My 01 sporty 883 has sporadic rpm drops while cruising at steady speeds. One time it started popping and sputtering then died, it restated fine and ran fine after that. I got this bike in Nov 2014 with 7830 miles on it. it now has 10,000 miles on it No mods to bike

 

I had a similar issue with my '07 Sportster. Turned out to be a loose battery connection. Just loose enough that at highway speed it would vibrate and periodically interrupt the electrical. It's one simple thing you can check.