Bad fuel economy

At that fuel mileage, the engine should barely be running and with almost no power. You will leave a huge cloud of black smoke from the tail pipe. Check the choke to be sure it is opening fully. If it is not, check the choke pull-off, then the choke spring heater system.

A better suspect, especially if the engine is running properly, is a dragging brake. Stop on a slight incline, push in the clutch, then see if the vehicle creeps downhill on its own. If it does not, we will need to look at the brakes.