Spark Plug: Testing and Inspection
SPARK PLUGS INSPECTIONNOTICE:
^ Never use a wire brush for cleaning.
^ Never attempt to adjust the electrode gap on a used spark plug.
^ Spark plugs should be replaced every 100,000 km (60,000 miles).
1. REMOVE IGNITION COILS AND IGNITION CABLES FROM THE SPARK PLUGS.
- Disconnect high-tension cords from ignition coils on the LH heads and from the spark plugs on the RH head.
- Refer to Ignition Cable inspection procedures.
- Disconnect the 3 ignition coil connectors.
- Remove the 3 bolts and 3 ignition coils from the LH cylinder head.
2. INSPECT ELECTRODE INSULATION
- Using a megger (insulation resistance meter), measure the insulation resistance.
Correct insulation resistance: 10 M Ohm or more
- If the resistance is less than specified, inspect and replace spark plug.
HINT: If a megger is not available, the following simple method of inspection provides fairly accurate results.
- Quickly race the engine to 4,000 rpm 5 times.
- Remove the spark plug. (See step 3)
- Visually check the spark plug.
- If the electrode is dry...OK
- If the electrode is wet...Proceed to step 4.
- Reinstall the spark plug. (See step 7)
3. REMOVE SPARK PLUGS
- Using a 16 mm plug wrench, remove the 6 spark plugs from the RH and LH cylinder heads.
4. VISUALLY INSPECT SPARK PLUGS
- Check the spark plug for thread damage and insulator damage.
- If abnormal, replace the spark plug.
Recommended spark plug:
ND: PK20TR11
NGK: BKR6KPB11
5. INSPECT ELECTRODE GAPS
Maximum gap for used spark plug: 1.3 mm (0.051 in.)
NOTE: If the gap is greater than maximum, replace the spark plug. Never attempt to adjust the gap on the used plug.
Correct gap for new spark plug: 1.1 mm (0.043 in.)
NOTE: If adjusting the gap of a new spark plug, bend only the base of the ground electrode. Do not touch the tip.
6. CLEAN SPARK PLUGS
- If the electrode has traces of wet carbon, allow it to dry and then clean with a spark plug cleaner.
HINT: If there are traces of oil, remove it with gasoline before using the spark plug cleaner.
Air pressure: Below 588 kPa (6 kgf/cm2, 85 psi)
Duration: 20 seconds or less
7. REINSTALL SPARK PLUGS
- Using a 16 mm plug wrench, install the 6 spark plugs to the RH and LH cylinder heads.
Torque: 18 Nm (180 kgf.cm, 13 ft.lb)
8. REINSTALL IGNITION COILS