Hello! So lately my bike has been getting maybe 25-35 miles to the gallon, usually making me stop to refill at about 65 or 80 miles. I don't see any noticeable leaks, and the bike has smoke on startup that goes away pretty quickly. Also, when hot, if I turn her off she'll refuse to start up again until a very loud backfire occurs, then she'll start up a few turns after. Any ideas gentlemen?