2007 YAMAHA RHINO 660 engine

8-75 1. V-belt case drain plug
1. Bouchon de vidange du carter de courroie trapézoïdale
1. Tapón de vaciado de la caja de la correa trapezoidal
EVU00780
V-belt case drain plug
The V-belt case drain plug is located under the
driver seat. (See page 4-45 for seat removal and
installation procedures.)
After riding in water deep enough to allow water to
enter the V-belt case, remove the drain plug to
drain any water from the case.NOTE:_ If water drains from the V-belt case after removing
the drain plug, have a Yamaha dealer inspect the
vehicle as the water may affect other engine parts. _
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8-79
WARNING
Do not start the engine when cleaning the
spark arrester, otherwise it could cause injury
to the eyes, burns, carbon monoxide poison-
ing, possibly leading to death, and start a fire.
Always let the exhaust system cool prior to
touching exhaust components.
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8-81
EVU00800
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. _
EE.book Page 81 Friday, August 4, 2006 12:02 PM

8-83 1. Throttle stop screw
1. Vis de butée de papillon des gaz
1. Tornillo de tope del acelerador
EVU00810
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 re-
sponds to the throttle.
2. Remove the seats. (See page 4-45 for seat
removal and installation procedures.)
3. Remove the console. (See page 8-21 for
console removal and installation proce-
dures.)
4. Connect the tachometer to the spark plug
lead, and then set the idle to the specified
idling speed by adjusting the throttle stop
screw. Turn the screw in direction a to in-
crease the engine speed, and in direction b
to decrease the engine speed.
Specified idle speed:
1,450–1,550 r/min
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8-85
5. Install the console.
6. Install the seats.
EVU00821
Valve clearance
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.
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8-103
EVU01490
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
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8-139
EVU01540
Troubleshooting charts
Starting problems or poor engine performance1. Fuel
Check if there is fuel
in the fuel tank.There is fuel.
No fuel.Fuel pump is
clogged.
Restart the engine.
No fuel.Supply fuel.
2. Compression
Use the electric
starter to see if
there is compression.There is compression.
Compression normal.
No compression.Ask a Yamaha dealer to
inspect.
3. Ignition
Remove the
spark plug and
check the electrodes.WetWipe clean with dry cloth.
DryAttach spark plug cap and
ground to chassis.Use the
electric starter.Spark is good.Ignition system is
normal.
Spark is weak.
Adjust the spark plug gap
or replace the spark plug. No spark.
Ask a Yamaha dealer to
inspect. 4. Battery
Use the electric starter.Engine turns over
quickly.Battery is good.
Engine turns over
slowly.Check the connections,
recharge.Check the
fuel flow.
Remove the fuel hose
from the fuel pump.
Ask a Yamaha dealer to
inspect.
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8-140
Engine overheatingNOTE:_ If it is difficult to get the recommended coolant, tap water can be temporarily used, provided that it is
changed to the recommended coolant as soon as possible. _
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.Wait until the
engine has cooled.
Check the coolant level in the
coolant reservoir and/or radiator.
Level is OK.Level is low, check the
cooling system for leakage.
No
leakage.Leakage.
Ask a Yamaha dealer to inspect
and repair the cooling system.Add coolant. (See NOTE.)
Restart the engine. If the engine overheats again, ask a
Yamaha dealer to inspect and/or repair the cooling system.
EE.book Page 140 Friday, August 4, 2006 12:02 PM