I HAVE THIS GRAVELY ZERO TURN, I BELIEVE ITS A 1995, HAS A KOHLER CV20, 20 HP V TWIN MOTOR, WOULD ONLY RUN ON FULL CHOKE, CLEANED CARB,AND IT RAN GREAT FOR 5 HOURS,THEN STALLED AND AGAIN WILL ONLY RAN ON CKOKE, THIS TIME I REMOVERED THE GAS TANK AND FLUSHED IT OUT, IT REALLY WASNT BAD, I THEN...