I fogged my 1986 Evinrude 90hp V4 today. When spraying fogging oil into the top carb, the engine would almost stall out. When fogging the bottom carb, the engine barely fluttered. The boat sat for 2 years before I bought it, so most of this year has been spent working on the boat rather than fishing from the boat (6 trips since July). The boat is winterized now, so I won’t worry about it until April, but how do I know whether to rebuild the carbs or simply replace them? The boat runs good now, but It started out with idle issues. I have the idle adjusted up because it absolutely hated running at low RPM. I always suspected dirty carbs, even though the spark plugs burn at the right color.
I’ve used fuel system cleaner and K-100 in it this year, and I am storing it with a full tank of ethanol free premium, marine Sta-bil, and Sea Foam that I ran through the engine before fogging it. The boat has a 24 gallon tank.
What factors determine when to replace rather than rebuild the carbs?