Abstract: A starting device for an engine wherein a drive shaft associated with a starting motor is connected through a one-way clutch to a pinion gear for driving a ring gear of the engine. The device comprises a first sleeve slidably fitted on the drive shaft, a second sleeve slidably fitted on the first sleeve, a drive clutch member for the one-way clutch slidably fitted on the second sleeve, and a buffer spring between the first sleeve and the one-way clutch. The first helical spline between the drive shaft and the first sleeve imparts a great forward thrust to the pinion gear by utilization of the turning force of the drive shaft into complete engagement with the ring gear so as to positively drive the latter. An excessive load may be absorbed by compressive deformation of the buffer spring.