Originally Posted by Gryphon12
But I need a DS, not a race bike. (My total solution would be a WR450R if Yamaha would ever make one.)
Gryphon, great post overall but there is no way Yamaha can make a WR450R. People keep forgetting that the WR250R is one cylinder from a four-cylinder Yamaha street bike, and actually detuned from its parent engine. That's why it's so reliable. The 450 is a purpose built dirt bike and if Yamaha tried to turn that engine into something street legal, it would be either much heavier or much slower and probably both.
Yamaha could make a WR450R from a clean sheet of paper, but it would not compete with a KTM for weight or engine performance. If you're just looking for a bigger, heavier, more powerful WR250R, that's a possibility.