can I pick your brains for a moment?
My 1954 ES2 leaks some oil from the driveside, barrel to crankcase mouth seam. Located just there is the oil passageway that channels oil to the cylinder wall. The leak is originating from this. It stops for a while after I change the seam gasket but starts again once some expansion and contraction has taken place. I have tried most commonly known gasket cements etc., but nothing really works. I was wondering if I could just block this passage off as anyway the cylinder bore must still get enough lubricant from splash by the crank wheels. Has anyone else experienced such a condition and blocked this off? Many thanks.
... it shouldn't leak. Have you checked they're flat? I use Wellseal on one side of that joint (a very thin smear applied with a brush) and grease on the other side of the gasket.
I'd work on the basis that the feed is there for a reason.
By the way I thought the passage was on the timing side as it's fed from the pump but I haven't been in there for a while.
Yes the feed is at the back of the timing side half but for the amount of oil coming through can be the only source. The breather is fine so no worries there. As an alternative to blocking i could insert a tube that would bridge the gap between the crankcase mouth and barrel. The oil to the cylinder wall was eventually discontinued and when I got the bike originally this hole was found blocked, which makes me think that the previous owner was suffering the same problem.
Many thanks for your advice,