Curious if you found the cure.
I had an old VW beetle. When I bought the car, I got about 3 miles down the road before the engine started to loose power... and then shut off. I couldn't get it to start, so I towed it home.
I found the cause was the previous owner improperly adjusted the valves. All of the rockers were set to zero lash. Started and ran great. Then when the engine warmed up, the valves would not seat as there was no room for expansion... compression lost... engine stalled. I readjusted the valves and that sucker ran like a dream to the day I parked it.
Just a thought.
98 KLR650, 99 Fat Boy, 07 GZ250, 04 V Star 650 Classic