Mystery cutting out in Argentina.2001 Heritage

[Miss POTATO]

Set up. riding 10,000 mile trip from Ushuaia,Ar to Oklahoma.
On the 8th day...1500 miles...everything working perfectly. On the warmest day in the trip, 85F, after sitting in direct sun during lunch, it started perfectly...then proceeded to cut out, spit, pop and generally refuse to go above 1400 RPM. After trucking it to the next town....and trying to start it...violle....works great.
OK, now when will this happen again and why?

 

[ultra...good]

First place to start; How long have you owned the bike? If for a long time, has this ever happened before and if yes, under what circumstances?
What kind of mod to the bike?
Did this happen right after filling up with gas?