Spark Plug Chart

"Used Plugs Tell a Story". Let the condition of your spark plugs show you where you can improve your engine's performance. An illustrated guide by Champion®.

Normal Correct heat range. Service or replace.			Ash Deposits Derived from oil and/or fuel additives.
Worn Out Replace with new Champions.			Preignition Check plug heat range and engine adjustments.
Carbon Deposits Check correct heat range, rich mixture or weak ignition.			Core Nose Fracturing Improper gap setting techniques or detonation.
Splashed Deposits Service and reinstall.			Too Hot Check for correct heat range and engine adjustments.
Oil Deposits Poor oil control.			High Speed Glazing Replace with colder heat range.