INSPECTION OF SPARK PLUGS NOTICE: • Never use a wire brush for cleaning. • Never attempt to adjust the gap on a used plug. • Spark plugs should be replaced every 60,000 miles (100,000 km). 1. INSPECT ELECTRODE If using a megger (insulation resistance meter): (a) Remove the high-tension cords. (See page IG-6) (b) Measure the insulation resistance. Correct insulation resistance: More than 10 MΩ If less than 10 MΩ, proceed to step 2. If not using a megger: (a) Quickly race the engine to 4,000 rpm five times. (b) Remove the spark plugs. (See procedure below) (c) Visually inspect the spark plugs. If the electrode is dry.....Okay If the electrode is wet.....Proceed to step 3 2. REMOVE SPARK PLUGS (a) Remove the high-tension cords. (See page IG-6) (b) Using a plug wrench(16 mm), remove the spark plugs.