I wasn't getting much visable smoke either, but the inside of the tail pipe was oily soot. Also the spark plug was very sooty.

Have you checked the rocker oil feed and drain lines for leaks?

Check around your barrel. If the oil is starting just below the head/barrel joint, it is coming from the combustion area. Also, the same oil gets blown back on the carburetor, dynamo, magnito, battery making a sooty mess of the area. On every ride I was getting a little river of oil running down the crankcase just below the forward left head bolt making me think that the oil was coming from the barrel to crankcase joint, or the bottom of the head bolt inside the crank. But not in my case. It was running down the head bolts from top to bottom.

GeoffRS
See this post:
https://www.bsaownersclub.co.uk/bsaoc_forum/index.php?topic=9041.0
A brief summary:
Put 400ml of oil in the gearbox, or fill to about 1.0 to 1.2 inches below the gearbox main shaft centerline.

In the link I added above, it indicates that 370-400ml of oil brings the oil level in the gearbox to about 1.0-1.2 inches below the centre line of the main shaft for the older style gearboxes with the round screw on cover on the right side.

This is very easy to check. The bike should be vertical. I use a nylon tie wrap as a dipstick, push it down vertically into the oil, press it against the clutch adjustment bolt (which is at the centre of the main shaft) with my finger tip at the centre of the bolt. Pull out the tie wrap and measure the distance from my finger tip to the oil on the tie wrap.

I use SAE50 in the gearbox.

I had a flat tire last week and had to have my 1957 A7 transported home on a flat bed tow truck. I think the driver may have been a little to aggressive on cinch down of the front end because now, in the garage, I have two little puddles of oil on each side of my front wheel.

Has anyone had this happen? I am wondering what kind of damage has been done to the fork assemblies. Is it possible that oil was forced through the seals without actually causing damage, and the oil I am seeing is what accumulated in the chrome seal housings. Is this thinking too optimistic?

Thanks Julian
I have no recess, so no washer.
However, where is this thin/thick o-ring?

In addition to all the above, I get more consistent results for setting idle if I use 91 octane fuel with no ethanol.

Hello B. Murphy
The older configuration gearbox spews out oil if you put 1 pint in per the BSA recommendation. See this post for more info:
https://www.bsaownersclub.co.uk/bsaoc_forum/index.php?topic=8337.0

For the primary, put in the minimum amount of oil. The level should just touch the bottom of the chain. On my C11 I have stopped putting oil in the primary and periodically lub the chain with rear chain lub. Ensure the clutch bearing has grease however.

For the engine, it is best to do some investigating to determine the source.

Could be the shifter forks are not sliding freely in the dogged wheel slots. Caused by:
-bent forks
-incorrect shimming of the shifter shaft