I'm rebuilding my carburetor in this thread, but I think this question needs its own thread. I don't know how to reinstall the 1945 with the gradient power enrichment system. I'm not even sure if it's moving as freely as it should. Here's what it looks like:

and a closeup:

There's a gizmo on the throttle shaft with a round tab that normally holds up the brass rod. But when the throttle is fully open, the throttle bracket rotates the gizmo, lowering the tab and allowing the rod to move down (a spring in the bowl cover pushes the rod). The upper end of the rod is an inverted U inside the bowl. When the rod comes down the end of the U catches the power enrichment valve to mechanically force it open.

I have two questions. First, shouldn't the tab gizmo turn freely on the throttle shaft? It seems to be slightly jammed between the throttle body and the bracket that the throttle cable connects to (sorry I don't know the terminology better). Second, how should the little spring be oriented and what are its ends supposed to catch on? I think the little spring is to make the gizmo push the rod back up when the throttle is closed, but I can't see any way to make it work.

I think I figured it out.

First I straightened out the spring gizmo. That entailed removing the throttle plate and shaft. The throttle plate screws came out without too much trouble. I used a screwdriver to hold the accelerator pump cam and spring together while it was off, then I used pliers to straighten the gizmo so it turns freely on the shaft without fouling on the neighboring stuff. I also filed down a couple of burrs on the throttle body edge. Putting everything back together, I used a tiny dab of red Loctite on the throttle plate screws and the nut at the end of the shaft.

Then I figured out the long end of the spring must tuck behind the fast-idle cam next to the idle stop screw. Here's the view from the right side:

and from the left:


Of course the spring has to be put there before the throttle body is attached to the carburetor. The only way I was able to hold the spring while attaching the throttle body was to put the carburetor upside-down in a vise so I could use one hand to hold the throttle open and the other to hold the spring in place. Without the vise there was no way to do all that while also holding the throttle body gasket in place.

Anyway, now all seems to be working as it should. When you open the throttle all the way, the power enrichment rod is allowed to lower, and when the throttle closes the rod is pushed back up. It occurs to me that without the spring in place, the rod could stay down all the time, leaving the carburetor enriched any time there is low vacuum, as opposed to only when the throttle is more than 80% open.