Metal in Motion - I wanted to show you guys how I diagnose an engine that has no spark to the spark plug. You need to determine if the problem is on the kill circuit which grounds the coil and turns the engine off, or is it the coil itself. Although this is on a push mower, the same method applies to riding mowers, pressure washers, go karts, generators, weedeaters, blowers, etc. They all use this same or similar design, and have a ground wire attached to the coil. When the on/off switch is turned off it grounds the wire going to the coil and the engine shuts down. KEEP YOUR FEET CLEAR OF THE MOWER BLADES WHEN TESTING!