In Reply to: 9N engine goes from idle to high rpm quickly posted by Mark on February 12, 2018 at 20:28:33:
It may help to watch carefully how all of the throttle and governor linkage moves when the throttle lever is moved. The problem may become instantly obvious. If that fails to reveal the problem, there are photos in the manuals Tim listed that will show how everything is supposed to be hooked up. Many things could be bent, broken, hung-up, or fouled-up in the throttle/governor linkage.