Spark Plug Inspection - L15A5 (FO model)

L15A5 engine (FO model)

1.Inspect the electrodes and ceramic insulator.

  • Burned or worn electrodes may be caused by:
    • Advanced ignition timing
    • Loose spark plug
    • Plug heat range too hot
    • Insufficient cooling

  • Fouled plug may be caused by:
    • 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


2.Do not adjust the gap (A) of iridium tip plugs; replace the spark plug if the gap is out of specification.

Electrode Gap 
Standard (New): 1.2-1.3 mm (0.042-0.051 in.) 


3.Replace the plug at the specified interval, or if the center electrode is rounded (A). Use only the spark plugs as listed.

Spark Plugs 


4.Apply a small quantity of anti-seize compound to the plug threads, and screw the plugs into the cylinder head finger-tight. Then torque them to 18 N·m (1.8 kgf·m, 13 lbf·ft).