what are the magnetic switches for on the side of my carb,1992 ext special

SORRY

It shuts down the motor if the throttle sticks wide open on you

Is that only for startup?? Or when running as well?

thanks I bought this sled blown up (lean meltdown) and both switches are disconnected and I didn't know if they could have caused the lean condition

NO

The throttle saftey system has been problem for some if not adjusted correctly. Its quite common to have them diconected or jumped at the carbs or the flipper to avoid the hassle