What Does Gapping a Spark Plug Mean

The gap between the center and side electrodes of a spark plug must be an exact distance; otherwise, your plugs don’t fire efficiently. Adjusting the distance between the two electrodes is called gapping your spark plugs. You need a feeler gauge to gap your spark plugs properly.

What is the reason for gapping spark plugs?

When replacing spark plugs, ensuring that the plugs have the proper gap is critical to engine performance. The gap is the distance between the center and side electrodes, set so arcing occurs at the proper voltage that ignites the fuel and generates the combustion that makes the engine run.

Does gapping a spark plug matter?

The Spark-Plug Gap One of the key factors that makes a spark plug work well, or not, is the size of the gap between the electrodes. If the gap is too small, the spark will likely be too weak and cause the engine to run poorly or with poor efficiency.