The carbs could need to being cleaned -- you can easily pull the carbs because you have those individual pod filters.
While not rejetting for the pods will cause a problem (running too lean, overheating, etc) the symptom you have seems to very reliably occur at a certain rpm.
1) You'll need to get the specs for the stock carbs. Find out what the stock jet sizes are for the main jet, needle jet, pilot jet.
2) pull the carbs and using a magnifying glass, read the small numbers engraved on the jets.
3) compare those to what you found are the stock jet sizes for your bike.
I've had that problem when I was re-jetting carbs. I put the wrong main jets in (too big) and when I opened the throttle it was flooding the cylinders with too much gas and killing the motor. When I backed off the throttle the plugs were still wet and sometimes the bike would die.
So that leads us to.......
4) PULL YOUR SPARK PLUGS FIRST, before you do anything above. If they are black and sooty, my suspicion might be correct, that someone along the ownership line of your bike tried to rejet for the pods, put in main jets that are too big and when you start opening the throttle and getting up into the higher revs, you're fouling the plugs. Maybe prior owner tried rejetting, ran into the symptom you're having, and gave up and the wrong jets are still in there. As was mentioned above, re-jetting is not so easy -- it's very possible someone put in big main jets for the pod filters, and gave up in disgust when it didn't work the first time (then sold the bike to get rid of the problem).
5) If the plugs look fine: CHECK YOUR BATTERY. It needs to read 12.55 to 12.65 volts. If it doesn't, charge it until it reads 12.55 to 12.65 volts, but wait 1 hour after you've removed it from the charger. If you read the battery right after taking it off the charger it will read high, then settle down a bit lower.
Those 2 REALLY EASY things -- pull and check your plugs (black? carbs jetted too rich) and check your battery tell you a lot about the health of the bike.
After those 2 things seem okay (plugs not fouled, battery okay) pull and clean your carbs and check the jet sizes against the stock jet sizes. Pulling the carbs is more time-consuming than checking your battery and pulling your plugs so do the easy stuff first.
EDIT: if the plugs are not black and sooty, but are instead whitish and hot-looking and very clean (not black at all), you may be suffering from 'lean-lurch' -- the engine is losing power due to an overly lean air/fuel mixture (too much air flow due to the pod filters).
If you're getting a 'surging'or 'lurching' motion of your bike at those higher revs, and you have whitish, hot and clean plugs -- that indicates you're running too lean, which is altogether possible if my 'prior-owner-tried-to-rejet' guess is wrong. If the plugs are whitish, hot-looking, very clean -- you probably have the stock jets and you're flowing WAY too much air. You'll need to buy a stock airbox on ebay (easiest fix) or install bigger main jets and maybe adjust the needle clips too.
