I noticed a great big discrepancy in certain 610's.... If you would please let me know your mileage, any jetting you've done or other mods, and your location/altitude. It seems that I'm getting around 100 miles from a tank, when I should be getting much more. The bike is totally stock, as far as engine mods go, air filter is clean and the bike has 3000km's on it.(1875 miles) It doesn't seem to affect the bike much whether I ride it hard or easy....still churns out the same mileage.... JD jet kit, I think is what I need.