(It is a hat with 2 big butterflies and after I get it adjusted then I need to work on a problem about the gas pedal being so hard to press down. With it not running the pedal can be pressed with one finger, with it running you gave to kick it with your heel just to get it going.)
This helps,
you should have a wide open and a closed throttle stop independent of the barrel valve and you need to set the idle throttle stop, with a .005 feeler gage between the butterflys and the injection opening to keep the butterflys from from locking up when closed, also set the WOT stop to keep it from going over center when open. i set all the butterflys on a stacks with a .002 feeler gage. on my blown alky engine i set the idle stop with a .005 feeler gage and it's a 3 hole buzzard catcher.
You may be closing off all the air except what can be comming in through shaft bores to the engine, this would definately make it idle too rich.
Just my opinion
Zip.