Well if you have a 1/4 of a tank of gas, take one of the pipe plugs out of the front wheel hubs and remove the sediment bowl assembly from the tank. Takes an 18 MM wrench for most of them. Let a little gas flush the dirt if any out of the tank and then screw the pipe plug you took out of the hub in the tank and check the assemly. I have seen bugs in the fill tube of the sediment bowl as well. When you go to the parts store to get some fittings to do your pressure check and a 2000 PSI gauge also get a foot of clear plastic tubing and a fitting  that will attach the tubing to a 1/8 inch male pipe thread as well. Take the drain plug out of the carburetor  and attach the hose and fitting to that port. Make sure you tie the hose up in the vertical position. Then when the tractor is running you can check if the float level in the carburetor is correct and if the fuel leaves the tube you will know you have other restrictions in the inlet side of the fuel system which can include a sticking needle &amp; seat. Confused?