An internal combustion engine includes an engine housing, a crankshaft supported within the engine housing for rotation with respect to the engine housing, and a flywheel fixedly mounted to the crankshaft and rotatable with the crankshaft in a starting direction to start the engine. A coil spring has an outer end fixedly interconnected with respect to the engine housing, and an inner end. A unidirectional clutch has a portion connected to the inner end of the spring. The unidirectional clutch is characterized by an interference condition in which the unidirectional clutch couples the inner end of the spring to the flywheel such that the flywheel and crankshaft may be rotated in the starting direction in response to unloading of the spring. The unidirectional clutch is also characterized by a non-interference condition in which the inner end of the spring is uncoupled from the flywheel. An input assembly is interconnected with the spring and selectively movable into contact with flywheel to load the spring in response to rotation of the flywheel. A locking mechanism selectively prevents the spring from unloading, and at least one manual actuator is actuable to disengage the locking mechanism from the spring to enable unloading of the spring.