Just today I had the same exact problem. I took the fuel line off of the fuel pump and pressurized the gas tank with compressed air and nothing came out. Now I removed the fuel filter and pressurized the tank once again. Nothing came out again indicating clogged or collapsed fuel line. Replaced the fuel line and filter. Unit started and ran but surges. Removed carb and cleaned with carb cleaner. Removed main jet ensuring that it was very clean. Put carb back together and reinstalled. Fired right up and runs as good as new.