Spark Plug: Testing and Inspection

SPARK PLUGS INSPECTION

NOTICE:
- 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. DISCONNECT HIGH-TENSION CORDS FROM SPARK PLUGS.




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

Standard correct insulation resistance:
10 M Ohms or more

- If the resistance is less than specified, proceed to step 7.

HINT: If a megger is not available, the following simple method of inspection provides fairly accurate results.




Simple Method:
- Quickly race the engine 5 times to 4,000 rpm
- 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, install the 6 spark plugs.

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 PK16R11, NGK BKR5EP11




5. INSPECT ELECTRODE GAP.

Maximum electrode gap for used spark plug:
1.3 mm (0.051 in.)

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

Correct electrode gap for new spark plug:
1.1 mm (0.043 in.)

NOTICE:
- If adjusting the gap of a new spark plug, bend only the base of the ground electrode.
- Do not touch the tip.
- Never attempt to adjust the gap on the used plug.




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 (6 kgf/cm2, 85 psi)

Duration: 20 seconds or less

HINT: If there are traces of oil, remove it with gasoline before using the spark plug cleaner.




7. REINSTALL SPARK PLUGS.

Torque: 18 N.m (180 kgf.cm, 13 ft.lbf)

8. RECONNECT HIGH-TENSION CORDS TO SPARK PLUGS.