You are running rich. You see a lot of souped up cars that smoke when you get on it. Getting the carb in tune is a never ending process sometimes. My Holley is causing the same problem. It is the carb the engine was dyno'd on and I am sure they tuned it for maximum power, but that has little to do with every day driving. I turned the mixture screws in 4 turns and still run rich. I have to check the jets and I am sure the venturis are too big. As for me, I will live with it because I plan more changes this winter and that carb is going away.
Question: with your timing at 42 degrees, which seems high to me, are you getting pinging or knocking? Are you running pump gas or racing fuel?
