I have a Craftsman 18.5hp with a B&S OHV engine. It started sputtering today. Now it will run for about 30 seconds and shut off. I've replaced fuel, fuel filter, eliminated the soliniod on the carb bowl with no luck. It does have a black round device on the side of the engine that that the fuel line hooks ot to on one side and back the other, also a vacuum line hooked up to it also. Any ideas what ti try?

Hi,
Your describing the fuel pump. Try disconnecting the line going to the carb to see if you get a strong pulse of fuel when the engine spins over.
Peace,
Clarke