seeing that it's not oily, but kind of watery....can you smell any odor of fuel in it? you might be leaking fuel from the intake runner into the head/valve cover area. 12 ounces is good depending on the track and what your running. for me, i'm on a medium banked track, but it's big and we're wide open all the time with high speeds going through the corners, so we need the extra few ounces to get it up to the head....
also, you didn't say if you were down on power or if it was just smoke...it it light or like a mosquitoe fogger?