Malow, I first suspect the switch itself. I’m guessing that when you rotate the switch it loses contact inside it. Those switches are ususally pretty simple and very cheap at the parts store. They make an universal switch for lawn movers, boats, golf carts etc. You might try pulling the switch loose from the dash board. If the wires are attached to terminals where you can get to them there should only be three, turn the key on and short the starter wire to the primary wire to see if it will start. Other wise go down to your local parts store get a switch that looks similar to yours and try it. Wish I was there I would be happy to help!!!