I remember when I was doing my oil change about a year ago, using genuine suzuki synthetic oil, I filled it right to the upper mark in the sight glass. Yesterday I went to check the oil, after the bike sat overnight, and the oil is up to almost the top of the sight glass, maybe a millimeter lower. Where's did the extra oil come from?  

My gas mileage has been terrible in fact, I need to test it, but I think I get like 20-25mpg. But I do like to keep the bike in the lowest gear and rev it out. Need to do what you said with smelling the oil, gas dilution is a serious issue.