What You Should Know About Spark Plugs, Their Adjustment, and Their Replacement (2022)

6/24/2022


Frequently Asked Questions
 

1. What happens if the spark plug gap is too small?

If the spark plug gap in your vehicle is too small, the spark won’t have enough exposure to the fuel mixture to properly ignite it. The spark generated by a smaller spark plug gap is sometimes too weak to start the engine. Several engine issues result from a spark plug gap that is too small.

2. Spark plug gap too small symptoms

Symptoms of a spark plug gap that is too small include continuous cylinder misfires (which can sound like knocking or popping), hard starting (if all spark plugs have a gap that’s too small), engine hesitation, and rough idling. A way to recognize a spark plug with a too-small gap on sight is that it will be black or wet due to unburned fuel. 

3. Is a smaller spark plug gap better?

A smaller spark plug gap is not better because a gap that is too small can prevent the vehicle’s fuel mixture from being ignited and create engine performance issues. While making a spark plug gap that’s too big smaller can be helpful, making the gap smaller, in general, isn’t better for your vehicle.

4. Does the spark plug gap matter?

Yes, the spark plug gap matters. If your vehicle’s spark plug gap is too big or too small, this can cause issues with engine performance or even prevent your engine from starting. Having the ideal spark plug gap in your vehicle ensures your car runs more smoothly.

5. What happens if the spark plug gap is too big?

If the spark plug gap in your vehicle is too big, the spark plugs will need a higher voltage to get the ignition spark to cross the gap. The engine can’t always provide the extra voltage needed to cross the gap, so the spark is weaker and won’t ignite your fuel mixture properly. This can cause engine performance issues.

6. Spark plug gap too big symptoms

Much like with a spark plug gap that’s too small, symptoms of a spark plug gap that is too big include cylinder misfires, rough idling, engine hesitation, and the engine not starting. You can identify a spark plug with a gap that’s too big on sight by it being wet or black due to unburned fuel or completely coated in a substance that looks like dirt.

7. How does the spark plug gap affect performance?

A spark plug’s gap affects performance by changing how an engine starts, runs, and idles. With an ideal spark plug gap, things will run smoothly. With a gap that’s too big or too small, you’ll notice quickly that your engine (and, by extension, riding experience) is rougher and riddled with hesitancy and strange engine noises.

8. Spark plug gap chart

A spark plug gap chart can be used to determine what the ideal spark plug gap is for specific vehicles or engines. It can also be a reference for measurement conversions when determining the size of an existing spark plug gap using a gauge. Anyone attempting to measure or change a spark plug gap should have a spark plug gap chart handy.