Spark Plug Tester — Heavy-Duty Handheld Diagnostic Tool Why you need this tool Quickly determine whether a spark plug or ignition component is causing engine hesitation, misfires, or power loss. Saves time and money by confirming whether the ignition system is at fault before replacing parts or taking the vehicle to a shop. Simple, direct visual check you can use at the roadside, in the garage, or during routine maintenance. Key benefits Diagnoses inconsistent spark timing and misfires by making the spark gap visible during operation. Identifies spark or ignition failures, faulty contact points, damaged ignition wires, and poor plug connections. Robust, heavy-duty construction built from high-quality materials for reliable, repeatable testing. Main features Function: Handheld tester that connects to the spark plug lead and lets you observe spark activity across the gap to verify ignition performance. Compatibility: Works with standard spark plug connections and most gasoline engines (cars, motorcycles, lawn equipment, small engines, generators). Check your ignition lead type before use. Size & portability: Compact, easy to carry and store — designed for quick checks without bulky equipment. Material & durability: Manufactured from durable, high-quality components to withstand workshop use and repeated testing. Performance: Provides an immediate visual indication of spark strength and timing consistency to help pinpoint ignition problems. Typical use scenarios Auto troubleshooting: Diagnose intermittent engine stumbling or loss of power while driving or during test runs on a workbench. Small engine maintenance: Check spark and ignition on lawn mowers, chainsaws, or portable generators before seasonal use. Motorcycle and power-sports service: Verify plug firing and cable integrity during routine inspections or after ignition work. How to use (basic) 1. Turn off the engine and attach the tester to the spark plug lead according to the tool’s connection method. 2. Re-start the engine briefly or crank as required and observe the spark across the tester’s gap. 3. A steady, consistent spark indicates a functioning ignition; weak, intermittent, or absent sparks indicate problems in the plug, wire, contact points, or ignition system. What this tool does not do It is a diagnostic aid for visual inspection and basic troubleshooting. For advanced electronic diagnostics or engine control issues, use a full diagnostic scanner or consult a technician. Reliable, simple, and built for practical use — this heavy-duty spark plug tester helps you isolate ignition faults fast so you can make confident repair decisions.