Powervalve issue?

[SpeedyManiac]

Hi guys,
We're having an issue with a 2011 EC250 (my girlfriend's bike). When we picked it up in March, the bike ran great. It pulled strong from the bottom all the way to pinned. All was well, but now the bike is really soft on the bottom then hits very hard in the midrange and pulls well through to revved out. At first I thought it was jetting, but after playing with that it seems to be lying somewhere else. A few people have suggested I check that the powervalve isn't stuck open, so I did.

The powervalve isn't stuck open and seems to operate okay. I did notice that when I had the idle turned up and the choke on, the powervalve mechanism flutters (actuating plate behind the right side cover rotates approximately 60 degrees clockwise). Once the bike was warmed up, the powervalve remains shut at idle but as soon as I twist the throttle, it opens about halfway, then at maybe 1/3 throttle the powervalve is all the way open.

To me, it looks like the powervalve is opening too soon. Any idea what RPM it should be opening and how fast it should open up?