CR250 Cylinder swap??

[ERBE]

Has this been done?? Cant you run the power valve off of a Vacuum Diaphragm off of a water craft??

[2muchquad]

Im sure something could be done.I bet if you could find something to drive it from the intake or crankcase pulses it could work.Or have a spring loaded valve in the exhaust flange area that would open up at higher rpms once the spring tension was overcome and be more closed at lower throttle settings.Experimenting with spring set ups would be the hard part.i bet it could be done.Get a ski doo snowmobile powervalve set up and make your own;)

[cdrookie]

anything can be done, it just takes time and money. being that these 250r's were the dominate race machine for over a decade, and that practically everything has been tried on them/to them, there's probably a reason why this isn't mainstream.

[tt racer]

It cant be done its been tried for years. FTZ uses a cr cylinder with the power valve blocked off. The reason for using it is nicasil sleeve better cooling and better port wings on the 01 cylinder.

[mxduner]

the whole advantage of using a cr jug s for the power valve...and slightly to use nikasil. so why you would want to block it off is beyond me:confused:

[2muchquad]

the cr cylinders were used more or less for the modern port layout,the powervalves were blocked off,esr does the same thing with these motors for microsprints.Powerevalves are nice but acceptable lowend can be had with a good setup with good topend over rev.Thats the beauty of a 250r:)

[MossboysRacing]

What does it take to put a 01 cr250 cylinder on the 250r bottom end?

[2muchquad]

The cases have to be modified for the cylinder to drop in.The 86 to 91 cr cylinders will bolt on though.