Hello,bought my second BSA WM 20 today.I have a some questions.

1 key card info frame WM20.846341,blok WM20.8463.. last two hard to read.

2 carburator 276 AW/1BB ? wrong one?

3 on the frontfender numberplate HWC38H, is that the civilian number?

It had stand still for 15 years.

regards Roel

email (option): roel3@hetnet.nl

Roel, The 276 AW/1BB belonged originally to a late 1940s B31 / B32 and is 1 1/16" bore rather than 1".

The registration number looks like a civil UK plate and indicates that it was registered in Sheffield between April and August 1970. This probably indicates that it was fairly late coming out of service.

Hi Roel,

Are you sure about the frame number, number WM20 846341 is not an original frame number. WM20 numbers go up to about WM20 120000

Henk

email (option): ahum@quicknet.nl

Hi Roel,

Are you sure about the frame number, WM20 846341 is not an original frame number. WM20 numbers go up to about WM20 120000

Henk

email (option): ahum@quicknet.nl

Hi Henk,the last two numbers 4 and 1 ,looks like the stick together like a H.

groeten Roel

email (option): roel3@hetnet.nl

Hi Roel,

Could you send me a photo of the frame and engine numbers?

Henk

email (option): ahum@quicknet.nl

Hello Henk

I PM you.

Roel

email (option): roel3@hetnet.nl

What do you people make of these numbers, they look quite original but very strange at the same time.

Henk

email (option): ahum@quicknet.nl

I suspect both frame and engine to be WM20.84634. (4 in engine number damaged)
With the subsequent possible H and or 1 being unrelated to BSA serial.

email (option): n.gentner@bigpond.com

I think that the frame number has a "typo", an accidentaly stamped extra digit.

Its not that surprising that someone would make some mistakes in the factory continually stamping numbers all day.

But I'm not sure if the last digit on the engine is a 1 or a 4.

Rob

email (option): robmiller11@yahoo.co.uk

It seems that the 8 in the engine number is upside down but all in all it does look original doesn't it?

Henk

email (option): ahum@quicknet.nl

My take on it is the bike was stamped 84631on engine & frame.
the 1 has been changed to a 4 & a 1 added to the end,either at factory or later.
what detail has the frame at the seat front swivel mount, is it seperate saddle mount ? or incorporated with rear tank mount casting ... maybe a further clue to year/frame number.

We don't of course know at what stage in the process the parts were stamped but it seems evident that it would have been impossible to marry up pre-stamped engines and frames at some point on the production line.

If the frame stamper put on an extra digit, there is a good chance that the engine stamper would copy it before he realised his mistake. I'd suspect that it was intended to be 84631 but somehow 846341 was stamped and they then tried to correct the '4' to a '1' and ignored the last digit or perhaps filled it cosmetically at the time. Someone has certainly tried to convert the '4' on the engine but the long horizontal stroke is a giveaway.

Do either of these numbers appear in the cards ?

If it were mine, I'd remove all the paint on the frame tube and have a good look to make sure that there were no flat areas under the number. I suspect that I'd use a bit of body filler and /or silver paint to make the numbers match the vehicle documents.

Here are some pictures,hope this helps.

Roel

email (option): roel3@hetnet.nl