Pull the needle and seat out of the right side of the carb. There is a vertical port down into the tank bowl, you can see it in the threads before the main jet. At the bottom of it is a screen, it may be plugged. You can try using carb cleaner by snaking the supplied plastic tube down the hole and blasting it clean, or try using compressed air and a rubber tipped nozzle. If that doesn't work, the whole tank/carb unit will need to be removed for cleaning. Good luck!