Operation CHARM: Car repair manuals for everyone.

Spark Plug: Testing and Inspection

CAUTION: Use care not to allow foreign matter to enter through plug holes.

INSPECTION
1. Check the spark plugs for the following:
Broken insulator
Worn electrode
Carbon deposits
Damaged or broken gasket
Burnt condition of porcelain insulator at spark gap.

NOTE: Dark deposits indicate too rich a fuel mixture, light (white) deposits indicate too lean a fuel mixture, advanced ignition timing or insufficient plug tightening

2. Check plug gap using a plug gap gauge and adjust if necessary.
ELECTRODE CLEARANCE
0.039 - 0.043in (1.0 - 1.1mm)