Spark Plug Inspection
  1. Remove the spark plugs and inspect the electrodes and ceramic insulator.
    • Burned or worn electrodes may be caused by these conditions:
      • -
      Advanced ignition timing
      -
      Loose spark plug
      -
      Plug heat range too hot
      -
      Insufficient cooling
    • Fouled plugs may be caused by these conditions:
      • -
      Retarded ignition timing
      -
      Oil in combustion chamber
      -
      Incorrect spark plug gap
      -
      Plug heat range too cold
      -
      Excessive idling/low speed running
      -
      Clogged air cleaner element
      -
      Deteriorated ignition coils
  1. If the spark plug electrode is dirty or contaminated, clean the electrode with a plug cleaner.
    NOTE:
    • Do not use a wire brush or scrape the iridium electrode since this will damage the electrode.
    • When using a sand blaster spark plug cleaner, do not clean for more than 20 seconds to avoid damaging the electrode.