Spark Plug: Testing and Inspection

Operational Inspection (Spark Test)
1. Remove the spark plug.
2. Connect the spark plug to a high-tension lead.




3. Hold the high-tension lead and spark plug with insulated pliers 5-10 mm (0.20-0.39 in) from a ground.
4. Crank the engine and verify that there is a strong blue spark.
5. Replace the spark plug or high tension lead as necessary if not as specified.









Visual Inspection
Check the following points. If a problem is found, replace the spark plug.
- Damaged insulation
- Worn electrodes
- Carbon deposits
If cleaning is necessary, use a plug cleaner. Clean the upper insulator, also.
- Damaged gasket
- Burnt

Plug gap: 1.1-1.7 mm (0.044-0.066 in)

CAUTION: The electrode is platinum coated. The following can scratch its platinum coating and impair its performance.
- Adjusting the plug gap.
- Using a wire brush to clean the electrode.
- Using a plug cleaner for more than twenty (20) seconds, or at more than 588 kPa (6 kgf/cm2, 85 psi).