Different power valves

[jimmydc98]

Does anyone know if these 2 are compatible in the same cylinder they both say 3bn and the one without the o rings next to the exhaust came from a 3mb cylinder

There is also a variation on the powervalve head I presume the diamond shape was mainly on UK models with the fixed powervalve so they could restrict power and then you could change it yourself from the 2 different settings where’s the rectangle one would only go in one way but I may be wrong

[Calum]

I know the powervalves you get from the 3BN cylinders are not interchangeable with other cylinders.

Those valves look wildly different so I'm not confident to say they both fit properly.

[SpookDog]

@jimmydc98

The diamond shape is irrelevant, the power valve never had a servo pulley fitted to it. You can position the valve where you want then tighten it up with the end bolt. If you fit a servo you need to change the ( gear lever side) bush to allow for rotation. Otherwise it clamps the power valve...

[Nottsbiker]

As mentioned the diamond shape fits the pulley with the square / rectangular end as well

The grooves in the power valve aren't for O-rings, instead these fit into the ends caps as you cant refit the valve into the cylinder with O-rings in the grooves