Hi From Denmark

Could any of you halp me?? What carburettor should bee on my M20 de luxe 1939. Frame no. KM20 1923, engine no. KM20 800. And the set up of it, would bee very helpfull.

Regards Bo

email (option): bo.orloff@gmail.com

Bo.Here are the relevant pages from the Amal catologue. I can't get it on my scanner in one go. So I'll email it to you also. Ron

email (option): ronpier@talk21.com

Thangs Ron, But still not surre what body assembly Is it the 276/014R? I have heard it should be the 276C/B1?
I have a 276/014R, byt when mounted the float chamber has to be on the outside. I thought it should be on the indside.

Bo

email (option): bo.orloff@gmail.com

Here two pages from the 1939 BSA parts book, motorcycles for the home and export market had different carburettors.

email (option): ahum@quicknet.nl

Well it seems at that time they were changing from the 76 range to the 276 range. Everything points to the 276/014R. Why can't the float fit either side? Perhaps Henk or Leon can answer.
I think the change was to do with air fiters being fitted. Theres no point fitting a filter on a 76 carb. So they started with the overseas models. Ron

email (option): ronpier@talk21.com

If you use the float chamber on the inside, rain can't get it. Makes sense doesn't it?

email (option): ahum@quicknet.nl

Without checking, I seem to recall a photo of a pre-war WD M20 (K M20) in my book that shows the carburetter float chamber fitted on the inside...?

One other thing to consider is that some pre-war and early wartime WD bikes were also fitted with top-feed float chambers....Royal Enfield and Ariel military models spring to mind, and the relevant parts lists reflect this.....did this occur with the M20 too...?

It is also worth remembering that many Amal carburreters fitted to WD bikes employed the same type 76/276 body, the various markings found on the bodies generally referring to the complete caburetter assembly to assist with supply and fitting to particular models.....if you are not too concerned about minute detail, any body will do providing that it is fitted with the correct internals as per specification......

Steve doesn't the 76 range have the extra air intake holes at the lower end of the body? Ron

email (option): ronpier@talk21.com

Correct Ron, so the air enters from a different area to the bellmouth....the 76 type carb therefore has a different jet block fitted incorporating similarly-positioned holes.......

It is thought that the WD specified the 276 to prevent dust and crap entering the carb from anything other than the bellmouth, important if an air cleaner was also fitted.....

Another theory is that the change from brass to Mazak alloy for the carb body meant that the latter type 76 carb was potentially more vulnerable to body fracture in light of the 4 holes around the base....

Thangs evry one.
looks like it has to be the 276/140R then, and locky me i have one on the shelf
Byt the float chamber can not be on the inside as shown on in this pictur.
http://www.wdbsa.nl/civilian/1939a.jpg
Are there difrent chambers??
Would like to have it very original, as it still is in it´s first paint.
Regards Bo

email (option): bo.orloff@gmail.com

The Amal component specification numbering system doesn't seem to follow any sort of logic and during the war years they changed to a system of numbering the complete carbs rather than just the components so identical bodies or float chambers can have different numbers.

I suspect that for 1939, you should still have a float chamber with a chromed brass cover. For some reason, the die-cast mazac cover seems to have been introduced later than the chamber itself.

The first use of the 276 type appears to have been on Nortons supplied to the India Office - effectively the pre-war proving ground for military motorcycles. Nortons retained the early type of 276 when the 276R was introduced on other makes.

I have a suspicion that the Type 76 is probably a better breathing carb (otherwise why did AMC reintroduce it ?) Nortons used it post-war as well but only on the twin, not the singles.

What is it that doesn't fit on your present float chamber ? It should still be a bottom feed but appears to have a longer arm to clear the dynamo body. There are at least three lengths of arm but the original for your bike will be stamped 264 078 as detailed in the list above.

The bowl body number would be 64/078 no 2 in front of it.They were normally marked 1B for the short arm with a horizontal drill hole on the brass 1/4 BSP thread under the bowl or a long arm bowl body was marked 1E and did not have the horizontal drill hole under neath.
John

its a swine to tickle the carb with the float chamber on the inside even worst with gloves on

Ok, mine must be one with the short arm as it hits the dynamo. Where is the number stamped on the float champer?
You do rember that mine M20 is a civilian model!!!
It is nice to hear from people who know M20.
Thangs

email (option): bo.orloff@gmail.com