HI everyone!! My name is rocco. I'm I new member of the forum. I bought a 1990 Kx250 back in early January as a basket case. Rebuilt the whole bike, and when I went to start it up for the first time, no spark. I traced it down to the ignition coil so I bought a cheap Chinese coil just to get it going. The ohms for the coil were within spec but still no spark. The coils on my stator were rewound, and the pulse coil's resistance is good, I have a pulse coming from it too. All the stator resistance's are good. So I traced it down to the cdi. Checked all my grounds, sanded them down. Checked all my connections with a test light. I bought a used cdi off ebay, put it on and still no spark. Does there have to be an engine to frame ground? Any recommendations or tips? Thanks, Rocco.

 

Usually both the input and output wires of the CDI have a black wire going to frame ground. The ground (engine and frame) is part of the electrical current path for the high voltage coil and for the spark plug.