A couple of pics on the test engine. Again note I didn't have a correct choke pull-off in stock so I just capped off the vacuum port so I could run it.
There are two small tabs on the top casting that are meant to act as a closing stop for the secondary air doors. Unfortunately on this carb, one was broken off completely and the other was badly worn. Since the carb <span style="text-decoration: underline">must</span> have some means of preventing the secondary air doors from trying to close <span style="font-style: italic">too</span> far, I employed a common trick of using a small flat washer under one of the rear-most screws to act as a stop.
Ain't pretty but it works, and it saves an otherwise junk (and somewhat hard to find) casting from the scrap heap.
Click the pic below for the video. Please note the air/fuel readings aren't entirely accurate on the meter. The rings in my test engine are beyond shot, and as such it huffs a considerable amount of oil which skews the readings. (I really need to get that poor thing rebuilt, but I just can't find the time!)
FWIW, the ~12.5 a/f ratio on my meter directly correlated to a ~14-1 a/f ratio on Kammers dyno, so you can extrapolate from there.
Steve, I'll give you a shout next week as soon as I've got the pull-off in.
Thanks again for letting me be a part of the build.