I have a BX1850 that has worked fine for 2 months. I used it at a friends place to move a pile. He brought it back the next morning cleaned up and refueled. I mowed an acre, then put it away. Next morning, it starts but dies if I step on Fwd or Reverse pedal. I replaced 2 fuel filters and the air filter and followed bleeding procedures in manual (turn key to on for 30 sec, then start for 30 seconds, then turn off). Previous owner disabled the security shut off under seat...FYI. Is my fuel pump not pumping?