cr250 cylinder

[Matt102]

I was just wondering if it was possible to put a cr250 power valve cylinder on a trx250r? Would you have to make any modifications?

[AndrewRRR]

ftz does the mod. www.ftzracing.com

[airheadedduner]

Unless you want a strictly top end motor it is not recomended. The CR has very agressive porting. The mechanical powervalve version will not make it a pv. You have to jam the pv open becuase the R bottom end has no way to drive it. The 89-91 CR cylinder will slide right over the R studs. The newer electronic pv would be the way to go. But, by the time you got all the electrics(cr ignition would probly be needed), and you have to move the studs on the bottom end farward an inch or so(though that may be the yz cylinder), it would have been cheaper to just buy a pv from duncan, lrd, esr, ect....:o The advantage to the CR cylinder is stock, it has a nikasil coating. I think if you where to buy an exhuast gas pv like most aftermarket companies offer they don't come with nikasil unless you ask for it, and you will pay for it too, big. I looked into it too. Not viable unless you wanted a drag, flat track, or STRICT dune bike.