I'm not sure what to do? I have a 93 CBR 600F2 with 29,000 miles, jet kit, Vance Hines full exhaust, sproket (top end), K&N filters. Before this moment my top speed was 162mph. I figured I would get a full tune-up, plugs, carbs sync., oil changed, k&n air filter cleaned, k&n oil filter. After 3 weeks of waiting I received my bike back from a supposedly good sportbike shop. As of now my bike will only do 142-145mph. The mechanic is trying to tell me, that I have alot of miles and its a old bike. I'm about to put my foot in his - - -.... What can I do to get my bike back to par? The bike always sounds like its running out of gas, (bogging down sound). Do you think he messed up my jet kit, or is it the carbs? please help. I have the need for speed.