Pulling apart my '70 A65. I understand you usually can't get thru project like this without a surprise or two, but this one just has me shaking my head.

Looking at the oil supply port to the head, I blew some solvent thru to make sure it was clear. - I see about 1/4 inch of the two ends of a cotter pin sticking out where it exits below the intake rockers. I was able to push it back out, but have no idea how it could have gotten there. I was too big to fit thru the flare fitting on the head so it couldn’t have worked it’s way up from the oil tank.

The cotter pin (split pin) is meant to be there to regulate the oil flow to the head, don't ask me how it's supposed to work and it's not even in the parts diagram.

However BSA A65 repair manuals for years 62-65 and 71 in Section A6 "LUBRICATION" mention that "feed to the rockers is metered by a split pin at the base of the centre pillar".

I read this and immediately ran to my shop manual.
I take back what I said - finding a cotter pin in the oil port wasn't the strangest thing yet. Learning that it is suppose to be there is!!
Back it goes--

Welcome to the wonderful world of BSA. Particularly the land of A65.

I read this and immediately ran to my shop manual.
I take back what I said - finding a cotter pin in the oil port wasn't the strangest thing yet. Learning that it is suppose to be there is!!
Back it goes--

whatever works, you know. it's a particular mindset of common-sense engineering, like that friend of mine who fixed her leaking toilet by stretching a condom over the . . .

well, never mind that one.

Well, there could be no claims of unexpected pregnancy through sitting on that dunny !