- Purpose: The engine spark plug tester is a diagnostic tool for engines with spark plugs. It quickly diagnoses ignition problems, engine misfires, or fuel supply faults in cars, outboard engines, and other equipment. - Easy to use: Attach the tester to the spark plug and the ignition cable. When the spark fires, the tester reflects the spark and lights up. - Light indicator: The indicator shows the spark color clearly, helping you detect a weak spark, battery issues, or inconsistent ignition. - Versatile compatibility: Works with all spark plug engines, including cars, motorcycles, lawn mowers, boat engines, chainsaws, and other small or large engines. - Use scenarios: - Troubleshooting a car with a misfire to confirm ignition spark presence. - Diagnosing a lawn mower or chainsaw that won’t start to distinguish spark vs fuel problems. - Field testing a boat or outboard engine to verify ignition spark before proceeding with repairs.