Did you see the issue it is having? Basically, breaking up at 2500 or so and the scope shows the ignition is fine. Just started this year he had pump gas in it no stable. Really thinking power valve. Carbs were pro rebuilt a few years ago no real time on them. Any ideas what to check? When he stomps on it and the outboards open it runs great.
Yeah I would suspect something wrong probably with the center carburetor. But you know me I would just take it off take it all apart and find out what's wrong with it. Could be the power valve though