Abstract: Systems and methods are for controlling combustion in a marine drive. The systems can include a computer processor device and a computer memory device comprising instructions. The instructions are executable by the computer processor device to control a timing of spark in an engine, by determine a base spark advance based on a predetermined nominal humidity, a load of the engine, and a revolutions per minute (RPM) value of the engine. Additionally, the instructions are executable to determine a humidity offset value based on a specific humidity of intake air to the engine and the load of the engine. Further, the instructions are executable to determine a controlling spark advance value based on the base spark advance and the humidity offset value. Additionally, the instructions are executable to send the controlling spark advance value to an ignition system of the engine.

Abstract: A cooling system is for cooling a marine engine having an engine block and a cylinder head, and a supercharger configured to provide charge air for combustion in the marine engine. The cooling system has a charge air cooler configured to cool the charge air prior to combustion in the marine engine. The cooling system is configured to circulate cooling water from a body of water in which the marine engine is operating to the marine engine and then back to the body of water. The cooling system is further configured to convey the cooling water in parallel to the marine engine and the charge air cooler. A sprayer is configured to spray the cooling water into exhaust gas discharged from the marine engine. The cooling system is configured to convey the cooling water in series to the charge air cooler and then to the sprayer.