Update 4-27-17
I spent an afternoon tearing into my "new" carb. Either it's a mess, or my understanding of it is a mess.
As mentioned earlier, the bearings on the primary throttle and on the choke were all gummed up on arrival. I had them all un-gummed and was feeling pretty good about it, when I began to look at the linkage on the throttle side. This is when my afternoon got a whole lot more um.. interesting.
One spring in this mass of machinery does nothing. Two levers have no apparent purpose -- one is hooked from the throttle linkage to the secondary air valve to open it when the throttle is opened. On the carb in my truck, this valve seems to close when the throttle is opened. One lever has a pin in the side looks as if it is supposed to catch in a little hook on the throttle linkage so that the lever can engage the fast-idle cam. However, it doesn't catch in the little hook without manual intervention. The vacuum-powered choke breaker and the bimetal strip choke breaker seem to be redundant -- Based upon my analysis either should, on its own, open the choke and disengage the fast-idle cam.
Opening and closing the throttle does nothing to the fast idle cam or choke on either carb -- there's got to be a piece missing that does this, but I have no idea where it is or what it should look like.
I am fast running out of patience. Maybe I'll just invent and build a manual choke & fast idle setup, put it on this carb, and forget the automatic complications.
