2014 rzr 1000

Every once in awhile it will only rev to 7500, it seems like one cylinder is down on power or maybe both. Shut engine down re start and it runs normal.

Checked fuel tank there’s no plugged vent line, no codes on gauge .

Anyone have any idea? Dealer said not much they can do with out codes and if it’s not doing it when I drop it off.
Lately it’s been doing it roughly 3 times a ride.