Worth the bother? Carburettor question.

[G3L1946]

Hi,

My 1947 G3L has a ‘slightly’ newer carburettor than it originally would have had which results in the float bowl not being completely vertical. The 76D/ 1J ( which should be fitted ) has a bowl angle of 15 degrees. The 76AE/1AK ( fitted ) has only a 3 degree angle. Both carburettors appear to be identical in specifications apart from the bowl angle. Is it worth replacing the parts out of the fitted float bowl into a spare 1J float bowl that I have? How critical is it that the bowl sits exactly vertical? They appear to have changed from the 76D to the 76AE in 1951 for some reason.
I’m going to remove the fuel tank over the winter to get the silver piping painted on for me so it’s an opportunity to deal with it if it’s worth it.

I belong to two clubs.
1. If it works….leave it alone ( but, I’ve not had the bike long and not really tested it much! ).
2. While I got the chance…do it!

Advice, as always, much appreciated.

Steve

[Duncan]

Steve, the change will have been when the cylinder head went from cast iron to aluminium, personally I would change the float bowl as there is a risk that the needle will be rubbing on the recess in the cap and prevent petrol flowing in or jam and flood, there is no guarantee that your fuel level is correct either.

[G3L1946]

Hi Duncan,

Thanks for reply and explanation. I’m hoping that the float, needle etc. will be compatible to put into the 1J float bowl. At this point I can’t see why not.
Regards,

Steve

[adz25]

Steve,

I had an issue on my ariel where the wrong float bowl was used, every now and then the float would stick and fuel would leak from the bowl down onto the magneto it would also cause rough running of the engine. Potential for fire risk in my case.

I swapped for the correct angle bowl and all parts were compatible.

Hope this helps

Adam

[G3L1946]

Hi Adam,

Thanks for your advice. I can see no reason why the float etc.( from the fitted bowl ) to the 1J will not be compatible. Hope I’m not proved wrong! Even if I am float kits are available.

Cheers,

Steve

[adz25]

Replacement float needles are not expensive, I opted for a new one and lapped it gently with autosol to ensure a fuel tight seal and kept the original copper float. I guess it depends how worn your needle is, which you will find out shortly!

Adam

[G3L1946]

Hi Adam,
I’m now convinced that exchanging the float bowl is the correct way to go. I’ve put an advert in ‘wanted’ for a cap, float and needle. I’ll build a complete 1/J unit up, if I can, and retain the other in its original state. Good idea to get a new needle though.
Steve