you want the WR250F not the WR250R.. http://www.yamaha-motor.com/sport/products/modelspecs/66/0/specs.aspx
You would think that a WR250R and a WR250F would be more or less the same bike. That is not the case at all. The frame and engine are different as are the weights. How they got that street legal WR250 to be 300 pounds I'll never know. Crazy...
you're looking at the WR250R not the WR250F big difference between the two. an aluminum framed wr250f weighs about 260 pounds.