shd3920, this belongs in another forum. But in short you need three things to get it running. Is it getting fuel, is the glowplug glowing, and do you have compression? Maybe I should include a fourth, a good spin of the prop. If you check those first three, you should be starting. Let me add, if you have too much fuel (flooded), that will give you problem starts, cold weather will diminish the effectiveness of your batteries, and if your backplate/head are loose or the gasket not good, that will give you problems. When I have a balky engine, I start checking things. Oh and one safety concern, keep all wires and hands and fingers away from the possibility of an engine firing up unexpectedly. Especially if you use a filter or power panel.