Breather pipe o-ring size?

[Mr. Max]

I noticed a slight oil leak between valve cover and breather pipe, it seems that there is o-ring (part #43 on pic), what size o-ring is that or do I have to get Yamaha o-rings? It takes couple of weeks to get yam stuff here. Anyone?

 

[one2dmax]

The part numbers sometimes can decode to the oring size but most of the time it doesn't. I have zero idea what this would work out to. I stock a lot of OEM parts but not sure i'll have these (unless it's shared with a gen 1 oring which I am not sure it does).

 

[Mr. Max]

I ordered couple of these, original parts, but didn’t measure them though. No more leaks anyway