i am fixing to do it on a 1998 yz250. i have to remove the exhaust valve lever, the pushrod arm, the bolt and the washer to take the cylinder off. my question is why do i have to do this to take the cylinder off???? thanks
and also i don't have to take the power valve apart if it don't need it do i???
Usually the power valve actuator goes through a hole in the cylinder head area. No, you don't HAVE to take the power valve apart but you should since the cylinder is out. It's the best and easiest time to clean it up from the goo. Trust me, if you have to do it later, it's alot harder with the cylinder on. Do it, you'll be thankful later. ;)
On this bike you really should take the powervalve apart. As the valve and stop wear it can let the powervalve hit the piston.
If it is touching, this will quickly ruin your new top end.
It is a very simple design to open up. You are only one hex head bolt away from having it out by the time you get yoru cylinder off.
Grab some sort of owners manual and go for it. This is not a difficult engine and powervalve to work on.
If you want, send me an e mail jamesc4085@msn.com. I happen to have a picture of my powervalve on my 97 broken down. Once you see this your not going to worry about it.
When I tore my topend down I did not indicate to loosen the allen screw before cyclinder removal. With the cylinder off it wouldn't come loose. How big of a job is it to remove and clean the power valve with the cylinder in place? Is it normal for the power valve to "ooze" on the right hand side near the rubber gasket of the power valve linkage cover?