Spark Plug: Testing and Inspection

INSPECTION PROCEDURE





1. REMOVE IGNITION COILS.

2. INSPECT ELECTRODE INSULATION.



- Using a megger (insulation resistance meter), measure the insulation resistance.

Insulation resistance: 10 M Ohm or more

- If the resistance is less than specified, proceed to step 3.




3. REMOVE SPARK PLUGS USING A 16 MM PLUG WRENCH.

4. VISUALLY INSPECT SPARK PLUGS.
- Check the spark plug for thread damage and insulator damage.
- If abnormal. replace the spark plug.

Recommended spark plug:
GPK20R11 for ND
BKR6EP-11 for NGK

5. INSPECT ELECTRODE GAP.



- If the gap is greater than maximum. replace the spark plug.

Maximum gap (used spark plug): 1.3 mm (0.051 in)
Correct gap (new spark plug): 1.1 mm (0.043 in)

NOTE:
- Never attempt to adjust the gap on the used plug.
- 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.

Air pressure: Below 588 kPa (85 psi).
Duration: 20 seconds or less.

NOTE:
- Never use a wire brush for cleaning.
- If there are traces of oil, remove it with gasoline before using the spark plug cleaner.

7. INSTALL SPARK PLUGS.



- Using a 16 mm plug wrench, install the spark plug.

Torque: 18 Nm (13 ft.lb)

8. REINSTALL IGNITION COILS.