£128.00
WD BSA WM20 Outer primary cover with Inner primary chain case cover.
The outer cover is stamped clearly with 66-7503
I imagine that this pair of primary covers will do for a standard M20, rather than just the WD WM20. However, I understand that this outer cover is for the War Department WM20. The number is stamped on the outside of the cover. It is 66-7503. I believe it is listed as part number 66-7502 in the parts book.
The inspection hole is 1-3/4″. I understand this may be one of the features that indicates the War Department use. It also doesn’t have the added flange on the outer edge.
There are many people using standard WM20 covers on the WD bikes. Here is your chance to buy a pair of WD WM20 Outer primary cover with Inner primary chain case cover.
Condition of the WD BSA WM20 Outer primary cover with inner one.
Good, given how old they are.
Most of the paint has gone and they have mild pitting. There are some very tiny dinks to the clutch dome. However, for the most part, they are dent free.
Please study the images for overall condition.
Other BSA parts for sale
I still have some. If you are building a unit-construction 500 twin, talk to me. I haven’t got around to advertising everything, but I still have quite a few parts to go with this set of WD BSA WM20 Outer primary cover and inner primary chain case cover.. View some of the parts for sale
Sometimes, I put a notice up on TheTimingChest Facebook page letting everyone know that something interesting is about to become available. It may be worth following the page.
Buyer notes for the WD BSA WM20 Outer primary cover
Shipping is charged ON TOP of the price for the item. There are too many variables to include shipping in the checkout, so please contact me before you buy and I will give you a shipping price.

66-7503 WD BSA WM20 Outer primary cover Inner primary chain case
I usually ship to most destinations.
International shipping available. Let me know where you are and I will send you a price for shipping with tracking
Combined shipping available.
Viewing: Please come and check it over before you buy. It is at PE28, near St Ives in Cambridgeshire.
Collection: If you don’t want it shipped, I have plenty of space. If you can’t collect for a while, it’s not a problem. However, I will need to be paid very soon after the sale. Thanks.
Payment: Good old fashioned money on collection is preferred. I can accept payment through PayPal or by bank transfer as well. I can accept EUROS. Please ask.
Import Taxes: Please note that IMPORT DUTIES are not something I can control. If you are buying from outside the UK, there is a chance that you will have to pay import taxes. Import taxes vary from country to country. If there are charges to pay, it is the buyer’s responsibility to research the cost and pay the duties. The price that you see on my advert is for the item and not the item plus whatever taxes might be due.