I would go back and check your method of adjusting the governor, this manual might help you out. After you are sure that the governor is set properly, the next thing to check is your throttle control, is it opening and closing the throttle plate. If that is correct, start the engine and move the governor linkage to see it the speed increases and you have return pressure on the linkage.
https://drive.google.com/file/d/0B6NaqjIxWV1ySkZjTTA5TGltZEE/view