An electric power generation system (20) is disclosed, which includes an electric power generator (22) driven by a four-cycle internal combustion engine (30). The engine (30) includes a plurality of reciprocating cylinders (C1-C6) each rotatably coupled to a crankshaft (34), which drives the electric power generator (22). A controller (90) is included that is operable to control fueling to start the engine (30) as a function of engine temperature and determine initial engine start-up as a function of rotational engine speed. This controller (90) regulates engine acceleration until a target engine speed is reached from initial start-up. Once this target speed is reached, the controller (90) provides a speed governor function.