2005 Arctic Cat 500 4x4 Fuel leaking from bowl drain (drain screw is tight ,does drain when loosed ,stops when tightened) Fuel only leaks when engine is running, stops when engine is turned off. If I place my finger on carb to block off fuel the engine will stall. Thanks for all your help.....

 

You need to check the float level. If it is too high it will slop over into the drain thru the vent at the top of the bowl.