it's your c.d.i...change the c.d.i out with one from the same year and make..this is a common problem that your telling us..i've seen it alot..change out the c.d.i...this will fix your problem...oh..and welcome to the forums.Folks,
I am working on a Fourtrax for my brother in law that just quit running. What I have found is in the coil I think. I get a spark when I first hit the starter. With the motor turning over full tilt, there is no spark. Let go of starter button and I will get some (not much) spark as the motor quits turning over. Is this a bad coil or something more serious?