Honda NSS300 Forza - Owner's Manual > Spark Plug

Checking & Changing Spark Plug

For the recommended spark plug, see "Specifications".

Use only the recommended type of spark plug in the recommended heat range.

NOTICE Using spark plugs with an improper heat range can cause engine damage.

1. Place your scooter on its centre stand on a level surface.

2. Pull the floor mat off.

3. Remove the screw.

4. Remove the plug maintenance lid by inserting a flat head screwdriver covered with a protective cloth into the slit on the floor.

5. Disconnect the spark plug cap.

6. Clean any dirt from around the spark plug base.

7. Remove the spark plug using the spark plug wrench provided in the tool kit.

8. Inspect the electrodes and centre porcelain for deposits, erosion or carbon fouling.

• If the erosion or deposit is heavy, replace the plug.
• Clean a carbon or wet-fouled plug with a plug cleaner, otherwise use a wire brush.

9. Check the spark plug gap using a wiretype feeler gauge.

• If adjustment is necessary, bend the side electrode carefully.

10. Make sure the plug washer is in good condition.

11. With the plug washer attached, thread the spark plug in by hand to prevent cross-threading.

12. Tighten the spark plug:

• If the old plug is good: 1/8 turn after it seats
• If installing a new plug, tighten it twice to prevent loosening:
  1. First, tighten the plug: NGK: 1/2 turn after it seats.
  2. Then loosen the plug.
  3. Next, tighten the plug again: 1/8 turn after it seats.

NOTICE Improperly tightened spark plug can damage the engine.

If a plug is too loose, a piston may be damaged. If a plug is too tight, the threads may be damaged.

13. Reinstall the spark plug cap. Take care avoid pinching any cables or wires.

14. Install the parts in the reverse order of removal.

See also: