Checking The Spark Plug - Yamaha YFZ45RB Owner's Manual

1. Quick fastener
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1. Quick fastener
To install the cowling
1. Place the cowling in the original position, and
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then tighten the quick fasteners.
2. Install panels C, B and A.
EBU29441

Checking the spark plug

The spark plug is an important engine component,
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which should be checked periodically, preferably
by a Yamaha dealer. Since heat and deposits will
cause any spark plug to slowly erode, the spark
plug should be removed and checked in accor-
dance with the periodic maintenance and lubrica-
tion chart. In addition, the condition of the spark
plug can reveal the condition of the engine.
The porcelain insulator around the center elec-
trode of the spark plug should be a medium-to-light
tan (the ideal color when the vehicle is ridden nor-
mally). If the spark plug shows a distinctly different
color, the engine could be operating improperly.
Do not attempt to diagnose such problems your-
self. Instead, have a Yamaha dealer check the ve-
hicle.
If the spark plug shows signs of electrode erosion
and excessive carbon or other deposits, it should
be replaced.
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