http://www.webercarbsdirect.com/v/vspfi ... DGAVEV.pdf
If you follow the trail from the choke shaft to fast idle Lever (63), this is where the choke should raise the idle and its high idle set screw is (hidden behind the choke housing). If the choke mechanism isn't raising the idle, but it is closing the throat, then there's a problem behind the choke mechanism itself inside the housing, before it moves the fast idle lever. There is also an adjusting screw on the side of the choke housing (56),which adjusts the choke pull off -vis a vis the choke position itself.
This shouldn't be rocket science, that's why you put it on in the first place.

Usually when I'm in a situation like this, it turns out to be something stupid like a missing cotter pin where I can't see it or some such junk.
weber carbs direct (see above) has a whole section devoted to the troubleshooting of each specific carb if you need it, complete with a choke section.