I've got a 400 ex that I had issues with my neutral switch (wire kept popping off the plug at the bottom).
The two things that I knew for sure it was a neutral switch issues is that
A: the neutral light never came on and the whole atv acted electrically "DEAD"
B: I could push start it and it would run fine.
I'm not sure about your rancher, but the wire I kept either kicking off or hitting with corn stalks was at the bottom of my crank (cultivated fields love to shoot SPEARS of friggen old stalks into the bottom of your motor).
The wire by the shifter marked "Neurtal Switch" is what I was kicking/removing somehow.
Again, I have NO idea if it's anything like your rancher. Someone else probably knows much better then me. But your symptoms sound just like mine, and that's what it was.