I am retoring my second WD M20 1941. The carby that was with it has the numbers 76AT/1EF (i am thinking it should be 276AT/1EF). Its different then the my other 1942 WD M20 which is 276DB/IA. As well, the caby's look different. The 76AT/1EF has a shorter throat (the part that attaches to the barrel)and has holes around the carby body and had a 120 jet fitted. The motor had a burnt out exhurst value sleve. I've been told that you must run a 170 jet in an M20 anything lower you can risk burning out values.

My question to the forum is: Will the 76AT/1EF (with 170 jet) carby be OK to run on the bike?

Bryce, the 76 carb should work just as well as a 276, with the correct 170 main jet and 6/4 slide. The 76 carbs were mostly being replaced with the 276 around 1940, especially for bikes destined for overseas, with a need for an air filter. No point fitting a filter to a 76 which is drawing air through those four holes.

Ron

email (option): ronpier@talk21.com

Thanks Ron, i can breath a little easier.

Hi Bryce,
Yes, it should work with the correct jetting.
The original carb was an Amal 276C/1B.

Ron,
I think that there is some benefit to putting an air filter to the 76.
As far as I remember, it drew air through the bottom hols only for idle.
For anything above idle it used the regular rear intake.

Cheers,
Noam.

email (option): noam10@gmail.com

A 76AT/1EF was fitted to 1954 AJS/Matchless. For some reason they stuck with the carb body with the four holes around the base which most bike manufacturers did away with during the war so all the air could be filtered on direction of the War Office. It is a one inch carby so will be fine as Ron has suggested, just check that the float bowl is marked 1A or IB or 1C to denote no angle on the bowl as an 1EF bowl is on a seven degree angle. However it is common to find a carb that has a different bowl on it.
John

I recently bought good a 276/014R with a 6/3 slide. The 276c/1b I have fitted to mine is a little worn and is running the bike a little lean. I was told the 14R would be ok to run as a replacement. Is this correct ?
Rich

email (option): richardpurkiss@hotmail.com

M20's would run on an oily rag. Just persist with what you have.