Method for controlling a marine internal combustion engine

A method for controlling a marine internal combustion engine, the method being carried out by a control module and comprising:

• operating the engine according to an initial set of mapped parameter values that correspond to a combustion parameter, the initial set of mapped parameter values being configured to achieve a first target fuel-air equivalence ratio in a combustion chamber of the engine;
• determining a first actual fuel-air equivalence ratio in the combustion chamber;
• using a feedback controller to minimize a difference between the first target fuel-air equivalence ratio and the first actual fuel-air equivalence ratio;
• using outputs of the feedback controller to populate an initial set of adapt values by which to adjust combustion parameter values determined from the initial set of mapped parameter values;
• transitioning to operating the engine according to a subsequent set of mapped parameter values that correspond to the combustion parameter, the subsequent set of mapped parameter values being configured to achieve a second, different target fuel-air equivalence ratio in the combustion chamber;
• and
• after the step of transitioning, determining a second actual fuel-air equivalence ratio in the combustion chamber, using the feedback controller to minimize a difference between the second target fuel-air equivalence ratio and the second actual fuel-air equivalence ratio, and using the outputs of the feedback controller to populate a subsequent set of adapt values by which to adjust combustion parameter values determined from the subsequent set of mapped parameter values.