2012 RXP X Losing Power at the top end

[RXP X 260]

Hi everyone, I have a 2012 RXP X 260 that has suddenly become 3-5 mph slower. Earlier this season it was no problem to get 8k-8.2k rpm and 65-68 mph, but now I'm topping out at 7.6k-7.8k and 60-63mph. I checked the impeller and wear ring, they are in great shape . I also had the dealer hook up the computer and he said there weren't any error codes. Engine bay looks imacculate, and the supercharger seems to be working normally. It is almost like it is hitting an electronic limiter (and no, I'm not using the learning key). I ran a fresh tank of 93 octane through it with a can of sea foam, and bought it from a different gas station from what I normally use. 3 tanks later it is still doing it. I've also noticed that the exhaust note has changed. In the mid range rpm it used to really roar when I was flushing the machine after riding, but now it just maintains a pretty consistent exhaust note throughout the RPM range. Any suggestions? Thanks !

 

[RXP X 260]

Finally changed the oil and spark plugs, seems to have remidied the top end problem. Only thing that tripped me up was the amount of oil to put back into the engine. All of the guides I found said to replace with the same quantity of oil you remove, but my removal vessel didn't have a quantity indication on it, so I just went to the manual which said the capacity for the engine was 3.2 qt's. I added that, ran it for a minute and a half, then idled for 30 seconds, shutdown and checked after a minute...the oil wasn't even registering on the dip stick. Ended up putting in a hair over 4 quarts to get to a normal oil level indication. Did a test run and was able to get to top speed again.