I have a G2160 Diesel lawn tractor. This spring I uncovered my G2160 charged the battery and it started right up. Checked all fluids and kicked the tires. Cut the lawn (about 3 acres). The next day it was more difficult to start, plenty of crank and after about the 5th or 6th try it started. It ran fine, the next day it was even more difficult to start, once I got it started it ran fine. Yesterday I had even more difficulty starting, had to recharge the battery but once started it ran fine. Even though I changed the fuel filter before winter storage but changed the filter (new) it still had a difficult time starting. Today it will not start at all, plenty of crank. Deat switch is fine and fuse is fine. Anyone with an idea why this is happening?