Spark Plug: Testing and Inspection

Spark Plug Inspection:

1. Inspect the electrodes and ceramic insulator for:
Burned or worn electrodes may be caused by:
^ Advanced ignition timing
^ Loose spark plug
^ Plug heat range too low
^ Insufficient cooling

Fouled plug may be caused by:
^ Retarded ignition timing
^ Oil in combustion chamber
^ Incorrect spark plug gap
^ Plug heat range too high
^ Excessive idling/low speed running
^ Clogged air cleaner element
^ Deteriorated ignition coil or ignition wires

Checking Spark Plug Electrode Gap:

2. F22A1/H23A1 engine: Adjust the gap with a suitable gapping tool.

H22A1 engine: Make sure that the 1.3 mm (0.051 in) plug gauge does not go into the gap for the platinum tip plug. If the gauge goes into the gap, do not attempt to adjust the side electrode; replace the plug with a new one.

Checking Spark Plug Electrode Gap (Platinum Plug):

3. Replace the plug if it is fouled or worn.

NOTE: Use only the spark plugs listed below.

Spark Plug Application Chart:

4. Apply a small quantity of anti-seize compound to the plug threads.
5. Screw the plugs into the cylinder head finger-tight, then torque them to 18 N.m (1.8 kg-m, 13 lb-ft).