Re: 1947-1951 3.3 evinrude sportwin troubles
That carb needs a deep clean, pull it off take it apart and soak all the metal components overnight in some carb cleaner. Blow the passages out with compressed air, reassemble and make sure the float is floating and the needle seat under it is seating correctly. If you have two screws/needles on the front of the motor, the larger one is the high-speed rich/lean adjustment and the smaller one is the idle rich/lead adjustment. When you put the clean carb back on there, turn both gently clockwise until they stop...don't force them beyond that. Back the smaller needle/screw out (counterclockwise) about 1 and one-quarter turn, back the larger needle out about 3/4 to 1 full turn. Crank it up, let it warm up and advance the throttle...as it gets its speed, turn the larger needle right or left, probably right (lean), until it hits it's groove and runs well at speed. Then throttle down and do the same with the smaller needle. It's best to do this initial tuning and the later fine tuning on the boat in the water, rather than in a barrel or test tank. Keep going...you're almost at the point of having a very reliable Evinrude for your outings.
