A little background info here... I currently have an 09 CRF 450 that I love to ride but ultimately it has given me nothing but problems. As soon as I get it properly functioning again, it's gone. I'm considering the YZ 250 2-stroke or the 2010/2011 YZ 450. What can you guys tell me about your 2010's, good or bad? I race mainly off-road events—some desert, some gp style mx & some woods. How does the bike perform in these conditions? Also, I keep hearing something about the valve cover gasket leaking???