Spark Plug: Testing and 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 {0.20-39 in} from a ground.
4. Crank the engine and verify that there is a strong blue spark. If not, replace the spark plug or high-tension lead as necessary.





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 or a wire brush. Clean the upper insulator, also.
^ Damaged gasket
^ Burnt

Plug gap: 1.0-1.1 mm {0.040-0.043 in}