Re: "newer" (late '90's) Johnson 3 hp wont start
Having to choke your motor to keep it running is usually a sign that there's a fuel delivery problem in the carb. I see a carb rebuild kit in your future. Kits can be ordered online or from your local Evinrude dealer. Soak carb parts (not plastic parts) in carb cleaner, blow ot all passages with compressed air. Install kit (gaskets, seals, etc) . Reinstall carb and set initial carb mixture settings.
BTW, the fuel tank is open ...right??