Had a chance to see this carburetor. The extra hole my friend is trying to describe is in the wall of the carburetor barrel itself. If you were looking at it from the bottom with the throttle closed, the extra hole can be seen with the spray bar visible. I can only imagine that the purpose of this is to enrich the mid-range. So.........was this a carburetor possibly for a helicopter engine or jet or whatever? Don't have a digital camera but will try to get a friend to snap a picture and post for me. Thanks for the help. Rick