I'm pretty sure I have an air leak on somewhere on my inlet manifold which is preventing me from setting the carb up properly. When the engine is cold and the choke is full on the engine runs sweet and healthy. But once the choke has heated up and the inlet flap is fully open the engine starts to cough and splutter and refuses to idle without cutting out. No amount of adjustment fixes this. However, if I disconnect the choke completely so that the flap remains partially closed at all times the problem is solved and the engine runs sweet and healthy with a fast idle. I'm assuming this is caused by an air leak and the carb flap remaining partially closed is compensating for the extra air being drawn into the manifold from somewhere else. Does this make sense - am I on the right track?