With my limited knowledge and none of this sled, I would say that the basic design of these sleds is to have a 2 piece stator (coils under the flywheel) with one loop serving to work for the electrics (lights, etc) and one to serve for the sled ignition.
So it is possible that one loop went out on you while the ignition side is still working.
Check everything else of course first, but in the absense of the obvious, it could then be the stator.