With the generous help of forum members and services offered on this site, I am beginning to piece together my WDM20. Bought in 1987 largely in boxes, it was represented as "all there". By weight it's probably 98% there, but by the part maybe 90%. My inspiration is my oldest son, who started riding last year, and I'm keeping a promise I made him some years ago.
I'm looking for some help in determining the contract number for my bike. The frame # is WM20118274. The engine, however is a different #, WM2081813. Do I need to be concerned with 2 different contract parts books, or do the engines follow a similar specification throughout?
Next, how do I go about finding a "C" number for the tank? I guess that follows the contract number; mine is later than anything in the chart found on this site.
Lastly, is there a "key card" for my motorcycle?
I must confess it feels strange just throwing these question out into the ether. I know there must be someone or some few who can answer, but I don't know who to address them to. Thanks.

email (option): siradrad@verizon.net

Hi Damon,

Your bike isn't in the key-cards, but WM20 118271 is and has tank number C5887371. Your bike would have had C5887374 as tank number.

Originally your bike would have had matching engine and frame numbers, your engine is a few years earlier. I have no good photo of a bike with a tank number close to yours but it would have looked pretty much the same as these bikes.

There is not a lot of difference between the engines of early or late BSA's.

Henk

email (option): ahum@quicknet.nl

This is as close as I can get - C5888416 - It looks to have 'Canadian' padding although the location looks to be tropical so perhaps it was adopted by other colonials too ?



You should be fine with any late-war parts books Damon. Any diferences will be in the smallest details and not significant unless you intend to take up rivet-counting (a much underrated hobby, in my opinion )