when i am riding a wheelie and it comes all the way back on me and stands on the grab bar it shuts off on me .....why?

 

because the gravity holds the fuel in the bottom of the float bowl where the jets can pick it up. Tipping the machine up on the rear rack causes the fuel to pour out of the float bowl, so the jets have no fuel. No fuel = no run.

 

weird. mine still runs on the grab bar most of the time.