Got a '04 YZ450F. Runs awesome but sometime the RPM's will hang like I'm choking it. I don't believe it's the throttle cause I twist it forward to make sure when it does it. The only way I've found to make it stop is (if I'm sitting) put it in gear and move it a little or (if I'm rolling) tap the kill switch just a little to make the engine stutter. But it only does it every now and again. Anyone got any ideas?