hi all my mate just bought a 92 wr 200 with a blown motor.The power valve screw come loose and passed through the motor totally screwing top end,piston rings and needs resleeving.I was wondering wat the difference is between yz and wr,will a yz 250 or 125 motor bolt in or will it fit in with minor mods to the engine mounts.Any ideas or coments would be appreciated.