The ground should be mounted to your engine.(a black wire probably on the crankcase somewhere) it will be the only wire just bolted to something metal. If that's not the problem check the stator,rotor,& ignition timing sensor. I'd say one of these are your problem.
ok jump the black and brown wire that comes from the stator this will by pass the kill and key if it starts then it your kill or key switch. not sure what year you have but just look at the main wire harness from the stator mine are brown and black let us know
Back when I initially played with snowmobiles, they had two coils. One lightingand one ignition. Are the newer machines, 1972 and younger set up the same way. If I get the answer to this question I certainly will be able to help fellow sledders with relavent problems.
I have a 99 sno pro. The lighting coil is all tied together in the stator. I made my own fly wheel puller. If you wanted I could email you a picture of it (preaty easy to make). Anyway if you get the stator out I am also having problems with my sled could you tell me what numbers and letters are stamped into it, I think someone may have put the wrong stator in my sled. I have 2 stators same wiring but both have different #'s stamped in them.
i have a jag 440. it did the same thing. i came to find out that one of the wires that went to the bottom of the coil was only holding on by one strand of copper. so there wasn't enough juice goin to it. i soldiered it back on and it works fine. maybe that will help