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 plugs 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

Spark Plug Inspection:

2. D16Y7/D16Y8 engine: Adjust the gap with a suitable gapping tool, and replace the plug if the center electrode is rounded as shown above.

Spark Plug Gap Setting (Platinum Plugs):

3. B16A2 engine: For platinum tip plug, do not adjust the gap; replace the spark plug if the gap is out of specifications or if the center electrode is rounded.

Spark Plug Inspection:

NOTE: Use only the spark plugs listed above.

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