Thanks for the ideas. Sometimes you can't see the forest through the trees, and the community can hep one find the path.
Answers to some of the above questions:
Nope, didn't degree the cam. It's a stock grind from Norvil. Maybe I shudda..
Exhaust has no crossover, it's 750 style. Intake is stock and air filter is new.
Valve clearances set yesterday after a retorque of the head.
Haven't done a compression or leakdown test, but it sure feels sound at the kick lever (850 owners know what I mean).
My original carbs were sleeved about 10,000 miles ago. I had some issues with backfiring a couple years ago that prompted me to buy a new set off eBay and they ran great right out of the box. (That problem was bad valves). I have about 5000 miles on those. After fettling the left carb for this problem I put the original ones on again just to compare. No difference.
Both coils are new, as is the whole ignition wiring (converted to neg earth and switched the Boyer for a Tri-Spark). The only difference is that it doesn't stall at lights any more (way to go, tri-Spark!).
I'm gonna do a compression check tomorrow. I think I'll also replace the high tension wires, since those have not yet been changed and it's easy to do.
Dave from CT