I topped the tank off with regular no alcohol gas today, then went home and put my portable wide band O2 sensor on the bike. It still has a little of my av gas storage mix in it.
I only got a short ride, but it has a strong exhaust pulse through the probe that I made and reads mostly on the performance side between 10-1 at richest and 12-1, the only time I saw 14-1 was with a closed throttle. I'll get a pic or two, maybe a video while under way if I can locate the phone camera safely. With an extension I might be able to sample individual cylinders, the Kerker muffler is pretty wide open inside. If the probe is 3/8" OD I could use a piece of aluminum or copper tube attached with a compression fitting.
I think the #4 carb has a low slide, I've cleaned and checked the jets but the old fuel line (after a clean filter) did have some crud in it. Hardly any vacuum at the air filter when idling.