What Should I Set My Spark Plug Gap To

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 the spark plug gap is too big?

One of the key factors that makes a spark plug work well, or not, is the size of the gap between the electrodes. … However, if the spark plug gap is too large, the spark is unlikely to consistently “jump” across the long distance between electrodes, thus leading to a rough-running engine or one that doesn’t run at all.

Should I adjust spark plug gap?

The incorrect plug gap for your engine can contribute to a high rate of misfires, loss of power, plug fouling, poor fuel economy and accelerated plug wear. … It is always best to check the gap against the manufacturer’s specifications.