I have a Kubota B1750 and after mowing for about35 minutes, it started acting like it was running out of fuel. After running roughly for about 30 seconds, it died. Let it set for a few minutes and started it up and it ran for another 10 minutes before it started running rough again. Took the fuel filter out and cleaned it (it was pretty bad),put it back in, bled it and mowed for another 30 minutes and it started running rough again and eventually died again. Anybody know what might be the problem?