Spark Plug: Testing and Inspection

SPARK PLUGS INSPECTION

NOTICE:
- Never use a wire brush for cleaning.
- Never attempt to adjust the electrode gap on used a 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 3.

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

Simple Method:
(a) Quickly race the engine to 4,000 rpm 5 times.
(b) Remove the spark plug. (See step 3)
(c) Visually check the spark plug.
If the electrode is dry ... OK
If the electrode is wet... Proceed to step 4
(d) Reinstall the spark plug. (See step 7)
3. REMOVE SPARK PLUGS
Using a 16 mm plug wrench, remove 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:

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/sq.cm. 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
(a) Connect the high-tension cords to the spark plugs.

(b) Secure the high-tension cords with the cord clamps as shown in the illustration.