I bought this 2004 kx 500 from a privite party. The guy tells me he's did some adjustments to the carb. Because it was running too rich. Really dont know what he's all did and cant locate him to ask. He told me the bike has LESS then 11 hours on it. I can believe him on that one, cause you could put it up to a brand new one and never know the difference. But back to my Questions now that you know alittle about my bike. It seems to me, my bike is running lean at mid to top end as when i let off the thottle my bike still revs alot and chugs bad and pings. Someone told me i might have a bad seal in it sucking air but i thought to myself it's too new for this to happen. So, i'm asking you guys. Could it be? Could anyone tell me all the correct jets sizes that a bike come with, from the factory? i dont know what he's all changed. Right now, my main jet is 168, my slow jet is 55, my needle is n82n i think?... the clip is in the middle and the air jet is turned out 1 and a half out. and i dont know what my slide is. My elevation here is around 2000. and temp is around 70 here. Anyways, if anyone can give me any advise or a starting point i'd be really thankful.