AJS & Matchless Owners Club

I know very little about carbs but I recently fitted a Concentric Mk1 to my 18S and that leaked from tickler and jet in Venturi - problem was the float bowl gasket which trapped float pivots, holding float open. Cut away offending parts of gasket, and hey presto! no more leaks. Don't know if this is relevant to your issue, but may help. Andy

clanger9 wrote: the little bump on the cover that tells you where the fuel level is supposed to be will be in slightly the wrong place

I have heard this many times before, but how can you see if the fuel level is where the bump is? Remove the banjo and look inside?

Another thing to watch out for with a leak on a Monobloc is make sure there is no fibre washer between the carb body and the needle seating, a washer here stops the needle seating properly.

To view the petrol level in the float chamber remove the pilot jet hexagon cap and fit a clear length of pipe to the pilot jet, hold the pipe along side the tit on the chamber cover when the petrol is switched on the petrol should be level with said tit without tickling.

Also it can be checked by replacing the float chamber cover and replacing it with clear Perspex cover with a line scribed at the same height as tit on original cover.

I have used both methods without problems.

Colin

Thanks Colin, I'll give the clear pipe a go.

Peter

If it's the wrong height you can get a fuel level adjusting kit........

http://amalcarb.co.uk/washer-kit-for-se ... ttors.html

Peter Morris wrote:Another thing to watch out for with a leak on a Monobloc is make sure there is no fibre washer between the carb body and the needle seating, a washer here stops the needle seating properly.

Hi Peter, this is where life gets complicated as originally there was no washer fitted nor should the be, however the latest generation/newly manfactured monobloc do have a washer there and one is supplied in the Amal gasket sets.

Duncan wrote:

Peter Morris wrote:Another thing to watch out for with a leak on a Monobloc is make sure there is no fibre washer between the carb body and the needle seating, a washer here stops the needle seating properly.

Hi Peter, this is where life gets complicated as originally there was no washer fitted nor should the be, however the latest generation/newly manfactured monobloc do have a washer there and one is supplied in the Amal gasket sets.