Any of you ever seen this cylinder before?

[rayman375]

Searching on ebay and came across this PV cylinder and never seen one like it before. It's item number 260777237617

[250Renvy]

It's not a working powervalve. It's just a CR250 cylinder with the powervalve blocked off.

A couple companies used to do that mod.

[rayman375]

Ahh, ok thanks. Why would they do that?

[etccb]

Back in the late 80's that was the way to go for a while. ESR also built a lot of those back then. It is just a 88 to 89ish era cr250 cyl with custom plugs made to replace the power vavles. The plugs could be changed to change the ex port. The power vaves on the cr were driven from down in the case and when installed on a trx bottom end this is what was done. They had a better port setup at that time. There were only 3 that were installed with a working powervalves that i know of. ESR built 2 that were opend and closed with a cylinoid mounted on the left valve. They had to have a battery on the quad to run it and the rpm was adjustable with a pot. Another pro that at one time had suzuki support I believe had one on his honda that was driven off of the waterpump area. I can't remember his name right now but I know the esr's worked very good and nothing 250cc could touch those 2 around 87-88 on a TT track. After working with the 89 cr cyl and plugs for a little bit Eddie parked the working pv even on his own quad. 85 cr cyl were also used largely because of the water jacket before the 89ish cr cyl.

[troybilt]

This guy did it on his ATC:

http://redrider.embarqspace.com/#

[etccb]

That is simular to how the other one was done. It is funny to read him talk about the power band hit, lol. It would hit for sure.
It was an animal. It's not worth it any more with all of the cyl that are now available but back then it was very trick until Eddie worked with the pluged cyl.