Maybe what you are seeing @ 10X is gas additives as previously mentioned. ?? Maybe.. ??
Interesting about your 'touchy' low speed adjustment.
Wonder if you are leaking air at the carb adjustment/s ?
Just a thought.........
Sounds like you have a thorough course of checking it ALL.
Please let us know when you find what spoiled your ride that day.....
The beading leaves a nice looking finish. & Some builders do the entire cases & then Glyptol them.
I won't use blasting on any internals. I'd rather Parts wash them. & use some elbow grease on them.
They have these Ultra-sonic parts washers supposed to be great & $$$ Out of my league. I have a friend who put his cases in the Dishwasher when the lil' woman was out. They came out Nice.. I don't think I'll eat over there for a while, though...