I'll buy one thats never raced? What is the best 4-stroke dirt bike? Suzuki RM-Z 250, Honda CRF250r, Yamaha YZ250f, or a Kawasaki KX250f? I'll probably be buying one around the years 2004 to about 2007, if that helps any. Which one runs longer without having to rebuild it, is easier and cheaper to put mods on, is best in the sand, which is faster and more durable, and of course which one is more bang for my buck? Please answer my questions, and Thank You to all who answer.