The GALI air starters are devices generally installed as auxiliary units of thermal motors or turbines, for their start-up. These starters are based on the principle of two geared rotors which are turned through the action of air pressure. This movement is subjected to the appropriate reduction to obtain a determined torque on the output shaft. To this shaft the appropriate pinion is fitted and the movement thereof pulls the motor it is desired to start. This pulling action is achieved by meshing the pinion of the starter with a crown wheel usually fitted on the flywheel of the motor. The starters have internal mechanisms to achieve the meshing and avoid their start-up until it has been carried out successfully. They are also provided with a device that avoids reengagement.