In the process of rehabing a artesian that is about 10 years old. I have replaced the controler, main pump w/3hp, it had a 2hp. I never owned it when was running before. Now I have the air regulator knob popping out like a rocket when the main pump is running. What could I be up against?

(Better late than never)
This is usually due to a clogged jet. That is, the internal entry to the jet body itself is clogged, and the water is being diverted to the air inlet instead. It should be going the other way.