ExMark 52-in Lazer HP, 52-inch deck with Kowalski FH680V 23 HP. Mower runs fine for 10+ minutes then the engine stops. Seems like fuel starvation, fuel tank full. Initially the engine restarted right back up and ran for a few more minutes. Now after the initial engine shutdown it will only restart for a very short time. Changed the fuel pump. Fuel from tank flows good to the fuel filter but the see-through fuel filter is not full of fuel.