2004 YAMAHA WOLVERINE 400 engine

7-25
Exhaust system
The exhaust system on the ATV is very hot during
and following operation. To prevent burns, avoid
touching the exhaust system. Park the ATV in a
place where pedestrians or children are not likely
to touch it. Dry grass or brush or other combustible
material accumulated around the engine area
could catch fire.
WARNING
_ Do not touch the hot exhaust system. Do not
park the ATV during or after operation in a
place where others might be likely to touch it.
Keep the engine area free of dry grass, brush,
or other combustible material. Do not operate,
idle, or park the ATV in dry grass or other dry
ground cover. _
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7-35
Select a large, flat area off-road to become familiar
with your ATV. Make sure that this area is free of
obstacles and other riders. You should practice
control of the throttle, brakes, and turning tech-
niques in this area before trying more difficult ter-
rain. Always avoid riding on paved surfaces: the
ATV is designed for off-road use only, and han-
dling maneuvers are more difficult to perform on
pavement.
Set the parking brake and follow the instructions
on page 6-3 to start the engine. Once it has
warmed up you are ready to begin riding your
ATV. Remember that the engine and exhaust pipe
will be hot when riding and afterwards; do not al-
low skin or clothing to come in contact with these
components.
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7-37
With the engine idling, return the starter (choke) to
the closed position and shift the drive select lever
into the forward position, then release the parking
brake. Apply the throttle slowly and smoothly. The
centrifugal clutch will engage and you will start to
accelerate. If the throttle is applied too abruptly,
the front wheels may lift off the ground resulting in
a loss of directional control. Avoid higher speeds
until you are thoroughly familiar with the operation
of your ATV.
When slowing down or stopping, release the throt-
tle and apply the brakes smoothly and evenly. Im-
proper use of the brakes can cause the tires to
lose traction, reducing control and increasing the
possibility of an accident.
U5VH61.book Page 37 Friday, May 2, 2003 2:19 PM

8-1
EBU00516
PERIODIC MAINTENANCE AND
ADJUSTMENTPeriodic inspection, adjustment and lubrication will
keep your machine in the safest and most efficient
condition possible. Safety is an obligation of the
machine owner. The most important points of ma-
chine inspection, adjustment and lubrication are
explained on the following pages.
WARNING
Never service an engine while it is running.
Moving parts can catch clothing or parts of the
body, causing injury. Electrical components
can cause shocks or can start fires. Turn off
the engine when performing maintenance un-
less otherwise specified. Have a Yamaha deal-
er perform service if you are not familiar with
machine service.
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8-7
EBU00262
PERIODIC MAINTENANCE/LUBRICATION
ITEM ROUTINEINITIAL EVERY
1
month3
months6
months6
months1
year
Valves*Check valve clearance.
Adjust if necessary.
Cooling systemCheck coolant leakage.
Repair if necessary.
Replace coolant every 24 months.Spark plugCheck condition.
Adjust gap and clean.
Replace if necessary.Air filter elementClean.
Replace if necessary.Every 20–40 hours
(More often in wet or dusty areas.)
Carburetor*Check and adjust idle speed/starter operation.
Adjust if necessary.Crankcase breather
system*Check breather hose for cracks or damage.
Replace if necessary.Exhaust system*Check for leakage.
Tighten if necessary.
Replace gasket(s) if necessary.Fuel line*Check fuel hose for cracks or damage.
Replace if necessary.Engine oil
Replace. (Warm engine before draining.)Engine oil filter cartridge
Replace.Engine oil strainer*
Clean.Final gear oilCheck oil level/oil leakage.
Replace every 12 months.Front brake*Check operation/fluid leakage. (See NOTE page 8-8.)
Correct if necessary.Rear brakeCheck operation.
Adjust if necessary.U5VH61.book Page 7 Friday, May 2, 2003 2:19 PM

8-29 1. Engine oil filler cap
1. Bouchon de remplissage d’huile de moteur
1. Tapa del filtro 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
EBU10991
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. Remove panel F. (See page 8-27 for panel
removal and installation procedures.)
2. Place the ATV on a level surface.
3. Start the engine, warm it up for several min-
utes, and then turn it off.
4. Wait a few minutes until the oil settles.
5. Remove the engine oil filler cap and wipe off
the dipstick with a clean rag.
6. 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. _
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8-31 1. Engine oil drain bolt
1. Boulon de vidange de l’huile de moteur
1. Perno de drenaje del aceite de motor
7. If the engine oil is at or below the minimum
level mark, add sufficient oil of the recom-
mended type to raise it to the correct level.
8. Insert the dipstick into the oil filler hole, and
then tighten the oil filler cap.
9. Install the panel.
To change the engine oil (with or without oil fil-
ter cartridge replacement)
1. Remove panel F. (See page 8-27 for panel
removal and installation procedures.)
2. Start the engine, warm it up for several min-
utes, and then turn it off.
3. Place an oil pan under the engine to collect
the used oil, and then remove the engine oil
filler cap.
4. Remove the engine oil drain bolt to drain the
oil from the crankcase.
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8-35 1.
O-ring
1. Joint torique
1. Junta tórica
1. Torque wrench
1. Clé dynamométrique
1. Llave
7. Apply a light coat of engine oil to the O-ring of
the new oil filter cartridge.NOTE:_ Make sure the O-ring is seated properly. _8. Install the new oil filter cartridge with an oil fil-
ter wrench, and then tighten it to the specified
torque with a torque wrench.
9. Install panel E.
10. Install the engine oil drain bolt, and then tight-
en it to the specified torque. Tightening torque:
Oil filter cartridge:
17 Nm (1.7 m·kgf)
Tightening torque:
Engine oil drain bolt:
23 Nm (2.3 m·kgf)
U5VH61.book Page 35 Friday, May 2, 2003 2:19 PM