Abstract: The present invention provides a crankcase compression type two-cycle engine which has a comparatively simple construction, is capable of operating at a low fuel consumption and discharges an exhaust gas having a comparatively low hydrocarbon concentration. The engine comprises a crankcase, a piston, a cylinder joined to the crankcase and provided in its lower part with an exhaust port which is opened and closed by the piston, a cylinder head attached to the upper end of the cylinder, and forming a combustion chamber together with the cylinder and the piston. A poppet scavenging valve is provided in the upper part of the cylinder so as to be opened to the combustion chamber side. A diaphragm actuator operates the poppet scavenging valve using the pressure within the crankcase. The diaphragm actuator is provided with a diaphragm that receives the pressure within the crankcase on one side thereof and receives the pressure of a spring on the other side thereof.

Abstract: A device for controlling a pneumatic injection of a carbureted mixture into a combustion chamber of a two stroke internal combustion engine, with the device including a compressed gas supply pipe adapted to be communicated with the combustion chamber of a cylinder by an intermittent sealing element, and a fuel metering device opening into the compressed gas supply pipe. A selective sealing element is arranged in the compressed gas supply pipe upstream from the intermittent sealing element and from the fuel injection device for controlling all carbureted mixture conveyed into the compressed gas supply pipe and used for pneumatic injection according to operating conditions of the internal combustion engine.

Abstract: A two cycle engine having piston controlled inlet and exhaust ports is provided with a secondary one-way valved air fuel mixture passage to the combustion chamber adjacent the spark plug.