I have a couple of questions being a two stroke guy thinking of swithing to a four stroke. What is the major differences between the CRF and YZF motor and why does the CRF have so many issues? What about adjusting valves? I have heard that with the CRF you have to remove the cam to adjust the valves, is this true of the YZF and RMZ? I am really looking forward to the 2006 450 shootout!