Re: Carb issues
So opening and closing the throttle doesn't change the engine speed? The throttle slide has got to be stuck, or you have a giant air leak somewhere, probably the top of the carb where the cap for the throttle slide goes on.
You need to take the air cleaner off and look inside the carb neck while you have someone open and close the throttle (engine off). If you don't see the throttle slide in there almost closing the carb with the throttle off, and moving up out of the way with the throttle on, the slide is stuck. Unscrew the top cap and pull it out. Make sure that when you put it back in that the notch on one side of the slide fits down to match the little pin sticking out of the side of the tube the slide fits in.