you dont have to ajust your low speed needle unless your car loads up while ilding and smokes alot only on the take off. if your engine idles nice and when you gas it it kinda bogs and the ilde gets low that means to much top end needle. get a temp gun. the bubbling in the carb is normal. you shouldnt put fuel on the filter just put filter oil on it from associated 2.50$ just clean your prefilter and reoil it, dont drench it . it only needs to catch the real fine stuff and not clog the airway. dont put it on your main filter.