2000 CR 250 Exhaust Valve

[Green=Go]

Here's the skinny. I rebuilt the top end of the bike. I never took the exhaust valve apart, just cleaned it up as best i could. It operated fine when i moved the arm back and forth on the side of the cylinder. Here is where I think I screwed up. I put the cylinder back on bike and checked the valve again to make sure it acuated and it did, it opened and closed just like it should. The only thing is that the valve is in the up/open position instead of hanging down like I think it should be. I started the bike with the cover off to see if it went in the down position while running and it did not move. I guess the question is, is there any way to fix this without pulling the jug, and making sure that the valve is in the down or closed postition before sliding it back on the bike where it meets the thing coming out of the case. I have no low end whatsoever and I kept thinking it was jetting, but this sounds like my problem since the bike ran fine before. Any input would be greatly appreciated. Thanks

 

[dirt bike dave]

IMO, you have not properly aligned the 'fork' on the right hand side that activates the powervalve.

This is a common mistake people make on '92 - '01 CR250 rebuilds.

You will have to pull the jug and align it properly before reinstalling cylinder.

Will cost you a few gaskets and some hassle, but it does not take long.

Overall, it's a great powervalve design, but if you don't align that fork and peg when you put it back together, it doesn't work.

 

[Green=Go]

Should I have the arm on the right side of cylinder in the back position so that the valve is closed/down when I set it down on the peg. then just adjust the fork on the bottom of cylinder if it doesn't line up like it should.

 

[dirt bike dave]

It's been a few years since I had my '99, but if I recall correctly, match the fork to the position of the peg, where ever the peg is.

Ideally, this is the powervalve closed. But if the PV is part open when you put the jug on, the PV will go to the correct position when you start the motor.