Those idle/ air screws your talking about are they toward the rear of the carbys if they are then they are not idle screws they are air screws and need to be set at 1.5 to 2 turns out from a lightly seated position, your idle screws are located on top of the throttle override system slightly angled back. try 27.5 pilots, 260 mains & needle clip in third groove from the top as long as your carbys are syncronised properly this should be a fairly good setup for you to start with IMO.