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So my 91 200 has had no top end power since i got it 3 years ago, awesome bottom end though. Got around to actually take it apart and the left and right powervalves are junk. Center one is good.
I dont think this thing is worth buying $200+ steel valves for, since i paid 300 for the bike.
I have read in various places that people who race these bikes silicone them in one position or take them out.
Has anybody here tried this?
Is there a good medium position for the valves or are they made to be full open/closed only.
Im willing to lock these things in place just dont know what a good position would be.
Any thoughts?

Depends on the riding you want to do the most of. Leave them out and WOT will be fine, but everything below about 6500 rpm will suffer. Leave them in and closed is the opposite. You could probably try to lock them in the half open position and just squash your entire powerband. If you only paid 3oo for it and are still riding it, it's worth the 200 to get it running right, unless you're ready to drop big change on a new ride. Just my .02

Welcome to kdxrider.net.

I have been on dirt bike forums for about 19 years now. I have never read of someone siliconing subvalves into place.

Fully enjoying dirt biking is not a cheap hobby. I hope you keep at it and find enough joy in it to commit some more resources to it.

Beer and Powervalves are proof God loves us.

I found some other valves from motoduro for a bit less. Weird how the only 2 places making these are in england... Probably going to get those since I really dont feel like taking it apart again if i have to mess around with it. I work in a machine shop so might look into fixing my valves or making new ones also

Congrats on pushing on through. It is tough sometimes when big problems pop up.

I asked my buddy about this (he has a few RD RZ 350 & many dirt bikes). The only time he knows of is sometime power valves get eliminated on RD to install banshee cylinders. And also the get run inop, if owner doesn’t have $ to fix. He said he’s seen some like that when living and building bikes in Brazil.
He’d also never heard of doing it on purpose for a dirt bike.

In case anybody is interested, I got sick of waiting for motoduro to get the valves back in stock.(they still dont)
The left side valve was still in one piece, with just teeth missing.
I found the correct off the shelf gears to match the stock gear on the valve.
Turned the old gear off, pressed on the new steel one and locked it on with a dowel.
For some reason i didnt take a picture of this one finished The other valve was broken in 3 pieces
I made a new piece from where the valve necks down up
Turned a locating diameter in the valve to keep the new stainless part concentric Drilled and tapped a 4 bolt pattern into the valve, made the wrong choice using #6 screws, should have used #4 as the heads are too big on the #6 and I had grind them after installed I will get some more pictures of them finished with the gears on them.

Wow, good job!

Heck yeah! Congratulations!

I have a drawing of the bolt on piece, if anybody wants this let me know

It looks to me as if the gear installed on your right valve is upside down, the gear teeth need to be in the same plane for the actuator rod. Could be that your gears are only half as high as the OEM ones so you still get rod engagement? Ingenious work around either way

You are right the right gear is upside down in that pic, I was going to use the original idler gear and that way put it in a spot with no wear on the teeth. I decided to make the new idler after putting that one on. It is reversed now so It is in the same position as the left gear.
Anybody know what that flat is for on the idler? I dont understand that decision besides maby to save weight

Wow! That is so cool. Nice work.

fxnick, I think the flat part is to keep the collar from spinning in it bore.