Spark Plug Inspection - Yamaha BEAR TRACKER YFM250XS Owner's Manual

EBU11820

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 porce-
lain color could indicate an intake air leak or carbu-
retion 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 elec-
trode erosion becomes excessive, you should re-
place the spark plug with one of the proper type.
Standard spark plug:
DR7EA (NGK)
8-27