Spark Plug: Testing and Inspection

CAUTION:

- Never use a wire brush for cleaning.

- Never attempt to adjust gap on used plug.

- Spark plugs should be replaced every 60,000 miles (100,000 km).

1. INSPECT ELECTRODE

If using a megger (insulation resistance meter):

(a) Remove the high-tension cords.

(b) Measure the insulation resistance.

Correct insulation resistance: More than 10 Mohms

If less than 10 Mohms, proceed to step 2.

If not using a megger:

(a) Quickly race the engine to 4,000 rpm five times.

(b) Remove the spark plugs.

2. REMOVE SPARK PLUGS

(a) Remove the high-tension cords.

(b) Using a plug wrench(1 6 mm), remove the spark plugs.

3. VISUALLY INSPECT SPARK PLUGS

Check the spark plug for thread or insulator damage.

If abnormal, replace the plug.

Recommended spark plugs:

7M-GE ND PQ16R
NGK BCPR5EP11

7M-GTE ND PQ20R-P8
NGK BCPR6EP-N8

4. INSPECT ELECTRODE GAP

Maximum electrode gap:
7M-GE 1.3 mm (0.051 in.)
7M-GTE 1.0 mm (0.039 in.)

If the gap is greater than maximum, replace the plug.

Correct electrode gap of new plug:
7M-GE 1.1 mm (0.043 in.)
7M-GTE 0.8 mm (0.031 in)

If adjusting the gap of a new plug, bend only the base of the ground electrode, do not touch the tip.

5. 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 6 kg/cm2 (85 psi, 588 kPa) Duration: 20 seconds or less

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

6. INSTALL SPARK PLUGS

(a) Using a plug wrench (16mm), install and torque the spark plugs.

Torque: 180 kg-cm (13 ft-lb, 18 N.m)

(b) Install the high-tension cords.