Abstract: A cooling system for a heat producing system includes a heat exchanger in fluid communication with the heat producing system. The heat exchanger is configured to receive a temperature control fluid therethrough. A first fan is operable in a first rotational direction to move air through the heat exchanger in a first direction. A second fan is disposed radially adjacent to the first fan, and is operable in a second rotational direction opposite the first rotational direction to move air through the heat exchanger in the first direction. A control system, including at least one controller, is provided for controlling operation of the fans.

Abstract: A method is provided for controlling the operation of the alternator in such a way that during certain conditions, such as rapid acceleration of a marine vessel in combination with a trimming maneuver, the alternator of the marine propulsion system is deactivated so that it does not provide a mechanical load on the engine during the accelerating maneuvers. This allows the engine to provide more power to the propeller and achieve the desired operating speed commanded by the operator of a marine vessel.

Abstract: A method for controlling the electrical system of a marine vessel comprises the steps of measuring a battery potential, comparing the battery potential to a threshold voltage magnitude, and then disconnecting one or more of a plurality of electrical power consuming devices when the voltage potential is less than the threshold voltage magnitude. This is done to avoid the deleterious condition wherein an engine of the marine vessel is operating at idle speed and attempting to charge the battery while a plurality of electrical power consuming devices are operating and drawing sufficient current from the alternator to prevent the proper charging of the battery. In these circumstances, the battery potential can actually be depleted as the battery attempts to provide the additional required electrical current for the loads.

Abstract: An engine control system digitally stores corresponding values of timing angles and engine speeds and selects the timing angles based on the operating speed of the engine. In the engine speed range near idle speed, the timing angle is set to a pre-selected angle after top dead center (ATDC) and the relationship between engine speed and timing angle calls for the timing angle to be advanced from the pre-selected angle after top dead center (ATDC) to successively advancing angles which subsequently increase angles before top dead center (BTDC) as the engine increases in speed. In one application, a timing angle of 10 degrees after top dead center (ATDC) is selected for a engine idle speed of approximately 800 RPM. This relationship, which is controlled by the engine control unit, avoids stalling the engine when an operator suddenly decreases the engine speed.