This paper deals with a new method allowing recent model-free control technique to deal with underactuated mechanical systems for stable limit cycles generation. A model-free controller is designed in order to track some parametrized reference trajectories. A second model-free controller is then designed using trajectories' parameters as control inputs in order to stabilize the internal dynamics. The proposed method is applied to a real underactuated mechanical system: the inertia wheel inverted pendulum. Numerical simulations as well as real-time experiments are presented showing the e ectiveness of the proposed control method and its robustness toward external disturbances.