You have a problem that I deal with everyday when owning tractors that sit for any period of time. More than likely the fuel bowl orfices are clogged, or the needle valve is stuck in the carburetor.
I usually just take the fuel bowl off and stick the power washer inside the filler neck and turn up the heat and flush it out for about a half hour then totally take the fuel bowl apart and clean it with a pick and an air gun. Some times I even use the sand blaster to clean the fuel bowl housing as thats how bad it can get. Many times I have to just give up and put a new gas boul valve on for about $28,00 and that will fix the problem.
P.S. After power washing the tank, I blow it out good with an air hose then stick a heat gun or hair drier in the filler neck for about 20 minutes to make sure it is all dried out before putting gas back in.
Once you get gas to flow through the bowl and line hook it to the carburetor again and take the drain valve out of the bottom of the carburetor and see if you got gas to flow through the carburetor. Many times more than not you will most likely have to take the carburetor apart and clean all the orfices and jets with a torch cleaner wire then put it all back together with a new gasket and it should start up and run fine.
Hope this helps,