A device manufacturing method is disclosed. As one example, the control method includes transferring one type of fuel from one fuel tank to a second fuel tank holding another type of fuel and adjusting an engine operating parameter based on the blended fuel mixture by selective operation of a first and second fuel pump. The second frame includes a front beam connected to the first frame by a center pivot so as to allow side to side pivotal movement of the second frame and two force transmitting members spaced outwardly of the pivot.