Office of Steam Forum for Model & Toy Steam Gas & Hot Air Engines

Thanks for the replies thus far. Did a little more experimentation. The ground wire is securely attached to the engine, so that's not the problem. I checked the resistance on the electrode running through the spark plug, and it's around 14 kohms, which is reasonable, so I don't think it's the spark plug. Not sure what the gap is supposed to be, but it appears reasonable. When I turn the engine over, I hear a very faint spark at top dead center, but then another faint-er spark about 1/3 of a revolution later (slightly before it reaches bottom. Should there be two sparks, separated by a third of a stroke?