Yes on air screw, lightly seat screw then open CCW. You young man have just learned part of the art of tuning, no two engines/set-ups are the same. You might need 1 3/4 turns 2nd clip, he might need 1 1/2 middle clip. You have to figure out what YOUR motor wants.
On another note I'm "cooking" a pipe right now, that electrolisis method works awsome. Hoping it will take all paint too. Been in about 24 hrs, might make new batch little stronger.