Checking The Spark Plug - Yamaha BIG BEAR 250 YFM25BZ Owner's Manual

EBU23213

Checking the spark plug

The spark plug is an important engine component,
which is easy to check. 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.
To remove the spark plug
1. Remove the spark plug cap.
8
1. Spark plug cap
2. Remove the spark plug as shown, with the
spark plug wrench included in the owner's tool
kit.
1. Spark plug wrench
To check the spark plug
1. Check that the porcelain insulator around the
center electrode of the spark plug is a medi-
um-to-light tan (the ideal color when the ATV
is ridden normally).
8-9