How to Clean Spark Plugs

Spark plugs are found in all engines, whether it be your car, lawn mower or generator. Like most any engine part, spark plugs need to be checked periodically and either cleaned or replaced. You can get more life out of a spark plug, and save a few dollars in the process, by cleaning spark plugs rather than replacing them.

Difficulty: Moderately Easy

Instructions

1. Remove spark plugs from the engine by pulling off the wires and unscrewing the spark plugs from their seats. If the engine is hot, allow it to cool before removing the spark plugs.

2. Scrub the threads with a fine wire brush or steel wool to loosen any dirt particles. Do not use a wire brush or steel wool on the ceramic insulator of the spark plugs.

3. Spray the spark plug with spark plug cleaner or brake cleaner. Wipe with a soft cloth to remove any oil or debris.

4. Use a fine diamond file to clean the contact end of the spark plug. Re-gap the plug following manufacturer specifications.

5. Insert the clean spark plugs back into the cylinder, tighten and reattach wires.

Tips & Warnings

• As spark plugs fire in a certain order, it is best to take out one plug at a time, clean and replace before moving on to the next.
• Use a small piece of folded 400 grit wet or dry sandpaper to clean between the center and ground electrodes (the area where you gap the spark plug).
• Have your engine checked if the ends of the spark plugs are blackened, or if you inspect the plugs regularly and they are dirty at each inspection.
• Replace any spark plugs that cannot be properly cleaned.