Brett,
How did the carbs look when you took them apart?
Here's the latest. I swapped out the plugs and man, did that help a lot. It was crazy how just doing that helped it. It was running strong with no sputtering however I had to keep feathering the throttle to keep an idle. I rode it over to my mechanic's and we tried dialing it in. We got it idling albeit a little high. There was a slight leak coming from the banjo fitting on the carb. Here's where it got weird. We cranked the air/fuel mixture all the way shut (no fuel) and it ran fine. That told us there was something wrong inside the carb itself.
Friday I took just to see if it would pass emissions. It didn't but only on the sitting idle part. Friday night I rebuilt the carb. For starters it was missing the inner sleeve for the spring on the air valve. Then it had the wrong clip on the needle along with a twisted piece of wire as an attempt to keep it centered. Clean and put back together with fresh parts and gaskets back on the bike it went.
Long story short it ran about the same as before including with mixture shut off. I delivered it to my mechanic's and he noticed a number of things wrong including:
Float bowl a little high.
Some warpage from someone over-tightening the bowl.
Some warpage from someone over-tightening the banjo bolt.
Wrong jet size (too big)
Someone had increased the size of the pilot jet pressed into the body.
All this explains why it was running so rich and with the fuel off.
Fortunately the 1968 carb bodies were converted over from 2-stroke off-rode carbs so there's a spot to add another jet in the circuit. The plan's to add a new jet and close out the old circuit, fix the bowl, decrease the jet size and file down the carb halves and banjo bolt fix the warpage.
I'm supposed to pick it up tomorrow so I'll let you know how it goes.