Mine is the same way. Bought starter drive years ago that didn't solve the problem. the fork that engages starter drive wears and doesn't engage drive as deeply as it should. I have 6V starter for years running 12V. Now I have a new ring gear that I got from chevs of the 40's riding under seat. Read down and you will see I am switching to Hydramatic driveline if I can clear all obstacles and then I won't need the new gear. Guess I should choose one direction and stick with it huh?