I have '54 ES2 which acording to Haycroft should be fitted with an Amal 276AU. It is actually fitted with an Amal Monobloc wiht the numbers 376/253 stamped on it. So, some questions:
What are the correct main jet size, the throttle valve cutaway and the needle position?
What does 253 mean on the carb body?
Presumably this carb will work just as well on the '54 model as the '55?
Many thanks for any info.
George
Hi just click on the size…
Hi just click on the size of carb you have it then gives the settings hope it helps.
Thanks Barry - I'd been t…
Thanks Barry - I'd been there and it is very useful. The problem I have is that it is the wrong carb for the bike/year (it's meant for a 350 BSA not a 500 Norton). I'm trying to ascertain if I can re-jet it and fit a dffernent throttle slide and thus make it correct (ish) for my bike. Thanks for your input.
George
if it's the same bore I'…
if it's the same bore I'd have thought you'd have a good chance of getting it to work. I'd give Surrey Cycles a ring they have all the application books, but if I were you and I was going to be riding it l'd think about buying a new one?
dan
Thanks Dan. Do you have an…
Thanks Dan. Do you have any contact details for Surrey Cycles?
I have ridden it and it goes quite well. A bit tricky to start (wrong pilot jet?) and gives the impression of more noise than poke when accelerating. This could be the 190 main jet rather than a 270. I just need to know if changing the jets will be an acceptable solution. A new carb will be a lot of pennies!
George
It's surreycycles.com …
It's surreycycles.com £140 might seem a lot but it soon adds up if you have to buy a slide, needle and a few jets!
Dan
Previously George Phillips…
Previously George Phillips wrote:
I have '54 ES2 which acording to Haycroft should be fitted with an Amal 276AU. It is actually fitted with an Amal Monobloc wiht the numbers 376/253 stamped on it.
Once Amal had a build specification for a particular bike, they gave it a number - such as 376/253. If you change one component, that results in a different build specification, and requires a different number. If another bike proves to need exactly the same build, it gets a carb with the same number.
Once a bike enters service, it may get a larger main jet, or a smaller one if an air filter is fitted. It's no longer to build spec. Build spec is not sacred!
Any Monobloc of the right bore is suitable, assuming that the body is in sound condition. Your bike got a Monobloc for 1955. The build spec for that bike is a good guide to the correct spec for your machine.
Previously George Phillips…
Previously George Phillips wrote:
I have '54 ES2 which acording to Haycroft should be fitted with an Amal 276AU. It is actually fitted with an Amal Monobloc wiht the numbers 376/253 stamped on it. So, some questions:
What are the correct main jet size, the throttle valve cutaway and the needle position?
What does 253 mean on the carb body?
Presumably this carb will work just as well on the '54 model as the '55?
Many thanks for any info.
George
The jets and settings for a 1960 ES2 are:
376/249 Norton 500cc 1960; ES2 (Export) 1 1/16" 30 3.5 270 0.113
The columns are:
| choke size | pilot jet | slide | main jet | needle jet| needle position
Your carb is;
376/253 BSA 350cc 1960-62 B40 1 1/16" 20 3 190 0.11 3so you need a main jet, slide and pilot jet at least to convert it to 1960 ES2 spec which should be a good starting point.
EDIT: Just found this higher up the page:
376/017 Norton 500cc 1955-63; ES2, 19R 1 1/16" 30 4 270 0.11 3Hi George, with the slide…
Hi George, with the slide cutaway, the #3 you havewill give a slightly richer mixture than the #3-1/2 or #4. The numbers are the height of the cutaway in 1/16" increments, so if you are half handy with a fine file, you can carefullyincrease the cutaway height to 3-1/2 16ths" (7/32") or a bit moreto a 1/4" (4x1/16ths"). Saves unnecessarily buying a new slide.
Paul
Previously Jonathan Soons…
Previously Jonathan Soons wrote:
Previously George Phillips wrote:
I have '54 ES2 which acording to Haycroft should be fitted with an Amal 276AU. It is actually fitted with an Amal Monobloc wiht the numbers 376/253 stamped on it. So, some questions:
What are the correct main jet size, the throttle valve cutaway and the needle position?
What does 253 mean on the carb body?
Presumably this carb will work just as well on the '54 model as the '55?
Many thanks for any info.
George
The jets and settings for a 1960 ES2 are:
376/249 Norton 500cc 1960; ES2 (Export) 1 1/16" 30 3.5 270 0.113
The columns are:
| choke size | pilot jet | slide | main jet | needle jet| needle position
Your carb is;
376/253 BSA 350cc 1960-62 B40 1 1/16" 20 3 190 0.11 3so you need a main jet, slide and pilot jet at least to convert it to 1960 ES2 spec which should be a good starting point.
EDIT: Just found this higher up the page:
376/017 Norton 500cc 1955-63; ES2, 19R 1 1/16" 30 4 270 0.11 3
Thanks to both Paul and Jonathan. I've been on to that site for the carb info. Very useful. I'm beginning to see which way I've got to go with this. Another complication is that the compression ratio changed from '54 to '55 si I'd better check that first. It will give an idea of whether the carb should be set for a '54 or '55 bike. I've taken on board the cutaway issue.
George
Previously George Phillips…
Previously George Phillips wrote:
I have '54 ES2 which acording to Haycroft should be fitted with an Amal 276AU. It is actually fitted with an Amal Monobloc wiht the numbers 376/253 stamped on it. So, some questions:
What are the correct main jet size, the throttle valve cutaway and the needle position?
What does 253 mean on the carb body?
Presumably this carb will work just as well on the '54 model as the '55?
Many thanks for any info.
George
Hello 1954 models Have a Pre Mono bloc Carburetor . the Mono Bloc did not come out until 1955 . Have a big Amal Manuel you not seen the likes of its over 2 inch thick and packed with information yours Anna J
Previously anna jeannette…
Previously anna jeannette Dixon wrote:
Previously George Phillips wrote:Hello 1954 models Have a Pre Mono bloc Carburetor . the Mono Bloc did not come out until 1955 . Have a big Amal Manuel you not seen the likes of its over 2 inch thick and packed with information yours Anna JI have '54 ES2 which acording to Haycroft should be fitted with an Amal 276AU. It is actually fitted with an Amal Monobloc wiht the numbers 376/253 stamped on it. So, some questions:
What are the correct main jet size, the throttle valve cutaway and the needle position?
What does 253 mean on the carb body?
Presumably this carb will work just as well on the '54 model as the '55?
Many thanks for any info.
George
Thanks for that Anna. Sounds like a useful tome!
Just checked the engine/farme numbers on the web and the bike is indeed '55 so the monobloc is corect! It's just that the second set of numbers (253) which I take to be the factory setting, was for a 350 BSA so I'll have to have a look at the jets etc and see if they are what they are supposed to be. George
Done a bit more research on this and it seems thta the main diffreence between the two carbs (apart from the obvious) are:
376/17 30 pilot; 4 cutaway; 270 main jet
Monobloc 20 pilot; 3 cutaway; 190 main jet.
Presumable if I change the pilot jet, the throttle slide and the main jet I should have the correct (ish) carb for the bike?
Any views?
George