Re: Carb weirness...
Running out of fuel in anything is not a good idea. There are suspended solids in even a clean tank and fuel mix and when you pull the last of the fuel out of the tank you get a concentration of that crud. I'd bet that the fuel petcock/filter/ needle valve might have been partially clogged then it washed through. Just to be on the safe side I'd pull the float bowl off and check and clean it before your next long ride. Just my thoughts.
Age and Treachery Will Always Triumph
Over Youth and Skill & "Charlie Don't Ride"