Last week I used my new 2N for discing about an hour without issues. The engine than started sputtering / doggy and would eventually quit. The guy I bought it from said it was probably out of gas.........filled it full with gas today and it only took 5 gallons so it wasn't low on gas. It started right up and ran well for a couple of minutes. Then the engine started acting doggy and it quit. I fiddled with it. At one point it idled for 4 minutes without issue and then quit. There was a little gunk in the sediment bowl which I cleaned out. I disconnected the fuel line from the carburetor and it had good flow...............any suggestions?