Spraying starter fluid into a 2 cycle engine will do irreversible damage. Your essentially washing the lubrication from the cylinders with it. Sounds like the needle valve is stuck closed or the low speed jet is clogged. Get a carb kit, and a gallon of B-12 Chemtool if you haven't already. Kit will come with new needle, needle and gaskets. Fully disassemble, including jets and remove all gaskets/float before soaking.