Weed wacker bolen weed wacker won't start. it will start if you fill carb with fuel

Check the fuek lines for hole and leaks, check the fuel filter and clean if necessary. remove the carbuerator and inspect the gasket; it should be soft and flexible, if it seems hard or brittle replace it. clean the carb with carb cleaner sray (available at any local auto parts store) and compressed air. make sure you get inside the small fuel rail holes. if that doesn't work have the carb repaired at a service center or replaced.