AMAL 2 Jet shroud

[AusOB_Collector]

Hi all

I've been working on getting my 102 back into service with the original AMAL carb that I acquired. Everything has gone back perfectly except the shoud over the intake on the carburettor. It is not one of the choked variants but basically it is too big to screw on to the carbie.
Did seagull make different sizes of where the shroud threads on as there is at least a mil or two gap in between.

Some external help has suggested that it could have possibly never been screwed down tight and rattled around, therefore enlarging the size of the threaded part of the shroud.

Hopefully you all get my gist....

Cheers
BP

[Oyster 49]

Could it be that the shroud has been machined and rethreaded for another carb? I would suggest measuring the threads both diameter and pitch, you then will know exactly what is going on.

[Nudge]

Is it like this?


the threaded hole is 19.4mm 24TPI 55°

My newer ones seem to be the same size (ones with a choke)


The one for the 416 is
30.7mm 24TPI 55°


Have you got any way of measuring what you have got?

[headdownarseup]

Check that the thread on the carb isn't chewed up either. I've got 1 here that suffers the opposite symptoms. (very sloppy fit but using the correct inlet cowl)
Interesting that there is THAT MUCH play between the threads.
Are you certain that the cowl you're using is correct for the 46n carb?

Jon

[AusOB_Collector]

Nudge

Ye that is the same shroud/cowl I have. It could have possibly been remachined to fit another carb, I do not know.
Jon, the threads on the carb body are fine as for the water test I did I just used an anzani SS shroud and that screwed on fine.

As this is the shroud with no choke, then I am assuming it is for the 46n; how many different shrouds/cowls did seagull have for a 46n?
Centuries have the carburettor with a choke but on the AMAL variants they utilise a 46n...

Cheers
BP

[Keith.P]

Some variations of the 46n carb cowl exist, but I think that they are all the same size, with or without choke.
If I remember correctly, the seagull cowl will not fit on a SS AMAL carb, A little too big, if that's what you have, the SS cowl is adjustable, so maybe that's why it fits better, it also has its own choke, on the 40's model anyway.

[bburgess]

Hi BP,
my 102-AD, had the same defect, as you can see from the photo it was glued on when I got it, me thinks because of the fine thread it was both corroded and partly stripped.
When I put it all back together again I simply cleaned everything up and re-glued it in the correct position.
Regards .......... Bill

[Collector Inspector]

Outstanding work on that AD BB

You are now piped on board Mate.

What do you think BP....gets ya out of a problem aye.

B

[headdownarseup]

As far as my data can tell me, all the amal carb cowls with the exception of the 400 series carbs,all use the virtually the same cowl. The only real difference between all of them is the choke flap and that's it. Apart from the very early variants (and i'm talking about post war models here NOT wartime and older models) the visual differences are what is actually cast into them. e.g. early type have just SEAGULL cast into them (no choke) the second type has SEAGULL PATENT (again with no choke) there is a variant that has a choke flap with SEAGULL PATENT cast into it but this seems quite short lived and then there's the more common type ( slightly different shape to the others) that has SEAGULL DONT FLOOD EXCEPT WHEN COLD.

Pics below to confirm this

Jon