For Spark Plug Gap?

For most racing applications, you usually want the plug gap to be between 0.020 and 0.040 of an inch. Most engine builders seem to settle around 0.035 of an inch. Factors such as the type of ignition you run, cylinder heads, fuel and even timing can affect how much gap will work best for you.

What happens if a spark plug gap is too small?

The Spark-Plug Gap

If the gap is too small, the spark will likely be too weak and cause the engine to run poorly or with poor efficiency. ... A spark-plug gap gauge both measures and adjusts the gap and is inexpensive and simple to use.

Is spark plug gap necessary?

Spark plugs require a precise gap to ensure proper ignition of the air/fuel mixture, and gapping them requires appropriate tools for your vehicle's specific plugs. Therefore, if your spark plugs need replacing, go out and pick up not only the proper plugs but the tools that will make gapping them easier.