the air screws adjust the amount of air that gets mixed into the pilot circuit. it pretty much controls the idle to off idle air mixutre. turning the screws out will lean out the mixutre, and turning them in will richen the mixture. what altitude are you at and what is your elevation? 230 mains sound too lean to me. what pilots you have in there now? you should need 27.5's w/pipes and no air box lid. also, try 1 to 1-1/2 turns out on the air screws, to see if that helps your starting issues. pilot circuit needs to be a little richer to help the starting problems, and turning the air screws in will do just that. also, going to a richer pilot jet will help too. how does the engine respond now, when you rev it up in neutral, and does it want to get real boggy on take off? you need to rev it up pretty good and feather the clutch to take off?