Thanks for the last note. I currently have the stock spacer between the carb and the manifold, which is made of a composite heat-resistant material, about 1/2" thick.
One other thing that I'm going to check into is that I'm getting a slight dripping of fuel around the outside surfaces of the lower butterfly shaft when I toggle the accelerator by hand. My suspicion is that the raw gas which the accelerator pump is discharging into carb throat is collecting on the interior section of the shaft and is then trickling past the bushings in the carb body to get to the outside of the carb. Given the comments above about flooding, I'm thinking this could be contributing to that. I'm also thinking this might be contributing to a vacuum leak. My '42 carb, which is slightly different for military applications, has rubber insulators on the shaft to prevent this type of vacuum leakage. I don't recall the civilian model having those, but if the coil doesn't turn out to be the culprit, I'm going to pull the carb to see what the fit is like on the butterfly shaft.
