What kind of carburetor are you running. I am trying to think of how to describe it but here it goes. The throttle arm on the carburetor has an arm that the throttle cable hooks to. Moving the throttle cable attachment closer to to the throttle shaft will shorten the stroke needed to open the throttle from closed to open. Moving it away from the throttle shaft will lengthen the distance needed to move the throttle from closed to open. You may be able to move your throttle attachment point on the carburetor closer to the throttle shaft and adjust your cable then.
