Thumpstar KXD - Spark Plug Coloring Guidelines

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SPARK PLUG COLORING GUIDELINES
Condition Spark Plug Appearance Mixture
Normal Dark Brown to Light
Tan color with Dry
Electrode
Correct
Overheating (Lean) Light Gray or White
Color
Lean
Wet (Rich) Wet or Sooty Rich
Remember that in addition to improper jetting:
•Aleanconditioncanbecausedbyairleaksintheinlettractorexhaust
system, the passage of too much air because of the use of the wrong air
cleaner, use of a less-restrictive aermarket exhaust system, or a hole or
holes (deliberate or unintentional) in the air box.
•Arichconditioncanbecausedbyapluggedordirtyaircleaner,useofa
more-restrictive aermarket exhaust system, a clogged spark arrester, or
excessive oil on the air cleaner. Excessive smoking will occur.
Spark Plug
Center Electrode
Side Electrode
Insulator