Powervalve issue?

[Jim Cook]

Originally Posted by poelinca

Bumping in this thread as i am still chasing down a rattle. It comes from the left hand side tough, low rps while the bike is moving.

What i want to find out if there should be play in the PV actuator arm and the PV actuator plate, here is a video i made a while ago
https://www.youtube.com/watch?v=QuJqHtTPUzU

Should i tighten the nut down to remove the play in the arm ?

Regarding a rattle in the pv assembly:

You can tighten the nut a bit, but as was stated, be careful because the stud is "fragile" and will pull loose from the bracket easily. I heat mine retaining nut before removal, and then replace it each time with new 5mm aircraft style locking nut. (mcmaster-kerr is your friend.)

Make sure that you don't need to take the slack out of your pv linkage by adjusting the bell crank governer that it is connected to. This is the cause of most pv rattling. This issue is covered in the forum quite thoroughly.

Also, make sure that you have the spacer behind your pv bracket installed. I saw some bikes come from the factory which were missing the spacer. If you look at this part diagram, you will see it as part #36 in the diagram. http://partsfinder.onlinemicrofiche....YLINDER%20HEAD

I hope this helps you.

Good Riding and Wrenching!
Jim


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[Jim Cook]

Originally Posted by Lotus54

Just learning about the GasGas style PV.

I have a 2000 200ec.
From what I ca tell, the PV is pretty much the same for all of them?

The pivot does sit against the stop, but almost no pressure at all will allow a couple of mm movement.

I get a rattle, but more what I am trying to solve is lack of bottom end and a hard hit.
I know is is a 200 not a 300, but I'm trying for best bottom end power and less top end. As linear as I can get.
If I drop 10hp on top that is just fine, maybe better.

So...from my description does it. Sound like I need to pull the side cover and adjust it?

Any other ideas to get what I want is welcome (already flywheel weight).

Mark

I don't know which exhaust pipe you are using, but if it is not the FMF Gnarly, you can pick up good bottom end power with that pipe.

It made a huge difference in ours, compared to the stock GasGas pipes and the Messico pipes.
That, and proper jetting and good compression.

[Zman]

I was in a bind before a ride and wanted/needed a quick fix for a slightly loose PV actuator rod. I used two pairs of pliers to slightly tighten the bend in the actuator rod. it took care of the slop and worked fine.

[stian]

Wanting to know if there is any clearence for the right side of the half-moon bushing, and if the silver-bushing is supposed to go round and round?

The silver bushing needs to be pressed with quite abit force, and is stuck there.
The half-moon do not turn around easy, as the double-bearing left side. It is as its some casting-flaws in where the half-moon bushing are supposed to sit. There is also 0,5mm play.

Anyone?

[Munch]

Which washers are people removing to make the powerband come in quicker? I haven't seen much discussion on it in this thread.

Do many people do it? Does it make much of a difference?

[Jakobi]

The shims/washers preload the spring behind the governor. Rhs of the image.


See em!

[Munch]

How many should I take out? I want the powerband to hit a bit harder/sooner. I feel like the power is a bit too boring.

[Jim Cook]

Originally Posted by Munch

How many should I take out? I want the powerband to hit a bit harder/sooner. I feel like the power is a bit too boring.

What year and model Gasser are you riding?

[Jakobi]

Mine only has one in it. It's the darker shim hard up against the left hand side of the spring. I didn't remove any and haven't bothered making any adjustments.

One thing to note though is that the shim is simply your preload on the spring. It won't change the rate at which the PV opens, and in many cases if you have the PV open too soon you'll notice a dip in the power curve until the engine can catch up. Opening earlier doesn't mean more power.. think old school PVless bikes that were nothing off song and then everything at once!

[barossi73]

All the powervalve does is alter the exhaust length.think of it as 2 exh pipes,1 is tuned for low revs,the other for high revs to take advantage of the 'supercharging' effect.previous to pv the pipe was by necessity a compromise resulting in a narrow powerband.
The powervalve is the switch between the 2 pipes,opened by centrifugal force at ?revs.not saying there arent small losses/gains to be had,(i havent explored)
just trying to clarify the powervalve/powerband thing