When im maintaining a steady throttle between 4k and 6k rpm, anywhere at 4th gear+, it almost always starts to act as if it is running outta gas.

UNLESS im behind another car. but I have to almost tailgate if im at 70mph and I really dont like to tailgate on a motorcycle lol

Is this a matter of cleaning carbs? adjusting anything on carbs? any sensors?

Any help is apreciated.