sjessen is right on. A full tank should get you 2 hours. While using it myself I did become quite confused when it ran out of gas. The ZTR was going and the blades were on. With all of that noise and and regular vibration I couldn't even tell when the blower died. I thought something broke because the leaves were no long moving. I turned off the blades and started reviewing the blower. I got a good laugh at myself when I realized the engine was out of gas.
Drew Coates, AKA Mr. Force