Oil & Fuel Deere Mower D-140 won't start

[ZMartin]

2013 John Deere D-140 mower, under 60 hours of operation, will not start. Followed the troubleshooting guide but to no avail. Changed the plugs, gas & air filter, installed a new battery and changed the fuse and NADA! Wondering if it could be a fuel issue. Have been using 87 octane for the past year with no issues. Any suggestions are very welcomed!