I futzed with the idle mixture... only to return it back to the original adjustment setting (number of detents from closed). So the jam nut was tightened down on the idle stop screw, without adjustment! Creepy!
Cracked the throttle open to a driving range rpm and started twisting the intermediate screw... only to return it back to the original adjustment setting (number of detents from closed). Creepy!
Working on a bell crank to connect the throttle linkage so I can drive it, then will see if the intermediate or high speed jets need additional adjustment. Have never had this happen before... this was too easy!