I rebuilding a 1300 cc case ,looking the the 6 of 12mm case bolts there is no taper at the base of the case for the O ring to sit in , this is the seal to stop oil going up the case bolts .

was this a change made to cases later on ?

ideas

must be a hard one me think !

Hi

It was a later innovation, just make sure you put some sealant on the nuts. A man with your talent be able to retrofit.

1302Steve

Yes I counter sunk some O ring groves steve , should be good for 30 years more running .

lots of small changes over the years , making things better .

a little dab of sealant on the washer and nut works well. Just make sure it isnt the type that goes hard

Hi

I always use Curil in cases like this.

1302Steve