I have a 1998 YZ 125 and whenever I ride it takes a while to start up. So I pull the choke and kick it over and it starts but you have to leave it up for a couple of minutes while it warms or it will stall. After it warms you have to keep reving it to keep it running. When you start going it runs perfect no probelm at all...thats until you let off the throttle and it starts to bog down like it wants to stall. My uncle said it is something to do with the carb. Any HELP that you can provide is greatly appreciated.