Riding Mower Won't Turn Over?

I have a 3 year old Craftsman 42" riding mower with a 420CC engine. I was 30 minutes into my lawn and it just bogged down as if it ran out of gas. There's plenty of gas in the tank. I changed my oil and filter earlier this season, but not the fuel filter. When I try to restart the engine, it just spins and spins and then back fires, but does not start. Could it be the fuel filter or something else? Any feedback would be appreciated.