Thoughts on billet powervalve coupler

[vectisitch]

So my powervalves are badly worn on the coupler ends and the coupler is worn too. To my mind this system is a weak point.

I know the gen yamaha ones have the rubber top for some movement but surely this causes the wear??

My thinking says that if you fit a solid billet coupler to stop any movement then the pv won't ever wear on those points?

Why did Yamaha decide to add the rubber part? If the barrels are tightened down on the cases then there is no movement between the barrels and the pv's should move as one, the whole point of the coupler.

My pv's were way out of sync and the bike felt nowhere near as powerful as i was expecting when i first rode it.

[headcoats]

Great question, I would love to know the answer too !

[lc2]

It is possible to fit an Oldham coupling, I have done it previously and they allow for misalignment.

[JonW]

Wicked made a billet PV coupling, it worked well. Dont know if they still do them.

The rubber part is there in case one set of PVs seizes i think.

[marrcel]

I tried a solid connection but then one of the pv grinded. Some flex was needed with my setup.
May yours not.

[andy748]

Don't think Norbo sells them in billet but Martin does, look a nice bit of kit. Andy. www.mb-designs.co.uk/shop/Billet-Power-Valve-Coupler-p257265522

[badger1]

www.mb-designs.co.uk/shop

They do them.

[vectisitch]

I've got one from mb designs. I just wondered if my thinking was sound

[bare]

Sept 28, 2021 10:17:31 GMT 1 vectisitch said:

Why did Yamaha decide to add the rubber part? If the barrels are tightened down on the cases then there is no movement between the barrels and the pv's should move as one, the whole point of the coupler.

My pv's were way out of sync and the bike felt nowhere near as powerful as i was expecting when i first rode it.

Basic engineering practice.. Solid connections between two virbratory elements causes nothing but problems .
When You design an engine... feel free to do what you wish.