A marine engine fuel system provides a low pressure lift pump to draw fuel from a fuel tank and cause the fuel to flow into a reservoir and a high pressure fuel pump which draws fuel from the reservoir and provides it to a fuel rail. An inlet conduit of the high pressure fuel pump is provided with a primary and a secondary opening. The secondary opening can be an orifice formed through a wall of the inlet conduit. The secondary opening is positioned, relative to the primary opening, at a location which assists in controlling the fuel level within the reservoir and the quantity of gaseous fuel contained within an ullage above the liquid pool of fuel.