Ok so i been playing with the jettin srock is 250 main i have a reed spacer lrd adjustable pipe fresh 89 motor an mild port work.. mainly clean up.. 260 sputters up top.. 290 sputtees worse 320 falls on its face... 260 no lid sputters slightly 250 sputters a lil.. 250 no lid runs like a rabbid raccoon!!!!!!! WTF??????