GEBE 2 Stroke Kit Owners- How Many Miles Per Tank?

I have my new GEBE 32cc Tanaka kit running and have been testing it out in the neighborhood. I've had zero issues and it's working great. The gas tank is very small of course, but in say, 12 miles I went through 2/3 a tank. The bike is about 50lbs ready for a trip and I weigh 165. How many miles per tank can I expect and what MPG do you actually get?
Thanks

That makes sense. I calculated that 5 tanks = 1 gallon. At about 22 miles per tank, that would be 110mpg. Not a bad start considering I have been doing short trips with a tight engine.