It just sounds like it may be set too rich, to me; if not the HS needle, then maybe the LS. Try leaning it in to a nice flying setting and see if it improves; it's ready to go now, anyway. I never noticed any difference in the way mine ran from right out of the box till after two years flying; it's run great from day one. And the low speed needle on mine has never been reset from the original factory adjustment.