How does this RM125 Powervalve work?

[honda_power]

Wondering what makes the powervalve lever move up and down... Trying to figure out if its working or not (its not runiing - gotta get a flywheel nut and rattle gun sometime)

The large cog thing also makes a rattling noise... kinda like there are loose bearings in it. I cant seem to be able to pull it apart though. Normal?

[noobi]

Where does the big cog thing fit into the cases, is it the hole on the right that the pv arm works off?
It could have ball bearing inside it and a cage shape thing, so when the cog reached a certain speed the ball bearings fit into the cage and push the thing on the shaft into the pv pivot plate and actuate the arm, and the things that look like roller bearings are where it runs on the pv plate.

Just sort of thinking out loud here though. Probably wrong

[honda_power]

yeap into that hole. You could actually be right, didnt think of that... dont know how it would engage the arm, but who knows. Guess ill just run it without the lever cover

[noobi]

That was the other thing I was going to suggest, but wasn't sure if it has a powervalve cover on the jug, not sure if you should run the engine without the primary cover ( the big one ) on. But I guess if you ran it for only a few seconds it wouldn't matter.

I think the roller bearing on the shaft thing means it can run on the pv plate and turn it so many degrees to move the pv but whilst fully open it doesn't drag.

More thinking out loud.

[B0000M]

its an RM..... it probably doesnt go at all...... lol

[barty5]

http://fiche.worldofpowersports.com/...e=13&A=228&B=3

did you get this bike from up north ???

[CookMySock]

Usually there's a set of rotating weights in the governor that move outward with increasing centrifugal force, overcoming the force provided in the opposite direction by a spring, once a certain rpm is passed, pushing on the arm to open the exhaust valving.

Steve

[honda_power]

http://fiche.worldofpowersports.com/...e=13&A=228&B=3

did you get this bike from up north ???

Hmmm looking at the diagram i may be missing numb 24 "ball". Kinda hard diagram to follow as it has both 01 and 02 levers on it. Cant really tell where the ball goes though. I havn't been able to pull the stator or actuator off, screws are so friggin tight ill strip them

I dont know what you call 'up north'... I got it from auckland. Iv had it for ages, been working on a xr250. Now that im about to run it again with a new wisco i dont really want it to blow again so im checking everything out.

Usually there's a set of rotating weights in the governor that move outward with increasing centrifugal force, overcoming the force provided in the opposite direction by a spring, once a certain rpm is passed, pushing on the arm to open the exhaust valving.
Steve

Thanks for that... I guess that explains the rattling noise in the governor. I still don't see how the governor engages the lever, but at least i dont have to fork out heaps for a new governor

[bogan]

looks like the num 24 balls (shud be 3) will be behind the PV actuator plate, but I'm not seeing how the govenor tranfers torque to the actuator, isn't there bearing in the middle preventing that?

Just had a mess round with my powervalves in the weekend, they were set to go from open to bash into powervalve covers even more open, so set them properly and gained heaps of midrange Usually a cover you can pull of when its running to check if they are operating correctly.

[honda_power]

oh yes i see now... pretty obvious eh, shouldnt have missed that. in that case its all there.

Thats what i am wondering, the actuator has rollers inside it, as well as that bearing that sits between it and the governor.