Spark plug tester Key benefits Quickly verify whether a spark plug is producing a consistent spark, saving time and avoiding unnecessary part replacement. Helps identify whether an engine problem is caused by the spark plug or by other ignition components, reducing diagnostic time and repair cost. Compact, handheld design lets you observe the spark gap safely and easily during testing. What it does Visual spark tester that connects to spark plug leads and shows if a spark is present across the electrode gap. Diagnoses spark-related faults such as intermittent sparks, misfires, defective contact points, and poor wiring connections that cause engine stumbling or power loss. Designed to reveal inconsistent timing of the spark, which is a common cause of ignition-related performance issues. Features and attributes Heavy-duty construction built from durable, high-quality materials for reliable use in workshop and field conditions. Works on standard spark plug connections to test ignition performance without removing the plug from the engine. Compact, handheld size for easy maneuvering in tight engine bays and comfortable single-handed use. Clear visual indication of spark activity across the electrode gap for immediate, unambiguous results. Performance and compatibility Suitable for diagnosing spark and ignition issues on engines that use spark plug connections. Effective for detecting intermittent timing inconsistencies that manifest as engine misfires, stumbling, or loss of power. Robust construction and reliable electrical contact ensure repeatable, trustworthy results during routine troubleshooting. Practical use scenarios Rapid pre-installation check: confirm a new or rebuilt spark plug is firing correctly before fitting it to the engine. On-vehicle troubleshooting: connect the tester to a suspect ignition lead to determine if a misfire is caused by the plug, the lead, or another ignition component. Small-engine maintenance: verify spark on lawn and garden equipment or other small engines to pinpoint ignition faults quickly. Tone and reliability Professional, no-nonsense tool intended for mechanics and DIY users who need a clear, direct way to diagnose spark-related ignition problems. Built to offer dependable visual diagnosis so you can decide quickly whether to replace a spark plug or continue investigating other ignition components.