[Minnewaska]

Usually takes a few years for 'new-to-you' boat issues to settle down. Sorry for the trouble. My bet is on corroded wiring somewhere. However, rebuilt starters can have awfully short shelf lives too. Sometimes rebuilt just doesn't come out all that good.

 

[Minnewaska]

Victory snatched from the jaws of defeat! That's another common boat ownership repair saga.

I'm trying to picture this bolt, to understand why it won't fully seat. Makes little sense that the correct part would do that and require washers. At the least, get a lock washer. Perhaps it had one and was left off the rebuild. Maybe you just need the right bolt.

A tube of dielectric grease, to prevent future corrosion, sounds like it would be your friend too. Especially on the battery terminals.