engine YAMAHA GRIZZLY 660 2003 Workshop Manual

8-65
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.
U5KM60.book Page 65 Thursday, June 21, 2001 2:40 PM

8-69 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.
U5KM60.book Page 69 Thursday, June 21, 2001 2:40 PM

8-77 1. Air filter element
1.Élément de filtre à air
1. Elemento del filtro de aire
1. Air filter guide
1. Guide de filtre à air
1. Filtro de aire guía
3. Remove the air filter element and remove it
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 filter
element and let it dry.CAUTION:_ Do not twist the filter element when squeezing
it. _6. Inspect the element and replace it if dam-
aged.
7. Apply foam air filter oil to the element. If foam
air filter oil is not available, motor oil may be
used.NOTE:_ The element should be wet but not dripping. _
U5KM60.book Page 77 Thursday, June 21, 2001 2:40 PM

8-79 1. Breather hose
1. Reniflard
1. Manguera del respiradero
8. Pull the element over its frame.
9. Install the element assembly.
10. Install the air filter case cover and be sure to
connect the hose.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 filter element maintenance is
performed, check the air inlet to the filter case for
obstructions. Check the air cleaner rubber joint to
the carburetor and manifold fittings for an airtight
seal. Tighten all fittings securely to avoid the pos-
sibility 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 filter element will affect carburetor jet-
ting with subsequent poor performance and
possible engine overheating. _
U5KM60.book Page 79 Thursday, June 21, 2001 2:40 PM

8-81 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 a lot of water drains from the V-belt case after re-
moving the plug, have a Yamaha dealer inspect
the ATV as the water may affect other engine
parts. _
U5KM60.book Page 81 Thursday, June 21, 2001 2:40 PM

8-83
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.
U5KM60.book Page 83 Thursday, June 21, 2001 2:40 PM

8-85 1. Throttle stop screw
1. Vis d’arrêt de l’accélérateur
1. Tornillo de tope del acelerador
EBU00657
Idle speed adjustmentNOTE:A diagnostic tachometer must be used for this pro-
cedure.1. Start the engine and warm it up for a few min-
utes at approximately 1,000 to 2,000 r/min.
Occasionally rev the engine to 4,000 to
5,000 r/min. The engine is warm when it
quickly responds to the throttle.
2. Remove panel D. (See pages 8-17 ~ 8-19 for
removal and installation procedures.)
3. Connect the tachometer and set the idle to
the specified idling speed by adjusting the
throttle stop screw. Turn the screw in to in-
crease engine speed, and out to decrease
engine speed.
4. Install the panel.Specified idle speed:
1,450 ~ 1,550 r/min
U5KM60.book Page 85 Thursday, June 21, 2001 2:40 PM

8-87
EBU00303
Valve clearance adjustment
The correct valve clearance changes with use, re-
sulting in improper fuel/air supply or engine noise.
To prevent this, the valve clearance must be ad-
justed regularly. This adjustment however, should
be left to a professional Yamaha service techni-
cian.
U5KM60.book Page 87 Thursday, June 21, 2001 2:40 PM

8-89 1. Locknut 2. Adjusting bolt a. Free play
1. Contre-écrou 2. Bouchon de réglage a. Jeu
1. Contratuerca 2. Perno de ajuste a. Juego libre
EBU00307
Throttle lever adjustmentNOTE:Adjust the engine idling speed before adjusting the
throttle lever free play.1. Loosen the locknut.
2. Turn the adjusting bolt until the throttle lever
free play is 3 ~ 5 mm.
3. Tighten the locknut.
U5KM60.book Page 89 Thursday, June 21, 2001 2:40 PM

8-107
EBU00570
Cable inspection and lubrication
WARNING
Inspect cables frequently and replace if dam-
aged. Corrosion can result when the outer cov-
ering of control cables becomes damaged.
Cables can also become frayed or kinked. Op-
eration of controls could be restricted, which
could cause an accident or injury.Lubricate the inner cables and the cable ends. If
the cables do not operate smoothly, ask a Yamaha
dealer to replace them.
Recommended lubricant:
Engine oil
U5KM60.book Page 107 Thursday, June 21, 2001 2:40 PM