It’s done!
The idle/pilot circuit needs adjustment. The bike bogs a little bit off idle and first gear. Once the motor feeds from the mid-range and above, it runs smooth with no hiccups. It goes through all five up and down, no problem.
What most likely happened is the tank let loose some gunk and goop that was stuck in there since deep cleaning the interior. It’s a common problem after cleaning out rust and age. So it’s time to pull the carbs and re-clean the pilot air jet and run some B G Fuel Injection System Cleaner through it.
While I’m at it, the bike will get an inline fuel filter to catch any more gunk and goop. There’s not a lot of room for a filter but I’ll try this one. It’s glass so I can see the fuel and the junk. It’s also got nylon mesh rather than paper that can disintegrate and cause more problems than it fixes.
Anyhow, that’s about the end of my 850 project. When I have the low end of the carbs straightened out, I’ll enjoy the ride before winter sets in…and see what happens in the spring!