Ok the bike (2006) already has a header, pipe, high comp piston, jet kit jetted for 50/50 mix race gas with pump, ported and polished head, stock cams, I obsolutely love the bike and don't want to upgrade to the newer 250f because I dont think its worth the money seeing how I dont have any problems with the new 250's on the track. Now here is my dilemma I race 2 vet classes 25C and Open C and after this spring half I will be moving up to B, if I get a top 10 start I always finish top 3 bearing some crash offcourse but on ceratin tracks with long straights or sand starts I can't get good starts and 4to 5 laps never gives me enough time to get back to the front and ill crack the top 6 usually. I'm 6.1 and 185 lbs, is the 290 kit worth the bang for the buck or should I just throw in the towel and get a 450 like people have been telling me. I've been on 250F''s since they came out from yamaha and have grown so used to the bikes thats its hard to give up the light weight and rev happy riding. Sorry to be so long winded but guys with 290 kits, are they reliable, how long before rebuilds, is the power worth it. Thanks in advance.