Combustion engines

This invention relates generally to combustion engines, and more particularly to increasing the safety and performance of engines used for marine applications. Engine safety features include an intake silencer defining an internal volume sized to help attenuate air pressure fluctuations generated within the carburetor and engine and transmitted back through the entering combustion air, and also functions as a flame arrester. An internal drip well collects fuel droplets to be siphoned through a hose back to the engine intake system for combustion. The carburetor bowl operates to allow gas and relatively safe vapor out of the carburetor during venting, but disallows liquid fuel from flowing out of the carburetor through the vent. A ball check valve drain disposed in an air intake enables suction of liquid fuel from the silencer into the intake manifold but inhibits suction of air. These features are useful modifications of commercially available engines to improve their suitability for marine applications such as on board electrical power generation, for example.