Powervalve issue?

[twowheels]

Originally Posted by knobbyboy

...check out the pic and let me know what you think. It looks fine to me. But then what is that sound? Can the parts of the actual PV wear out? Guess i'll know more when i tear it down. Fork and shock already out to be rebuilt. And as far as low end power loss can't notice much there apart from likely needs rings anyway.

The zero-rpm position of the actuator plate looks fine to me.

Beware the knock that increases but that you can't find the source of. I had a KTM 200 do that once - it had never run stronger, then the knock ceased ... when the crank pin bearing let go

When you've got the top end off take the time to check rod play, and it likely wouldn't hurt to remove the ignition cover and see if you can move the stator up and down excessively.

[GMP]

PV rattle typically presents itself at idle and when the revs are dropping to the point of the governer being in its "home" position, with no preload on the system to take the slop out. On a GG motor, they can rattle a lot if they need adjustment, but once adjusted they should stay that way. There is a remote possibility that the bellcrank setscrew has come loose, but I would then also expect you would not have full PV travel and normal operation.

[knobbyboy]

Thanks. i don't feel that the linkage is "undone"- i can feel the spring pressure when i pull on the rod. And my rattle is not at idle, its fine at idle, its from about 1/4-1/2 throttle. Once its past 1/2 throttle don't really notice anything. Gonna check that stator for movement tonight like twowheels suggested...

Good news - my PV is just fine. I'll post the real problem in the general engine section...

[Zman]

Hello All,

I noticed from all of the photos of the PV actuator arm, members are running a mix of bearing seal orientations. Some appear to be open to the outside and some apear to be sealed to the outside.

Which is correct or does it really matter since it appears that we have a mix? I read that these bearings will get lubed from the exhaust gases, but that sounds less than ideal.

I presently have a mix. On the shifter side I left it open towards the exhaust port because there is no other oil source, but on the kickstart side I left it open towards the linkage/trans side thinking that I might get enough oil splash from the trans through the linkage hole to lube it. In hindsight that hole is pretty small. Do I need to change the bearing orientation or learn to do stoppies?

[GMP]

Over the years owning a few GGs I've seen a mix from the factory as well, from metalic sealed to full open. Yes, they count on lube from spooge oil, and this is no problem. If you run an oil that burns and/or gums up then it can be a mess at top end time, but with a high flashpoint oil like Amsoil everything is free and clear at 100 hrs. The metallic sealed bearings are not an actual seal and will pass exhaust gas and spooge through, thats why even with these the right side PV cover area is black, and why your trans oil will get darker if you do a lot of slow technical work.

Occasionally these bearings will get loose, and PV rattle increases. Not from load or lack of lube, but IMO from a short arc of operation over the same area, and a lot of vibration. I use single side sealed bearings with the seal side out, with the exception of the inner bearing which is open. Get good quality bearings, many of these are cheap third world junk for skate board wheels. Good ones are cheap anyway, and it costs more in time to clean the old ones during top end time.

[Zman]

Thank you Glenn!

Originally Posted by Jakobi

You are correct. You want the lower right hand part in your picture to be up against the bolt/stop while the bike is at rest which is also = power valve fully closed. I don't have the arm connected in this pic as the jug is on the bench top, but thats the position you're looking for with the bike at rest, everything assembled. You want enough tension on it so that it holds itself there under idle.

So i am still dealing with a poor performing PV. I got into it further. When My plate is on the stop the PV port is fully open. I can see the opening from the shifter side PV cover. When I rotate my PV plate to the opposite stop as if full throttle, the port is rotated to block the opening. This seems backwards to me. I see no way to alter this orientation. The actuator plate is indexed and only goes on in 1 direction. Any suggestions???

[timlh]

Ron, I had the exact same problem. My Power valve was working backwards. I took it apart and put it back together and it worked correctly. I still don't know what changed or was assembled incorrectly the first time. But when I reassembled it. It worked correctly BTW it was my 4th top end rebuild on the same bike when this happened. I've done another 10 or so top ends and 4-5 bottom ends. Never had a problem like it before. I will say that I payed a lot of attention as I reassembled the 2nd time as to how each piece was lining up.

Good Luck, Tim

Turns out that mine was oriented correctly. I simply didn't understand the flow of gasses correctly. All is good now with that. On to the other issues!

[justsam]

Firstly thanks to all you guys here, some real useful tips on what I'm trying to achieve. I have a 2010 EC 300, which I use for extreme/hard enduro's in the UK, so basically I'm trying to soften the hit of the PV without spending ?300 on a Trusty Kit and also erradicate the annoying rattle. I've inspected the PV mechanism and found a fraction of play which I've adjusted out, as said before in the thread. It runs fine and quiet but I need to ride it properly to see how it feels.
I also read that removing the shims, allowing the PV to open sooner, actually gives a more progressive power delivery???.... Has anybody else had experience of this?
As for the Trust Adjustable Kit, how does this work? Does it act as a limiter on the PV mechanism or does it just dampen or slow the action?
Any help would be massively appreciated guys...