I have a 1982 Merc 50hp that I got a year or so ago. Last season the thing ran great. This year not so good. I went out today for the first time. It started good and ran good for about 20 minutes. Then, it slowed down and died. Now when I start it, it starts right up, it runs for 5 seconds then slows down, idles rough for a couple seconds and shuts down. Just before it stalls, it appears to be flooding itself with the gas that comes out of a small screw type valve at the top of one of the carburators. I tried turning the screw both ways but it will not stop the leaking fuel. What do you think about the idleing thing and the shutting down and the gas leak? Everything is tight and in place, I tried adjusting the idle mixture screw, that didn't help with the idle thing but if I richen up the mixture enough it will run a little longer but it misfires badly.
