The PV is interesting.
Just a mod for easy changing of spring pre-load / perhaps spring weight, and a damper / adjustment of the air pressure related to the std PV, Or a different power valve entirely? I'm not that familiar with the 'look' of a std YZ 250 Cylinder, to instantly know of any differences with this ESR cylinder casting.
I'd love to know.
At that price, it puts it at the level of a 300 KTM OEM kit . Seems quite a deal, to me, especially as it retains a power valve, when many big bore kits have, previously, done away with PVs. Steel liner / plated liner - either has it's merits / demerits.
I dearly like to have an adjustable power valve on my 500 - and I intend, one day to fit one to it. My experience with pressure actuated PVs, on my Maicos, years ago, was great, especially after I made an alloy top plate, with pre-load adjustment and tried out various springs. The only problems I had, was with the diaphragms, when I went a bit too far with things. Simple, easy to make PVs. On the CR, I probably would have to raise the cradle tops / go to double down tubes on the frame, which is a simple thing to do. Though, I have given thought to using, say, 2 KTM 65 PVs, to widen the exhaust port, or give it adjustable outer 'eyebrows'. It's a way off, though.
