When I was 40 years younger and weighed 140 pounds I remember checking on my Motron and had gone 100 miles on a tank and had not ran out of gas.
At 180 pounds with a stock bike and mild porting, I tan out of gas at about 65 miles.
This is assuming that the tank holds a gallon.
I used unleaded gas and any old 2 cycle oil back then, and this was last fall with ethanol free gas and Red Line 2 cycle oil with different clutch springs.