Abstract: Inversion-protection of an outboard marine engine is achieved by fitting inside the engine casing watertight boxes to enclose the water-sensitive electrical components, i.e. the engine starter solenoid and the power pack. The starter motor spindle is provided with a shaft seal and the engine exhaust is fitted with an exhaust pipe in the form of a vertical hairpin or U-tube. The engine air intake box has fitted inside it a horizontally sliding valve that is automatically closed by a vertically-sliding weighted wedge engaging the valve rod.

Abstract: An air intake water-tighting device is provided for a marine outboard motor for closing the intake automatically to prevent the ingress of water in the event of a capsize of the craft to which the outboard motor is fitted. The device consists of a valve casing adapted to fit over the engine air intake, a ported sleeve fixed in the valve casing, a rotary ported barrel fitted to swivel inside the sleeve, and an air inlet trunk outside the valve and fixed to one end of the barrel which air inlet trunk is so weighted that it turns the barrel through approximately 180.degree. in the sleeve in the event of a capsize and thereby moves the ports in the sleeve and barrel angularly out of register.