Help! Newbie has a problem with 82 ATC 200... installed new carb and motor runs wide open. I've read every thread I can find and turned the slide every direction- lined it up with the 'spot' on outside of tube. It seems to bottom out; cap is touching threads when I install. Still have some throttle left too. No air leaks, good boot... I'm outta ideas.

 

It sounds like a throttle cable issue. Pull the carb loose, but keep the cap on. Look in the back of the intake and see if the slide is all the way down.