[Flash214]

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. 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.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.Can someone clear this up for me as I have not ordered a manual yet.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.

[fishingdan]

The idle mixture screws adjust the fuel. So I guess they can be called fuel screws. In=leaner, Out = richer.

[Flash214]

Thanks, that is what I was hoping since it would explain the richness of the mixture. The screws seem to be backed way out at the current settings making it run rich on the low end.Is there a general area to start from with these carbs.? I usually use 1 1/4 to 1 1/2 turns out as a starting point but again this is on motorcycles where the mixture screw is an air screw.thanks for the help.