I have a 2003 CR125 and I bought it brand new. The last time I went to the track I had an issue keeping the bike running. If the bike went dead it would take a while to start up again. I took the carburetor off and it look fairly clean. The only thing I could think of was maybe the gas was bad or old. I have since drained the tank and I will try it tomorrow, but maybe someone can give me a little insight of what the problem could be. I will put a new plug in it also. Let me know what you think.