Then replace the gear and spring assembly (bendix gear) that engages the ring gear on the fly wheel. The other possibility is the ring gear is worn so badly the teeth won't engage. You can try and crank the engine about 90 degree by hand and try again. Most likely the starter gear that engages the fly wheel ring gear is bad. Mine was doing the same thing. Replaced the bendix gear assembly and it works fine. You just have to remove the starter and take off the wishbone assembly from the stomp starter.
