merc 3.0 running rich?

[beason]

I have the 4 cyl merc 3.0 in my boat and burned an entire 22 gal tank in about 9 hours of lake time. (not all running, but probably 80%). I can smell gas fumes at low speed, it idles rough, and if i dont let it idle for 5 seconds or more after throttling back to neutral before shutting it off, it will diesel, and knock.

Does this sound like a rich condition? If so, does anyone know how, or have documentation on how to adjust the carb? I downloaded the service manual for the boat, but I would like to have some personal experiences before diving in.

 

[chuckles]

check timming idle adjust screw or screws on base of carb.turn screw in will lean fuel ,turn out to riching