New to the M20 world, were there different styles of the BSA M20 Oil Tank? Early war, mid-war and post-war. If so, please post pictures of the front, rear and different style details. Thanks!

email (option): questmasters(at)hotmail(dot)com

I think the shapes are all the same.
Only postwar tanks got a hole in the back around '47 for the speedometer cable, coming from the gear box.
And early tanks had a different cap.

The 1936/37 oil tank was completely different having a 4 bolt fixing in the side (as you look at the bike from the timing side) and two mounting brackets for it on the frame. It was also a different shape and had a screw in top....The next tank was the more familiar shape and had the later mounting arrangements but retained the screw in cap...Later again the tanks had the 'flip top' cap of the type fitted to WD machines...

Post 1947 tanks had the hole through them for the speedo cable and the flip top cap...I think I'm correct in saying these tanks was also a little wider to compensate for the cable hole...I'd have to check to verify that point though....Ian

email (option): ian@wright52.plus.com

That's right.
But could it be that there were 2 types of flip top caps ?
The earlier one had a more round/bolar top and the later was flat (if i'm not mistaking).

Any one else ?
Or a picture ?

I can't remember the details right now, but there has been debate over the years about those flip caps with the round 'T' handle. I think they were made by another firm as an aftermarket replacement for the BSA caps?? Lex has the story. Ron

email (option): ronpier@talk21.com

Please keep the info coming! I love knowing specific details about individual parts as I restore the parts for my M20.

I read that the early style M20 oil tank cap had brass somewhere on it? Perhaps the wing on the top to tighten it closed?

email (option): questmasters(at)hotmail(dot)com

I have the correct BSA caps on my oil and petrol tanks both are plated steel caps with brass 'T' handles. Ron

email (option): ronpier@talk21.com

Ah, Ron, that's why you asked! I was talking to Henk about this last sunday, and he avoids them like the plaque, as they are only seen on postwar rebuild pictures, never ever on early or prewar bikes. (the brass ones with the rounded T)

Then there is the patent date of 1942, see picture below, it was all on here a couple years ago anyways.





Cheers,

Lex

email (option): welbike@welbi(XX).net (think about this!!)