right now on my 70cc I've got a one quart gas tank from a lawnmower. Figured that would be fine for the short hops I make. Went out for a haircut the other day, 16 miles round trip, and didn't make it! Ran out of gas two miles from home, and I had topped it off just before leaving. So that's what, not even 60mpg? What's up with that? And I do a lot of pulling the clutch to roll down hill, and even shutting the engine off on long down grades. Bike runs fine. Checked the plug and it looks fine fine.