First off, I'm a two stroke guy, forgive me!! So I bought a crf250 on a whim, and cause it was a deal. It ran great last time out, but suddenly it will not idle. It runs great, starts easily, and high idle with it choked runs fine. But with the choke off, as soon as I let off the throttle it dies. Its frustrating as hell!! I'm not afraid to rip into the carb, but am looking for guidance before I do. Any input?