Spark Plug Inspection

Remove the ignition coils (see IGNITION COIL REMOVAL/INSTALLATION )
Remove the spark plugs, then inspect the electrodes and the ceramic insulator
- Burned or worn electrodes may be caused by these conditions
  - Advanced ignition timing
  - Loose spark plug
  - Plug heat range too hot
  - Insufficient cooling
- Fouled plugs may be caused by these conditions
  - 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
Fig 1: Identifying Spark Plug
Courtesy of AMERICAN HONDA MOTOR CO., INC.
If the spark plug electrode is dirty or contaminated, clean the electrode with a plug cleaner
NOTE:
- Do not use a win? brush or scrape the indium electrode since this will damage the electrode
- When using a sand blaster spark plug cleaner, do not clean for more than 20 seconds to avoid damaging the electrode
Replace the plug at the specified interval, or if the center electrode is rounded (A), or if the spark plug gap (B) is out of specification Use only the spark plugs listed
NOTE: Do not adjust the gap of indium tip plugs

J35Z6 engine

Spark Plug

NGK ILZKR7B11

Electrode Gap

Standard (New) 1./0-1.1 mm (0.039-0.043 in)

J37A4 engine

Spark Plug

DENSO SXU22HCR11S

Electrode Gap

Standard (New) 1.0-1.1 mm (0.039-0.043 in)

Fig 2: Identifying Spark Plug Gap
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Apply a small amount of anti-seize compound to the plug threads, and screw the plugs into the cylinder head, finger-tight Torque them to 22 Nm (2.2 kgf.m, 16 lb.ft)