Since it is a carbed engine, I would pull ’em off, clean the bowls, and check the fuel line. If it is getting old, it will start to flake off inside and that can be a royal pain. Family member has a Johnson 88spl, and I’d bet I cleaned the carbs 10 times one summer. I finally replaced all the fuel line and the problem went away, where he thought he was just getting trash in the fuel or had some sort of contamination in the tank…
The rubber tubing is not very expensive, and can be had at good auto parts stores… And even if it isn’t the problem, it may well be one day so you are one step ahead.

