Rubber between clutchplates?

[Allan k]

I noticed that my spare 550 engine has rubber ring (square o-rings kinda) between the clutch plates... The workshop manual says nothing about this, and my primary engine didnt have this either

Schould i fit them or skip? What are they for anyway?

[yeadon_m]

Alan, I have them on my 550B. No idea what they're supposed to do. The parts list I saw says they are V-rings, not present on 380/750. Interested to hear theories. It must be to do with oil inclusion or exclusion and I'd guess to do with clutch slip or over heating.
Cheers, Mike

[Vintageman]

I wonder if these are like what is in my Yamaha r5 (rd350?). There is a large rubber square O ring between each metal disk and fiber disk. If so these ensure all plates open and evenly. Without these one or more metal fiber disk may stick together... at least when cold. serve some damping too.... some guys remove for say causes slip, but I can attest they stick when cold without and really no difference when in given you have good springs