At my wits end with this 2GC....

Progress! I took the newer carb off and checked out the lower housing. The new carb is a little bit larger all around but the throttle openings matched. Unfortunately I couldn't swap the throttle shafts because the old working shaft is too short to fit into the wider housing of the "new" one. I pulled the lower mounting plate off both of them and they compared pretty well.


You can see on the newer one on the right the venturis connect with the exhaust heat riser side. I guess this is some kind of EGR thing? Anyway, I swapped the lower housing from the old one to the new one and it's damn near a perfect fit. The idle speed screw barely misses and rubs on the stopper area on the choke cam. Other than that everything is fine. I was able to wedge it in about right and get to testing.

At first it would barely run and miss terribly. Garage full of smoke, eyes burning, pretty terrible. I cranked the idle mix almost completely in before it leveled out a bit and sped WAY up. I backed off the idle and got the tune in about right. The idle mix screws are WAY leaner with this new setup. The gas smell is almost gone now too! Idle is solid at 600RPM, revs like it should, and doesn't putter out. I'm reasonably happy here! I ran out of time tonight but tomorrow I'll get the idle speed screw working and a few little odds and ends fixed. Should be ready for a road test .

 

Idle speed screw fixed and road test completed. Here's the screw barely contacting the choke cam.


I added a thin nut and some thread lock to keep it from backing off. Works a treat and Franken-carb complete.