I have a 1998 Snapper mower, my problems started when my old fuel filter got plugged up, I went to the local snapper dealership.  The new 50 micron filters kept running out of fuel.  I checked the manual finally the book calls for a 75 micron fuel filter, the local store only sold 50 micron fuel filters.  All the new mowers have electric fuel pumps, the 50 micron filter is great, doesn't work for my gravity fed system.  Well I did order a 75 micron fuel filter off of Amazon, my fuel filter would run out of fuel when I had a half a tank, because there wasn't enough pressure in the tank to keep my gravity fed system full.  I finally ordered this 150 micron filter, no more problems.  We mowed all weekend long.  I will be ordering several more of these to keep on hand for my future needs.