Well it obviously is starving for fuel. You need to do more checking or bring the mower here. Is the gas tank cap vent open, is the Intake manifold loose, gaskets leaking, does fuel flow freely when the gas line is disconnected from the carb (assuming it is gravity feed) IF not gravity feed, is the fuel pump working?

Just for starters. Here again, there are more than one 12.5 hp B&S engines so the engine model number is necessary.

Walt Conner

Have you tried replacing the needle? How about the fuel filter (worth a shot).

hey guys thanks for the help ok it has a inline filter i took the line loose from the carb opened the shutoff valve and gas flows threw the line and i empty the carbbowel out and turn the gas back on and it filles up with gas just dont go in the chamber so to speak to fire now i take the neddle and float out and choke have the carb and guess what it runs just fine i bought the neddle and float last year before i put the mower up for winter When it stops raining ill try to get the serial number i put a new plug and filter also Ill let yal know asap on the number Thanks so much