first off ive spent 2 hours searching the threads for an answer to my problem with no results, i looked at the jetting database and not sure what to do. 2005 yz 450 168 main (165 is stock) all other jets stock fmf powercore and powerbomb header (only changed cause they were smashed to hell) temp. 60 to 80 the bike is extremely hard to start, need to turn idle screw almost all the way in to get it started. once warm and running good the throttle hangs like crazy. also the power band runs out faster than normal at higher speeds, runs pretty good at slow speeds, just hangs as i let off the throttle. ive played with the fuel screw and idle with no resolve. from what ive read im thinking of going to bigger pilot jet? any help would be greatly appreciated, im stuck and dont wanna make things worse. P.S. bought bike new and never had problems till i changed the exhaust.