That Elto has two fuel filters. One in the tank (that the fuel line fastens to) and one in the large hex plug in the bottom of the carburetor. If either is dirty, it would restrict the amount of fuel getting to the carburetor. It could get enough to start and idle, but lean out at higher throttle settings. If you forget to open the air vent on the gas cap, or if the vent gets plugged up, it will develop negative pressure in the tank, which will keep fuel from flowing into the carburetor. If you run with the lower motor covers removed, you will see the float pin drop if it is not getting enough fuel. . . . 🙂
