I just bought a 1985 Mercury 60 ( 3 cyclinder) from a guy and put it on my pontoon boat. The motor runs great but seems to be a little rich on the low end. I work on two stroke motorcycles but haven't done a lot on boat motors. <br /><br />On a 2 stroke motorcycle the mixture screw is usually called an air screw. Turn it out (counter clock-wise) and it adds more air thus leaning the mixture. And vise-versa...turn it in and richen the mixture by not allowing as much air in.<br /><br />Does the mixture screw on this boat motor work in the same way? Someone told me it was the opposite, meaning that the mixture screw is a fuel screw and that turning it out would actually richen the mixture by allowing more fuel in.<br /><br />Can someone clear this up for me as I have not ordered a manual yet.<br /><br />By the way, the settings are now set at 2 3/4 turns out for the top carb. and 3 1/4 out for the bottom. That is the way it was when I got it.
