Most people don't know this but the engine stops in one of two places every time it stops, at least withing a few degrees of rotation, there are only a few teeth 180 degrees from each other that the bendix actually engages while cranking but it's the same set of teeth each time, I used to run into this on Seadoos a lot and we replaced a lot of ring gears before Seadoo figured out the spacing was off causing poor engagement, in our case it was adjustable somewhat by deleting gaskets which moved the starter in closer and the housing back farther, nothing like that is possible on anything else that I am aware of. On some Yamahas I have had the ring gear spin on I have removed the ring gear , flipped it over and reinstalled it on the flywheel then spot welded the ring gear to the flywheel to secure it.