Are you keeping your air filter clean and not riding it right away after installing a fresh one? And one that is not over-oiled? I would try turning your fuel in(leaner) at quarter turn intervals and see if you get a bit more response off idle. Since you already know that it is set at 2 turns out, you can always go back if you don't like how the engine responds running a bit leaner down low. I have mine set to where I get a little muffled exhaust pop when the throttle is chopped and this gives me instantaneous response.