Engine fuel delivery systems, apparatus and methods

A method of operating an engine, comprising:

• (a) determining a peak power condition for the engine by altering an air-fuel mixture ratio delivered to the engine and monitoring a change in an engine parameter that occurs as a result of the altered air-fuel mixture ratio until said monitored engine parameter indicates the peak power condition of the engine at that time;
• (b) measuring a temperature associated with the engine at said peak power condition;
• (c) comparing the temperature measured in step (b) with a previously determined temperature associated with a known peak power condition of the engine;
• (d) determining an offset value based on the comparison made in step (c);
• and
• (e) controlling at least one of an air-fuel mixture delivered to the engine or ignition spark timing relative to top dead center of a piston of the engine based on said offset value.