Just got my AR and its brill except on small niggle.

If I leave the fuel tap on it continually drips fuel from the breather pipe. Even with the engine running as soon as I stop a small puddle starts to form.

Anyone know what's wrong with it? Or is this normal??

Float is sticking. Try giving the bowl a tap with the base of a screwdriver or something to shock it shut. Failing that a carb strip and clean will be needed.