2004 YAMAHA YFM350R engine

8-19 1. Engine oil filter cover 2. Bolt (× 3)
3. Engine oil filter element 4. O-ring
1. Couvercle du filtre à huile de moteur 2. Boulon (× 3)
3.Élément du filtre à huile de moteur
4. Joint torique
1. Tapa del filtro de aceite de motor 2. Perno (× 3)
3. Elemento del filtro de aceite de motor
4. Junta tórica
NOTE:_ Skip steps 5–9 if the oil filter element is not being
cleaned. _5. Remove the oil filter cover by removing the
bolts, and then remove the oil filter element.
6. Clean the oil strainer and oil filter element
with solvent.
7. Check the O-ring for damage and replace it if
necessary.
8. Install the oil filter element and O-ring.NOTE:_ Make sure the O-ring is seated properly. _9. Install the oil filter cover by installing the bolts,
and then tighten them to the specified torque.
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8-21
10. Install the oil strainer, compression spring,
O-ring and engine oil drain bolt. Tighten the
engine oil drain bolt to the specified torque.CAUTION:_ Before installing the engine oil drain bolt, be
sure to install the O-ring, compression spring
and oil strainer. _11. Add the specified amount of the recommend-
ed engine oil, and then install and tighten the
engine oil filler cap. Tightening torque:
Oil filter cover bolt:
32 Nm (3.2 m·kgf)
Tightening torque:
Engine oil drain bolt:
10 Nm (1.0 m·kgf)
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8-23
CAUTION:_

In order to prevent clutch slippage (since
the engine oil also lubricates the clutch),
do not mix any chemical additives. Do not
use oils with a diesel specification of “CD”
or oils of a higher quality than specified. In
addition, do not use oils labeled “ENERGY
CONSERVING II” or higher.


Make sure that no foreign material enters
the crankcase.
_
Recommended oil:
See page 10-2.
Oil quantity:
Without oil filter element replacement:
2.5 L
With oil filter element replacement:
2.6 L
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8-25
12. Start the engine, and then let it idle for seve-
ral 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, and then check the oil
level and correct it if necessary.
U5YT60.book Page 25 Friday, December 12, 2003 1:55 PM

8-27 1. Spark plug cap
1. Capuchon de bougie
1. Tapa de bujía
1. Spark plug wrench
1. Clé à bougie
1. Llave de bujía
EBU14550
Spark plug inspection
Removal
1. Remove the spark plug cap.
2. Use the spark plug wrench in the owner’s tool
kit to remove the spark plug as shown.
Inspection
The spark plug is an important engine component
and is easy to inspect. The condition of the spark
plug can indicate the condition of the engine.
The ideal color on the white insulator around the
center electrode is a medium-to-light tan color for
an ATV that is being ridden normally.
Do not attempt to diagnose such problems your-
self.
Instead, take the ATV to a Yamaha dealer. You
should periodically remove and inspect the spark
plug because heat and deposits will cause the
spark plug to slowly break down and erode. If elec-
trode erosion becomes excessive, or if carbon and
other deposits are excessive, you should replace
the spark plug with the specified plug.
Specified spark plug:
DR8EA (NGK)
U5YT60.book Page 27 Friday, December 12, 2003 1:55 PM

8-33 1. Air filter element assembly
1.Élément de filtre à air
1. Conjunto del elemento del filtro de aire
1. Unlock.
1. Déverrouiller
1. Desbloquear
3. Remove the air filter element assembly, and
then remove the air filter element from its
frame.
4. Wash the element gently but thoroughly in
solvent.
WARNING
_ Always use parts cleaning solvent to clean the
air filter element. Never use low flash point sol-
vents or gasoline to clean the air filter element
because the engine could catch fire or ex-
plode. _5. Squeeze the excess solvent out of the air fil-
ter element and let it dry.CAUTION:_ Do not twist the air filter element when squeez-
ing it. _
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8-37
NOTE:_ The air filter element should be cleaned every 20–
40 hours. It should be cleaned and lubricated more
often if the machine is operated in extremely dusty
areas. Each time the air filter element mainte-
nance is performed, check the air inlet to the filter
case for obstructions. Check the air filter case rub-
ber joint to the carburetor and manifold fittings for
an airtight seal. Tighten all fittings securely to
avoid the possibility of unfiltered air entering the
engine. _CAUTION:_ Never operate the engine with the air filter ele-
ment removed. This will allow unfiltered air to
enter, causing rapid engine wear and possible
engine damage. Additionally, operation with-
out the air filter element will affect carburetor
jetting with subsequent poor performance and
possible engine overheating. _
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8-39
EBU00296
Carburetor adjustment
The carburetor is a vital part of the engine and re-
quires very sophisticated adjustment. Most adjust-
ing should be left to a Yamaha dealer who has the
professional knowledge and experience to do so.
However, the idling speed may be performed by
the owner as a part of the usual maintenance rou-
tine.CAUTION:
The carburetor was set at the Yamaha factory
after many tests. If the settings are disturbed
by someone without sufficient technical
knowledge, poor engine performance and
damage may result.
U5YT60.book Page 39 Friday, December 12, 2003 1:55 PM