Still having air leak where carb slides onto small intake pipe with my 80 cc 2 stroke Raw motor unit. Sanded pipe and will slide completing into carb and seats firmly onto o-ring. Clamp tightens down securely. Yet still drawing air there while testing with carb cleaner spray with engine throttle up. What else can be done there ? Now thinking carb defective - maybe crack in housing mold I can see. Any help will be appreciated.