When I first got my bike (an old vf series) I thought I was getting horrible mileage ,just based on 120 miles to a tank turns out I was only using around 3 gallons or so of the 5.X gallon capacity. The orange spot on the gauge where I believed I would need reserve was really 1/8 of a tank so I still had over a gallon before hitting the 1.X gallon reserve. Started paying attention to how much I was putting back in and realized also that my after gauge would read just to full I could get nearly another gallon in it (indicated as above full on the gauge). Anyhow jetted a little bit rich (just enough to get rid of the typical cold natured ness of a Honda, avoid overtaking the cooling system, and run notably better when the air is cool and dense) I get around 35-40 mpg. Much better than my initial impression of around 25mpg. It's always good to go through a new to you bike with a fine toothed comb and fix any problems/ patch up any shoddy repairs before they cause any real damage. Although unless it's loading up with carbon or running rough, i wouldn't be too concerned until at least I properly topped the tank, reset the trip meter ,run out the tank and topped up to the same level again to get a decent bead on mileage.