A65 engine breather.

[DAVE BRADY]

Hi,

Why are these two A65 breather discs different?

Dave.

[Dean Southall]

For different cams/valve timing?

[DAVE BRADY]

Hi Dean,

Perhaps but the breather works more in relation with the movement of the piston.  I had look on line and I reckon that they were all the same for A50/A65.  I did find a reference to some pattern one bing made wrong so maybe I have one of those.
Now do I destroy it to prevent inadvertent fitting or keep it a curio?

Dave.

[DAVE BRADY]

Hi,

Thinking a bit more about this there could be more to Dean's suggestion.
I have heard that as part of tuning the cam can be advanced a few teeth so advancing all of the valve timing.  As the breather is driven by the cam this would also advance the timing of the breather but I reckon as this is to with the descending pistons it is now out of synch.
So a disc with retarded pegs or cut outs would be needed. 
I either have a badly made part or a rare specialist tuning part.

Dave.

[Allan G]

Hi Dave, don't know if you got to the bottom of this.

I went to look in my garage as I should have a few lying around, but alas I couldn't find any. Anyway scanned through SRMs website and found the ones they list are as I remember them, with the tabs in the same position as the windows.

Anything also will invite oil leaks, unless your cam is also a tooth out of phase

https://shop.srmclassicbikes.com/product/rotary-breather-disc-a50-a65-t110-t120-702254

[DAVE BRADY]

Hi Allan,

No real answer yet so just there as a curiosity.

Dave.