Fits all engines; cars, trucks, motorcycles, boat engines and other types of 2- or 4-stroke, single- or multi-cylinder gasoline engines.

Easily detect which cylinder is causing problems with this spark plug test light. Simply connect the spark plug detector between the spark plug and the spark plug wire, then start the engine.

Spark plug tester for small engines and vehicles to quickly and easily diagnose ignition, engine problems and defects, and troubleshoot spark plug connections, contact points, defective cables, etc.

The tool is double-sided to offer a straight connection and a 90-degree connection on one tool. With the engine running, the tool flashes a mirror image of the ignition spark.

Simply turn off the engine and connect the spark plug tester between the spark plug and the spark plug wire. If it works, the color of the light indicates the quality of the spark.