Systems and methods for controlling combustion in an engine of a marine drive

A system for controlling combustion in a marine drive, the system comprising:

• a computer processor device;
• and
• a computer memory device comprising instructions that are executable by the computer processor device to control an intake airflow of an engine by:
• calculating a modified intake airflow based on a humidity airflow correction, a load of the engine and a specific humidity;
• and
• determining a throttle opening of the engine based on the modified intake airflow.

A system for controlling combustion in a marine drive, the system comprising:

• an engine;
• a computer processor device;
• and
• a computer memory device comprising instructions that are executable by the computer processor device to control a timing of spark in the engine, by:
• determining 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;
• determining a humidity offset value based on a specific humidity of intake air to the engine and the load of the engine;
• determining a controlling spark advance value based on the base spark advance and the humidity offset value;
• and
• sending the controlling spark advance value to an ignition system of the engine.