Have you tried twisting the carb on the stub. Just a little to alter the float height.Comet with brass/bronze carb body which appears to be all original.. Same problem. Not cured by all (three) new fibre washers on the carburettor., including the large on directly i contact with the carburettor body.
Petrol weeps from the very top of the large flange which screws into the bottom of the carburettor body. I gather that the thinking is that the float chamber level could be too high. Fitted a new tap because the tap itself was leaking, so that possible reason is eliminated..
Any updates on a cure please.