Disconnect the kickdown linkage. Check to see if the carburetor is opening all the way with the accelerator floored. Once that is confirmed, use your hand to push the throttle all the way open (helps to remove the return spring). Push the kickdown linkage all the way back. Then see if the kickdown linkage hooks up with the rear of its slot against the carb linkage. If not, adjust it until it does. Once it does, you now have full throttle travel and full kickdown travel.