throttle cable problems

If you can't adjust it out, then the easiest way to fix this is probably to attach the cable to a point on the carburetor's throttle lever that is farther away from the pivot axis (throttle shaft). That way the linear travel of the cable will be longer from throttle-closed to throttle-open. If you're out of space at the end of the throttle lever, make an extension out of a short piece of 1/8" steel or aluminum, drilled at both ends. Attach one end to the hole in the throttle lever with a bolt and nylon-insert locknut, and attach the throttle cable to the hole in the other end. This will also give you some adjustability; by loosening the locknut and rotating the extension, you can fine-tune the effective distance from the pivot axis to the throttle cable.