Ok I have read post for three days! Eyeballs are going to fall out of my head. I have a bottom end bog that I cant get rid of. I ride at St, Anthonys sand dunes (5000 Ft, about) I have a mild dune port, Milled .040 head (19cc domes) t5 pipes. VF3's and cages. lightend flywheel. stock carbs k&n pods. 310 mains 27.5 idle. I think i'm out 1 turn fuel/air. I run 110 oct fuel. +5 woodruff key (installing an adjustable timming plate this weekend). Also crank is welded and trued. Aftermarket crank berings and heavy clutch springs. As soon as it comes off the pipe even a little it just quits pulling. Any help or ideas? Thank you in advance!!