Spark Plug: Testing and Inspection

INSPECTION




1. Check spark plugs for the following:
1. Broken insulator
2. Worn electrode
3. Carbon deposits
4. Damaged or broken gasket
5. Condition of the porcelain insulator at the tip of the spark plug

ANALYZING SPARK PLUG



Engine conditions can be analyzed by the tip deposits near the electrode.

SPARK PLUG TEST



1. Remove the spark plug and connect to the spark plug cable.
2. Ground the spark plug outer electrode, and crank the engine.
3. Check to be sure that there is an electrical discharge between the electrodes at this time.




4. Check the spark plug gap using a wire gap gauge, and adjust if necessary.

Standard value: 1.0-1.1 mm (0.039-0.043 in.)