This invention relates to starting devices for four-stroke cycle engines..
The invention comprises the provision of a cut-off or throttling member in the pipe through which the atmospheric air is drawn by the suction of the engine. This throttling device is connected to the starting valve mechanism in such a manner that on starting the engine the throttle is closed, and thereby, during that part of the motion of the piston at which atmospheric air is normally drawn in, no air, or at least only rarefied air, is drawn in, and on the return stroke of the piston only the rarefied air has to be compressed, whilst when the starting valve is arranged for the supply of fuel the throttling valve is opened.