Your main sounds small. Might want to up it if you are running long distances or in real deep sand.
I have the same pilot as you, i think 1.5 turns out on the air screws. Mine is a little rich though.
Sync your carbs and set your idle and you can fine tune your airscrews from there.
I would say you get to 3/4 ~ 1/2 turn out, go to the next size up.
Past 2.5 turns out, go the next size down.