Likely just a broken or corroded wire on the switch or bad switch contact. I'm not familiar with your setup but go back to basics check for power before and after the switch if you can. I will need more info to help more.
Thanks Hottoddie this is the best I've read for content. The only other questions I'm reading is about the oil holes in the crank and the piston needing to be turned 180 deg. Neither make sense to me?