2004 Yamaha Motorsports Big Bear 400 4x4 Owners Manual - Page 123

2004 Yamaha Motorsports Big Bear 400 4x4 Manual

Page 123 highlights

EBU00862 EBU11820 Axle boots Check the protective boots for holes or tears. If any damage is found, have them replaced by a Yamaha dealer. 1. Axle boot (× 2) Spark plug 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. For example, a very white center electrode porcelain color could indicate an intake air leak or carburetion problem for that cylinder. Do not attempt to diagnose such problems yourself. 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 electrode erosion becomes excessive, you should replace the spark plug with one of the proper type. Standard spark plug: DR8EA (NGK) 1. Axle boot (× 2) 8-14

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8-14
EBU00862
Axle boots
Check the protective boots for holes or tears.
If any damage is found, have them replaced
by a Yamaha dealer.
1.
Axle boot (
×
2)
1.
Axle boot (
×
2)
EBU11820
Spark plug inspection
The spark plug is an important engine compo-
nent and is easy to inspect. The condition of
the spark plug can indicate the condition of
the engine.
For example, a very white center electrode
porcelain color could indicate an intake air
leak or carburetion problem for that cylinder.
Do not attempt to diagnose such problems
yourself.
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 electrode erosion becomes ex-
cessive, you should replace the spark plug
with one of the proper type.
Standard spark plug:
DR8EA (NGK)