2004 YAMAHA WOLVERINE 350 check engine

8-19 1. Engine oil filler cap
1. Bouchon de remplissage d’huile de moteur
1. Tapa de relleno de aceite de motor
1. Maximum level mark 2. Minimum level mark
1. Repère de niveau maximum 2. Repère de niveau minimum
1. Marca de nivel máximo 2. Marca de nivel mínimo
EBU14540
Engine oil and oil filter cartridge
The engine oil level should be checked before
each ride. In addition, the oil must be changed and
the oil filter cartridge replaced at the intervals
specified in the periodic maintenance and lubrica-
tion chart.
To check the engine oil level
1. Place the ATV on a level surface.
2. Start the engine, warm it up for several min-
utes, and then turn it off.
3. Wait a few minutes until the oil settles.
4. Remove the engine oil filler cap and wipe off
the dipstick with a clean rag.
5. Insert the dipstick in the oil filler hole (without
screwing it in), and then remove it again to
check the oil level.NOTE:_ The engine oil should be between the minimum
and maximum level marks. _
U5UH60.book Page 19 Wednesday, October 8, 2003 9:05 AM

8-29
‘1. Final gear oil
2. Final gear oil filler bolt
3. Proper oil level
1. Huile de transmission finale
2. Boulon de remplissage d’huile du carter de transmission finale
3. Niveau correct
1. Aceite de la transmisión final
2. Perno del orificio de llenado de aceite de la transmisión final
3. Nivel de aceite adecuado
9. Start the engine and warm it up for several
minutes. While warming up, check for oil
leakage. If oil leakage is found, turn the en-
gine off immediately and check for the cause.
10. Turn the engine off, and then check the oil
level and correct it if necessary.
EBU11452
Final gear oil
Final gear oil measurement
1. Place the machine on a level surface.
2. Remove the oil filler bolt, and then check the
oil level in the final gear case.NOTE:_ The oil level should be at the brim of the filler hole. _3. If the oil is below the brim of the filler hole,
add sufficient oil of the recommended type to
raise it to the correct level.CAUTION:_ Be sure no foreign material enters the final
gear case. _4. Install the oil filler bolt.
U5UH60.book Page 29 Wednesday, October 8, 2003 9:05 AM

8-55
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 air filter element mainte-
nance is performed, check the air inlet to the filter
case for obstructions. Check the air filter case rub-
ber 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. _
U5UH60.book Page 55 Wednesday, October 8, 2003 9:05 AM

8-57 1. V-belt cooling duct check hose
1. Flexible de contrôle du conduit de refroidissement de la courroie
trapézoïdale
1. Manguera de comprobación del conducto de enfriamiento de
la correa trapezoidal
1. V-belt case drain plug
1. Boulon de vidange du carter de courroie trapézoïdale
1. Tapón de drenaje de la caja de la correa trapezoidal
EBU06411
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.
EBU08741
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. _
U5UH60.book Page 57 Wednesday, October 8, 2003 9:05 AM

8-111
EBU04400Troubleshooting chart1. Fuel
Check if there is fuel
in the fuel tank.There is fuel.Turn the fuel cock
lever to “OFF”.No fuel.Fuel cock is
clogged.
Clean the
fuel cock. Some fuel.Turn the fuel cock
lever to “RES”.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 battery lead connections,
and charge the battery if necessary.Check the
fuel flow.
Turn the fuel cock
lever to “ON”.
Remove the fuel hose
from the fuel cock.
U5UH60.book Page 111 Wednesday, October 8, 2003 9:05 AM