2013 YZ 250 f is it the rev limiter?

I bought this 13 250f before Christmas but haven't ridden it much. It's the first 250 f I've ever ridden, finally got a chance to let her rip on a flowing track. It breaks up and sounds like a bike with ignition troubles or a drain pipe sized main jet when I'm on the gas hard.
I'm not a 4 stroke guy, have about 12 hours on my 450,, I've never had it do this but I'm a short shifter on that thing, Not game to wring its neck...but this 250 f, I'm trying to ride it the same as my 125.
It has a DRD slip on muffler and stock jetting other than a #50 leak jet I put in to eliminate that lean bog when you snap the throttle on...
I've heard fuell injected YZ 250f's making a similar noise, but figured it came from someone messing with the mapping or something.
Is it the rev limiter? I didn't really think I was revving it that hard...
Anyway , if anyone that has experience with carbureted yz 250 f' could have a bit of a look at this 5 min video and let me know what you think.
Video is unedited, there are 3 of us riding, a cr250 2 stroke Honda, a Husky 4 stroke and me on the white 250f in the red and black riding gear.
You can hear the thing plain as day..
Am I just over revving it , or do you think there's a problem?
Thanks in advance