I take it your taking about the pull cord recoil. If so, I would first check the housing screws. if they have loosen if can cause the paws not to catch. IF that's not it you will have to take the throttle handle and shaft off. remove the screws holding the two halfs of the plastic engine cover. you will see the recoil down in the bowl of the front cover. There is usually two spring loaded levers on the flywheel that may be stuck. If so wash them off with carb cleaner and lub them with Wd40 or something similar. Ensure they spring back.

I would also look at the rope while you have it apart. If it's bad all you got to do is pull the rope all the way out aligning the entry and exit holes so the rope will pull straight out of the housing andn off the spool. stick a small screwdriver, scribe or drill bit to lock the spool with the little half moon slot provided. Now look how the rope is wrapped (take a picture it you have to) remove the screw that locks the rope and pull the rope out spool.

Do the reverse thread the rope through the housing into the spool and wrap it around the as noted during removal and reinstall the screw. install the shaft, Assemble the throttle handle plastic halfs, reassemble the throttle handle watching not to pinch the cable between the trottle handle halfs or bumping the trigger off the stud provided that it swivels on. Other than removing the coil spring (which it a real pain in the @) thats about it unless I forgot something??????...