Abstract: A starting system for compression ignition engines includes an auxiliary engine of the spark ignition type in combination with a conventional cranking motor of the compressed air or electric type. The components are arranged so that either the auxiliary engine or the cranking motor may be used for starting, or both may be used in tandem. The system is combined in a conveniently mounted equipment.The starting system comprises, in combination, a cranking motor having a main shaft, clutch means coupled to the main shaft for engaging the main shaft to the crank shaft of an engine to be started, an auxiliary engine of the spark ignition type, and transmission means including a one-way clutch interconnecting the auxiliary engine with said main shaft, whereby to permit said crank shaft to be driven selectively from said cranking motor or said auxiliary engine, or from said cranking motor and auxiliary engine driving in tandem.