I have new fuel taps which do not leak but carb leaks as soon as fuel is turned on. Still hopefully this will be cured once I have the Concentric carb fitted.Any side bowl type 276 or 289 carb will drip fuel if the machine is sat on it's side stand, and also if the fuel taps are leaking internally...........Disconnect the fuel pipe connection and leave a small container under the tap overnight and you will find a lot leak internally...........This is the primary cause of leaks from these carby's............No amount of replacement gaskets and sealants will stop it.