One thing I learnt while on my carby goings on

When doing a rebuild , it is a very worthwhile thing, to remove the brass emulsion tube and clean it, it has tiny holes in it that do the air/petrol mixing, , the holes must be clear , this is vital if the motor is to run sweetly .

The brass tube is inside the alloy tower , the tower has the air bleed jet screwed on top , The tower sits on a webbing casting within the main venturi .

Getting the tower off its base can be tricky - it sits on a brass sleeve that protrudes about 1/4" above the casting . I don't think it is meant to be a serviceable item, but after 60 years of use, there is likely to be crud in the tube .

I applied gentle heat to the base of the tower, just enough , too much and the delicate tower will be cactus . After heating, I grabbed the tower with some small multi grips , and gently coaxed it off the base .

If your tower does break, dont worry, It would be possible to machine up some new towers from brass .... or some other suitable material . The weakest part of the tower is where the jet screws in, it is very thin there .

Mike