2002 YAMAHA YFM660R engine

8-25 1. Oil filter cartridge
2. Oil filter wrench
1. Cartouche du filtre à huile
2. Clé pour filtre à huile
1. Cartucho del filtro de aceite
2. Llave para filtros de aceite
1. O-ring
1. Joint torique
1. Junta tórica
7. Remove the oil filter cartridge with an oil filter
wrench.NOTE:_ An oil filter wrench is available at a nearby
Yamaha dealer. _8. Apply a thin coat of engine oil to the O-ring of
the new oil filter cartridge.NOTE:_ Make sure that the O-ring is properly seated. _9. Install a new oil filter cartridge and tighten it to
the specified torque with a torque wrench.
10. Install the crankcase engine oil drain bolt and
the engine oil tank drain bolt, then tighten
them to the specified torques. Tightening torque:
Oil filter cartridge:
17 Nm (1.7 m·kgf)
Tightening torques:
Crankcase engine oil drain bolt:
30 Nm (3.0 m·kgf)
Engine oil tank drain bolt:
25 Nm (2.5 m·kgf)
U5LP61.book Page 25 Monday, August 27, 2001 3:49 PM

8-27
11. Add sufficient oil of the recommended type to
raise it to the correct level, and then install
and tighten the oil tank filler cap.CAUTION:_

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


Make sure that no foreign material enters
the crankcase.
_
Recommended engine oil:
See page 10-2.
U5LP61.book Page 27 Monday, August 27, 2001 3:49 PM

8-29
12. Start the engine, and then let it idle for sever-
al 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.
U5LP61.book Page 29 Monday, August 27, 2001 3:49 PM

8-31 1. Coolant reservoir cap
2. Maximum level mark
3. Minimum level mark
1. Bouchon du vase d’expansion
2. Repère de niveau maximum
3. Repère de niveau minimum
1. Tapa del depósito de líquido refrigerante
2. Marca de nivel máximo
3. Marca de nivel mínimo
EBU01015
Cooling system
1. Check the coolant level in the coolant reser-
voir when the engine is cold as the coolant
level will vary with engine temperature. The
coolant level should be between the maxi-
mum and minimum marks.
2. If the level is low, remove the coolant reser-
voir cap, and then add coolant or distilled wa-
ter to raise it to the specified level.CAUTION:_ Hard water or salt water is harmful to the en-
gine. You may use soft water if you can’t get
distilled water. _NOTE:_

If water is added, have a Yamaha dealer
check the antifreeze content of the coolant as
soon as possible.


The radiator fan operation is completely auto-
matic. It is switched on or off according to the
coolant temperature in the radiator.
_If your ATV overheats, see page 8-122 for details.Coolant reservoir capacity:
0.29 L
U5LP61.book Page 31 Monday, August 27, 2001 3:49 PM

8-33 1. Coolant drain bolt
1. Boulon de vidange du liquide de refroidissement
1. Perno de drenaje de refrigerante
1. Radiator cap
1. Bouchon de radiateur
1. Tapa del radiador
EBU01024
Changing the coolant
WARNING
_ Wait for the engine and radiator to cool before
removing the radiator cap. You could be
burned by hot fluid and steam blown out under
pressure. Always put a thick rag over the cap
when opening. Allow any remaining pressure
to escape before completely removing the cap. _1. Place the ATV on a level surface.
2. Remove panel A. (See page 8-15 for panel
removal and installation procedures.)
3. Place a container under the engine, and then
remove the coolant drain bolt.
4. Remove the radiator cap.
U5LP61.book Page 33 Monday, August 27, 2001 3:49 PM

8-37
Recommended antifreeze:
High quality ethylene glycol antifreeze
containing corrosion inhibitors for
aluminum engines.
Antifreeze and water mixing ratio:
1:1
Total amount:
1.3 L
Coolant reservoir capacity:
0.29 L
U5LP61.book Page 37 Monday, August 27, 2001 3:49 PM

8-39
CAUTION:_ Hard water or salt water is harmful to the en-
gine. You may use soft water if you cannot get
distilled water. _12. Install the radiator cap and the coolant reser-
voir cap.
13. Start the engine and let it idle for several min-
utes. Stop the engine, and then check the
coolant level in the radiator. If it is low, add
more coolant until it reaches the top of the ra-
diator.
14. Check the coolant level in the reservoir. If it is
low, add coolant to the maximum level mark.
15. Start the engine and then check for coolant
leakage.NOTE:_ If any leakage is found, have a Yamaha dealer
check the cooling system. _16. Install the panel.
U5LP61.book Page 39 Monday, August 27, 2001 3:49 PM

8-41 1. Spark plug cap
1. Capuchon de bougie
1. Tapa de bujía
EBU00680
Spark plug inspection
Removal
1. Remove the spark plug cap.
2. Use the spark plug wrench in the tool kit to re-
move 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 a
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.
U5LP61.book Page 41 Monday, August 27, 2001 3:49 PM