Just so you dont do what I did.... Is the valve on the gas filter turned ON? Yea, being the dummy I can sometimes be, I shut that valve off, because I smelled gas. The tractor sat for several weeks. I think I spent about 3 days trying to figure out why it would not start, before I remembered shutting off that valve... !!!
(getting old sucks) :)
I have since replaced the gas filter gasket so I dont smell gas, and thus dont need to shut off the gas valve.