YAMAHA YFM250R 2009 Manual Online

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EBU23211
Checking 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 thespark 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).TIP

If 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.
1. Spark plug cap
1

1. Spark plug wrench
1

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2. Check the spark plug for electrode erosion
and excessive carbon or other deposits, and
replace it if necessary.
To install the spark plug
1. Measure the spark plug gap with a wire thick-
ness gauge and, if necessary, adjust the gap
to specification.2. Clean the surface of the spark plug gasket
and its mating surface, and then wipe off any
grime from the spark plug threads.
3. Install the spark plug with the spark plug
wrench, and then tighten it to the specified
torque.TIP

If 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.
4. Install the spark plug cap.
EBU28953
Engine 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 must be replaced at the inter-
vals specified in the periodic maintenance and lu-
brication chart. Specified spark plug:
NGK/DR7EA
Spark plug gap:
0.6–0.7 mm (0.024–0.028 in)
1. Spark plug gap
Tightening torque:
Spark plug:
18 Nm (1.8 m·kgf, 13 ft·lbf)

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To check the engine oil level
1. Place the ATV on a level surface.
2. Check the engine oil level on a cold engine.
TIP

If 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 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.
TIP

The engine oil should be between the minimum
and maximum level marks.
5. If the engine oil is at or below the minimum
level mark, add sufficient oil of the recom-
mended type to raise it to the correct level.
6. Insert the dipstick into the oil filler hole, and
then tighten the engine oil filler cap.
1. Engine oil filler cap
2. Dipstick
3. Maximum level mark
4. Minimum level mark
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To change the engine oil (with or without oil
filter element replacement)
1. Start the engine, warm it up for several min-
utes, and then turn it off.
2. Place an oil pan under the engine to collect
the used oil.
3. Remove the engine oil filler cap, and then re-
move the engine oil drain bolt to drain the oil
from the crankcase.
TIP

Skip steps 4–7 if the oil filter element is not being
replaced.4. Remove the oil filter element cover by remov-
ing the bolts, and then remove the oil filter el-
ement.
5. Check the O-rings for damage and replace
them if necessary.
1. Engine oil drain bolt
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1. Oil filter element cover
2. Bolt
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6. Install a new oil filter element.
TIP

Make sure that the O-rings are properly seated.
7. Install the oil filter element cover by installing
the bolts, and then tighten them to the speci-
fied torque.8. Install the engine oil drain bolt and tighten it to
the specified torque.
9. Refill with the specified amount of the recom-
mended engine oil, and then install and tight-
en the engine oil filler cap.TIP

Be sure to wipe off spilled oil on any parts after the
engine and exhaust system have cooled down.NOTICE

ECB00300

In order to prevent clutch slippage (since the
engine oil also lubricates the clutch), do not
mix any chemical additives. Do not use oils
1. Oil filter element
2. O-ring
Tightening torque:
Oil filter element cover bolt:
10 Nm (1.0 m·kgf, 7.2 ft·lbf)
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2
2

Tightening torque:
Engine oil drain bolt:
20 Nm (2.0 m·kgf, 14.5 ft·lbf)
Recommended oil:
See page 10-1.
Oil quantity:
Without oil filter element replacement:
1.25 L (1.32 US qt, 1.10 Imp.qt)
With oil filter element replacement:
1.35 L (1.43 US qt, 1.19 Imp.qt)

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with a diesel specification of “CD” or oils of
a higher quality than specified. In addition,
do not use oils labeled “ENERGY CONSERV-
ING II” or higher.

Make sure that no foreign material enters the
crankcase.
10. 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.
11. Turn the engine off, wait at least ten minutes,
and then check the oil level and correct it if
necessary.
EBU23703
Cleaning the air filter element
The air filter element should be cleaned at the in-
tervals specified in the periodic maintenance and
lubrication chart. Clean the air filter element more
frequently if you are riding in unusually wet or dusty
areas.
TIP

There 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. “CD” specification
2. “ENERGY CONSERVING II”
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1. Air filter case check hose
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1. Place the ATV on a level surface.
2. Remove the seat. (See page 4-10.)
3. Remove the air filter case cover by unhooking
the holders.
4. Loosen the wing bolt.
5. Remove the air filter element together with the
wing bolt and washer.6. Remove the wing bolt and washer from the air
filter element.
7. Remove the sponge material from the air filter
element frame.
1. Air filter case cover
2. Air filter case cover holder
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1. Wing bolt
2. Air filter element
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8. Wash the sponge material gently but thor-
oughly in solvent.
WARNING

EWB01940
Always use parts cleaning solvent to clean the
sponge material. Never use low-flash-point
solvents or gasoline to clean the sponge mate-
rial because the engine could catch fire or ex-
plode.
9. Squeeze the excess solvent out of the sponge
material and let it dry.NOTICE

ECB00440
Do not twist the sponge material when squeez-
ing it.
10. Check the sponge material and replace it if
damaged.
11. Apply a quality foam air filter oil to the sponge
material.
TIP

The sponge material should be wet but not drip-
ping.
12. Pull the sponge material over the air filter ele-
ment frame.
1. Sponge material
2. Air filter element frame
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2

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13. Install the washer onto the air filter element
frame, and then insert the wing bolt into the
hole in the air filter element frame.
NOTICE

ECB00451
Be sure to install the washer with the bent edge
facing outward as shown.
14. Insert the air filter element into the air filter
case, and then tighten the wing bolt.
15. Install the air filter case cover by hooking the
holders onto the air filter case.
16. Install the seat.
TIP

The 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.
NOTICE

ECB00460

Make sure that the air filter element is prop-
erly seated in the air filter case.

Never operate the engine with the air filter el-
ement removed. This will allow unfiltered air
to enter the engine, causing rapid engine
wear and possible engine damage. Addition-
ally, operation without the air filter element
will affect carburetor jetting with subsequent
poor performance and possible engine over-
heating.
1. Washer
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EBU28900
Cleaning the spark arrester
Be sure the exhaust pipe and muffler are cool be-
fore cleaning the spark arrester.
1. Remove the bolts.
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.4. Make sure the gasket is properly positioned,
then insert the tailpipe into the muffler and
align the bolt holes.
1. Bolt
2. Tailpipe
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1. Tailpipe
2. Spark arrester
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