I have experinced some strange things coming in to corners also. So I put up a videocamera and did the same corner over and over again. The thing I noticed was that when coming in to the corner and braking you normaly have the clutch pulled in. Just before you enter the corner you normaly release the clutch. That´s when the engine braking comes into play...and suddenly the rearwheel slides slightly to the side, making the front wheel loose grip and may feel like and oversteer.
So I think that some of the handling problems some feel with the 2010/2011 YZ450F has to do with the engine braking. I never experienced this with the Honda´s I´ve had before.
I don´t feel this is a problem because you get used to it and adapt your riding after it. No big deal if you ask me.
That's a good observation...
A lot of coaching goes into leaving the clutch out while braking - but these days with the big thumpers the risk of stalling is much higher than it used to be...and it's much more common to have the clutch in.
I noticed with lighter riders - the damn thing loves to go side to side in the back in fast braking bumps....not confidence inspiring. But its a neat bike with a unique engine character - feels fast and sounds fast - but not necessarily actually that poweful. It definately has a "hit" to it.