I have a Yamaha 250 OX66 that is doing this exact same thing. What was the problem with this one?
Thanks!
Don't know about Yamahas but years ago I ran into a couple Evinrudes that did this. The problem was with the power pack. They would heat up after running a while and electronic components would quit working. After cooling off it would run again until it heat up. New power packs fixed the problem. Whoops, I see I mentioned this about 5 years ago. Sorry about that.
Fair Winds and Following Seas
Bill H. PTC USN Ret
Chesapeake, Va
Not sure if Yamaha has one on my Opti I was experiencing similar symptoms turned out to be the main power relay. Took 3 years before I figured it out when it finally would not start so intermittent the dealer had no luck finding it. Check all your neutral start switches.
Zman
Did you ever find out the issue?