Spark Plug: Testing and Inspection

Spark Plug Inspection:

1. Inspect the electrodes and ceramic insulator for burned or worn electrodes, which 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. Adjust the gap with a suitable gapping tool.

Example Of Worn Plug:

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

4. Apply a small quantity of anti-seize compound to the plug threads.

Recommended Spark Plugs

For all normal driving:
ZFR5F-11 (NGK)
KJ16CR-L11 (Nippondenso)

For hot climates or continuous high speed driving:
ZFR6F-11 (NGK)
KJ20CR-L11 (Nippondenso)


5. Screw the plugs into the cylinder head finger-tight, then torque them to 18 Nm (13 lb-ft).