book Page 7 Thursday, April 16, 2009 4:11 PM

8-9
8
EBU23212Checking the spark plug The spark plug is an important engine component,
which is easy to check. Since heat and deposits
will cause any spark plug to slowly erode, the spark
plug should be removed and checked in accor-
dance with the periodic maintenance and lubrica-
tion chart. In addition, the condition of the spark
plug can reveal the condition of the engine.
To remove the spark plug
1. Remove the spark plug cap.2. Remove the spark plug as shown, with the
spark plug wrench included in the owner’s tool
kit.
To check the spark plug
1. Check that the porcelain insulator around the
center electrode of the spark plug is a medi-
um-to-light tan (the ideal color when the ATV
is ridden normally).1. Spark plug cap
1. Spark plug wrench
U1BS60E0.book Page 9 Thursday, April 16, 2009 4:11 PM

8-10
8
TIPIf the spark plug shows a distinctly different color,
the engine could be operating improperly. Do not
attempt to diagnose such problems yourself. In-
stead, have a Yamaha dealer check the ATV.2. Check the spark plug for electrode erosion
and excessive carbon or other deposits, and
replace it if necessary.
3. Measure the spark plug gap with a wire thick-
ness gauge and, if necessary, adjust the gap
to specification.
To install the spark plug
1. Clean the surface of the spark plug gasket
and its mating surface, and then wipe off any
grime from the spark plug threads.
2. Install the spark plug with the spark plug
wrench, and then tighten it to the specified
torque. Specified spark plug:
NGK/DR8EA
1. Spark plug gapSpark plug gap:
0.6–0.7 mm (0.024–0.028 in)
U1BS60E0.book Page 10 Thursday, April 16, 2009 4:11 PM

8-11
8
TIPIf a torque wrench is not available when installing
a spark plug, a good estimate of the correct torque
is 1/4–1/2 turn past finger tight. However, the spark
plug should be tightened to the specified torque as
soon as possible.3. Install the spark plug cap.EBU2327CEngine oil and oil filter element The engine oil level should be checked before
each ride. In addition, the oil must be changed and
the oil filter element cleaned at the intervals speci-
fied in the periodic maintenance and lubrication
chart.
To check the engine oil level
1. Place the ATV on a level surface.
2. Check the engine oil level on a cold engine.
TIPIf the engine was started before checking the oil
level, be sure to warm up the engine sufficiently,
and then wait at least ten minutes until the oil set-
tles for an accurate reading.3. Remove the engine oil filler cap, and then
wipe the engine oil dipstick off with a clean
rag.
4. Insert the dipstick into the filler hole (without
screwing it in), and then remove it again to
check the oil level.TIPThe engine oil should be between the minimum
and maximum level marks.
Tightening torque:
Spark plug:
17.5 Nm (1.75 m·kgf, 12.7 ft·lbf)
U1BS60E0.book Page 11 Thursday, April 16, 2009 4:11 PM

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8
TIPSkip steps 5–9 if the oil filter element is not being
cleaned.5. Remove the oil filter element cover by remov-
ing the bolts, and then remove the oil filter el-
ement.6. Clean the oil strainer and oil filter element with
solvent.
7. Check the O-rings for damage and replace
them if necessary.
8. Install the oil filter element and O-ring.
TIPMake sure that the O-ring is properly seated.9. Install the oil filter element cover by installing
the bolts, and then tighten them to the speci-
fied torque.
1. Engine oil drain bolt
2. O-ring
3. Compression spring
4. Oil strainer
1. Oil filter element cover
2. Bolt
3. Oil filter element
4. O-ring
U1BS60E0.book Page 13 Thursday, April 16, 2009 4:11 PM

8-15
812. Start the engine, and then let it idle for several
minutes while checking it for oil leakage. If oil
is leaking, immediately turn the engine off and
check for the cause.
13. Turn the engine off, wait at least ten minutes,
and then check the oil level and correct it if
necessary.
EBU23743Cleaning the air filter element The air filter element should be cleaned at the in-
tervals specified in the periodic maintenance and
lubrication chart. Clean or, if necessary, replace
the air filter element more frequently if you are
riding in unusually wet or dusty areas.TIPThere is a check hose at the bottom of the air filter
case. If dust or water collects in this hose, empty
the hose and clean the air filter element and air fil-
ter case.
1. Place the ATV on a level surface.
2. Remove the seat. (See page 4-12.)
3. Remove the air filter case cover by unhooking
the holders.1. Air filter case check hose
U1BS60E0.book Page 15 Thursday, April 16, 2009 4:11 PM