RE: Dirt Bike revs uncontrollably when started
Yes. Take the carb off and fully apart. CLean and inspect it. Also check the carb boot for cracks on the engine side. Also check (if applicable) the reed cage boot. Anything from the carb to the engine should be sealed tight. It does sound lean to me. Also check to see where the clip is on the slide. If you take the top of the carb off (unscrew it) and pull the slide out there should be a E clip holding the needle in the center on. It will be at the top near the cap. Check to see if it is in the center, top or bottom position.
Kevin