2004 YAMAHA WOLVERINE 450 Spark plug

Tire wear limit......................................5-31
OPERATION ...........................................6-1
Starting a cold engine ...........................6-3
Starting a warm engine .........................6-9
Warming up...........................................6-9
Drive select lever operation and
reverse driving ..................................6-11
Engine break-in ...................................6-17
Parking ................................................6-19
Parking on a slope ..............................6-21
Accessories and loading .....................6-23
RIDING YOUR ATV..................................7-1
Getting to know your ATV .....................7-3
Ride with care and good judgement .....7-5
Be careful where you ride ...................7-27
Turning your ATV ................................7-39
Climbing uphill.....................................7-45
Riding downhill ....................................7-55
Crossing a slope .................................7-59
Crossing through shallow water ..........7-63
Riding over rough terrain ....................7-69
Sliding and skidding ............................7-71
What to do if ........................................7-75
What to do...........................................7-75
67
PERIODIC MAINTENANCE AND
ADJUSTMENT ........................................ 8-1
Owner’s manual and tool kit ................. 8-3
Periodic maintenance/lubrication.......... 8-7
Panel removal and installation............ 8-15
Engine oil and oil filter cartridge ......... 8-31
Final gear oil ....................................... 8-41
Differential gear oil.............................. 8-47
Cooling system ................................... 8-53
Changing the coolant.......................... 8-57
Axle boots ........................................... 8-63
Spark plug inspection ......................... 8-65
Air filter element cleaning ................... 8-71
V-belt cooling duct check hose ........... 8-79
V-belt case drain plug ......................... 8-79
Carburetor adjustment ........................ 8-81
Idle speed adjustment ........................ 8-83
Valve clearance adjustment ............... 8-85
Throttle lever adjustment .................... 8-87
Front brake pad check ........................ 8-89
Rear brake pad check ........................ 8-91
Inspecting the brake fluid level ........... 8-93
Brake fluid replacement ...................... 8-97
Front brake lever free play.................. 8-99
Rear brake lever adjustment ............ 8-101
Brake pedal position adjustment ...... 8-101
8
U5ND61.book Page 2 Thursday, June 5, 2003 7:02 PM

3-1
EBU00032
DESCRIPTION AND MACHINE
IDENTIFICATION1. Rear shock absorber
assembly spring preload
adjusting ring
2. Storage compartment
and tool kit
3. Spark plug
4. Rear brake fluid reservoir
5. Radiator cap
6. Front shock absorber
assembly spring preload
adjusting ring
7. V-belt case
8. Brake pedal
9. Front shock absorber
assembly spring preload
adjusting ring
10. Fuel cock
11. Air filter case
12. Fuses13. Tail/brake light
14. V-belt cooling duct check
hose
15. Coolant reservoir
16. Oil filter cartridge
17. Engine oil dipstick
18. Rear brake lever
19. Left handlebar switches
20. Starter (choke)
21. Horn switch
22. Drive select lever
23. Speedometer unit
24. Main switch
25. Fuel tank cap
26. Auxiliary DC jack
27. Right handlebar switch
28. Throttle lever
29. Front brake leverNOTE:The machine you have purchased may differ
slightly from those shown in the figures of this
manual.
U5ND61.book Page 1 Thursday, June 5, 2003 7:02 PM

8-7
EBU00262
PERIODIC MAINTENANCE/LUBRICATION
ITEM ROUTINEWhichever
comes firstINITIAL EVERY
km 320 1,200 2,400 2,400 4,800
hours 20 75 150 150 300
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.
Retighten 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 oil
Check oil level/oil leakage.
Replace every 12 month.Differential gear oil
Front brake*Check operation/fluid leakage. (See NOTE page 8-8.)
Correct if necessary.Rear brake*Check operation/fluid leakage.(See NOTE page 8-8.)
Correct if necessary.U5ND61.book Page 7 Thursday, June 5, 2003 7:02 PM

8-65 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 pages 8-17–8-19 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.
U5ND61.book Page 65 Thursday, June 5, 2003 7:02 PM

8-67
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.
Do not attempt to diagnose such problems your-
self.
Instead, take the ATV to a Yamaha dealer. You
should periodically remove and inspect the spark
plug because heat and deposits will cause the
spark plug to slowly break down and erode. If elec-
trode erosion becomes excessive, or if carbon and
other deposits are excessive, you should replace
the spark plug with the specified plug.
Specified spark plug:
DR8EA (NGK)
U5ND61.book Page 67 Thursday, June 5, 2003 7:02 PM

8-69 a. Spark plug gap
a.Écartement des électrodes
a. Huelgo de la bujía
Installation
1. Measure the electrode gap with a wire thick-
ness gauge and, if necessary, adjust the gap
to specification.
2. Clean the gasket surface. Wipe off any grime
from the threads.
3. Install the spark plug and tighten it to the
specified torque.NOTE:_ If a torque wrench is not available when you are in-
stalling a spark plug, a good estimate of the correct
torque is 1/4 to 1/2 turn past finger tight. Have the
spark plug tightened to the specified torque as
soon as possible. _4. Install the spark plug cap.
5. Install the panel. Spark plug gap:
0.6–0.7 mm
Tightening torque:
Spark plug:
17.5 Nm (1.75 m·kgf)
U5ND61.book Page 69 Thursday, June 5, 2003 7:02 PM

8-83 1. Throttle stop screw
1. Vis d’arrêt de l’accélérateur
1. Tornillo de tope del acelerador
EBU12580
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 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.
4. Install the panel. Specified idle speed:
1,450–1,550 r/min
U5ND61.book Page 83 Thursday, June 5, 2003 7:02 PM

8-133
EBU00724Troubleshooting chart
Starting problems or poor engine performance1. 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 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.Check the
fuel flow.
Turn the fuel cock
lever to “ON”.
Remove the fuel hose
from the fuel cock.
U5ND61.book Page 133 Thursday, June 5, 2003 7:02 PM