It's impossible for fuel to come out the carb when fueling if the carb is working right..the inlet needle takes at least 10 lbs to unseat, there's no fuel pump that puts out that much pressure...Take the steel cover off the carb...the inlet needle lever should be flush with the casting next to it...the lever has a little fork in the end..If the center metal part of the diaphragm is not hooked into this fork the needle will not close and fuel WILL go through the carb when the tank is filled...otherwise..NO WAY....