SparkCheck’r safely and accurately tests for proper spark, shorted/fouled plugs and even broken plug wires. This highly accurate diagnostic tool uses micro-circuit technology to help determine why the engine won’t start. Hands-free operation – just clip it on and crank it over. Works on all two- and four-stroke engines, with and without electronic CD ignitions. Ideal for all outdoor power equipment, vehicles, ATV's, snowmobiles, and more! Stores easily.