2003 YAMAHA GRIZZLY 660 engine

8-61 1. Coolant drain bolt
1. Boulon de vidange du liquide de refroidissement
1. Perno de drenaje del refrigerante
1. Trough
1. Feuille de papier repliée en forme de conduit
1. Pasante
EBU00977
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 panels E and F. (See pages 8-29–
8-31 for removal and installation procedures.)
3. Place a container under the engine, and then
remove the coolant drain bolt. (Use a trough
or a similar object as shown to prevent cool-
ant from spilling on the footrest.)
4. Remove the front carrier and panel C. (See
pages 8-23 and 8-27 for removal and installa-
tion procedures.)
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8-65
10. Install the coolant reservoir hose.
11. Pour the recommended coolant into the radi-
ator until it is full.CAUTION:_ Hard water or salt water is harmful to the en-
gine. You may use soft water if you can’t get
distilled water. _
Recommended antifreeze:
High quality ethylene glycol antifreeze
containing corrosion inhibitors for
aluminum engines.
Antifreeze and water mixing ratio:
1:1
Total amount:
1.8 L
Coolant reservoir capacity
(up to the maximum level mark):
0.3 L
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8-67
12. Install the radiator 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. Fill the coolant reservoir with coolant up to
the maximum level.
15. Install the coolant reservoir cap and check for
coolant leakage.NOTE:_ If any leakage is found, ask a Yamaha dealer to in-
spect the cooling system. _16. Install the panels and the front carrier.
U5KM61.book Page 67 Friday, July 26, 2002 11:13 AM

8-71 1. Spark plug cap
1. Capuchon de bougie
1. Tapa de bujía
1. Spark plug wrench
1. Clé à bougie
1. Llave de bujía
EBU00864
Spark plug inspection
Removal
1. Remove panel A. (See page 8-17 for panel
removal and installation procedures.)
2. Remove the spark plug cap.
3. 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.
U5KM61.book Page 71 Friday, July 26, 2002 11:13 AM

8-79 1. Air filter element
1.Élément de filtre à air
1. Elemento del filtro de aire
1. Air filter element frame
1. Armature d’élément de filtre à air
1. Bastidor del elemento del filtro de aire
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. _6. 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. _7. Inspect the air filter element and replace it if
damaged.
8. Apply foam air filter oil to the air filter element.
If foam air filter oil is not available, engine oil
may be used.NOTE:_ The air filter element should be wet but not drip-
ping. _
U5KM61.book Page 79 Friday, July 26, 2002 11:13 AM

8-81 1. Breather hose
1. Reniflard
1. Manguera del respiradero
9. Pull the air filter element over its frame.
10. Install the air filter element.
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. _
U5KM61.book Page 81 Friday, July 26, 2002 11:13 AM

8-83 1. V-belt cooling duct check hose (Left side)
1. Flexible de contrôle du conduit de refroidissement de la courroie
trapézoïdale (côté gauche)
1. Manguera de comprobación del conducto de enfriamiento de
la correa trapezoidal (Lado izquierdo)
1. V-belt case drain plug
1. Boulon de vidange du carter de la courroie
1. Tapón de drenaje de la caja de la correa trapezoidal
EBU00874
V-belt cooling duct check hose
If dust or water collects in the V-belt cooling duct
check hose, remove the hose and clean it.
V-belt case drain plug
After riding in water deep enough to allow it to en-
ter the V-belt case, remove this plug to drain the
water from the case.NOTE:_ If water drains from the V-belt case after removing
the plug, have a Yamaha dealer inspect the ATV
as the water may affect other engine parts. _
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8-85
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.
U5KM61.book Page 85 Friday, July 26, 2002 11:13 AM