I have a 19 horse briggs 407777-0124-e1 should gas come out freely from the carb if I put the gas tank in the air .it has a fuel pump.okay heres whats going on.i bought a troy bilt 42 inch with this motor and the guy had to put gas down the carb to start it.after about three times it stayed running but only with the choke out about a inch.wasnt running good but I did get it in the truck.i figured dirt got in the carb etc.i emptied the tank put new filter on it and cleaned carb three times.when I put a steady stream of carb cleaner in the carb it runs fine telling me dirty jets or float.ive never owed any mower with a fuel pump or a carb like this so im confused.i hope its a fuel pump.what do you guys think?