engine YAMAHA YFM660R 2005 Workshop Manual

8-31
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 engine oil:
See page 10-2.
Oil quantity:
Without oil filter cartridge replacement:
1.9 L
With oil filter cartridge replacement:
1.95 L
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8-33
15. 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.
16. Turn the engine off, and then check the oil
level and correct it if necessary.
17. Install the engine guard by installing the bolts.
U5LP64.book Page 33 Thursday, April 1, 2004 4:53 PM

8-35 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
EBU10151
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.NOTE:_ The coolant should be between the minimum and
maximum level marks. _2. If the coolant is at or below the minimum level
mark, remove the coolant reservoir cap, and
then add coolant or distilled water 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. _
Coolant reservoir capacity
(up to the maximum level mark):
0.29 L
U5LP64.book Page 35 Thursday, April 1, 2004 4:53 PM

8-39 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
EBU10241
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 8-17 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.
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8-43
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
(up to the maximum level mark):
0.29 L
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8-45
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.
U5LP64.book Page 45 Thursday, April 1, 2004 4:53 PM

8-47 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.
U5LP64.book Page 47 Thursday, April 1, 2004 4:53 PM

8-53 1. Check hose
1. Flexible de contrôle
1. Manguito de comprobación
1. Air filter case cover 2. Holder (× 6)
1. Couvercle du boîtier de filtre à air 2. Support (× 6)
1. Tapa de la caja del filtro 2. Soporte (× 6)
EBU12121
Air filter element cleaningNOTE:_ 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. Remove the seat. (See page 4-33 for seat re-
moval and installation procedures.)
2. Remove the air filter case cover by unhook-
ing the holders.
3. Remove the air filter element.
4. Remove the air filter element from its frame.
5. Wash the air filter element gently but thor-
oughly 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. _
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8-57 1. Hose
1. Flexible
1. Manguera
11. Install the air filter case cover and be sure to
connect the hose.
12. Install the seat.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 air filter element maintenance is
performed, check the air inlet to the air filter case
for obstructions. Check the air filter element rubber
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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8-59
EBU15160
Carburetor adjustment
The carburetors are vital parts of the engine and
require very sophisticated adjustment. Most ad-
justing 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
routine.CAUTION:_ The carburetors were set at the Yamaha facto-
ry after many tests. If the settings are dis-
turbed by someone without sufficient
technical knowledge, poor engine perfor-
mance and damage may result. _
U5LP64.book Page 59 Thursday, April 1, 2004 4:53 PM