The disassembly of many small engines often requires the initial removal of the recoil starter assembly, commonly known as the "pull starter." The main component of this assembly is a flat spring which is usually contained in a small metal housing. Because of its design, it is easy to inadvertently dislodge this flat spring and cause it to come flying out. Without knowledge of the proper technique, re-coiling this spring is a difficult and frustrating task. The implementation of a few well-planned steps will shed light on the secrets of replacing a recoil starter spring.
Verify that the rewind spring is not broken and that is has just become unattached. The spring should have a small bend near its beginning and at the end to hold it firmly in its housing. If it does not, the spring has broken and will need to be replaced. In either case, it must also be rewound.
Ready the housing by making it free of all dirt and oily grime which could cause the spring to not fit or wear prematurely. Grasp the spring between the thumb and index finger so that the index finger is in the centre of the coil and the thumb serves to pinch the coil together at one point.
Pull firmly on the loose end of the spring. This will cause the coil to tighten in diameter while lengthening the loose end. While still keeping the coil pinched (using your thumb and index finger) to prevent unwinding, roll the coil to shorten the loose end. Keep pinching and rolling (winding) the spring until the diameter of the coil is small enough to fit back into the coil housing.
Replace the coil into the housing by aligning the tab on the end of the coil with the small slot in the housing. Slowly release pressure on the spring to relax the coil into position in the housing. Use the starting string and the notch provided on the string spool to wind the spring in the direction the spool usually unwinds. This will put tension on the spring so that when the starter string is released, it will wind itself back into the housing.
Replace the coil housing and spring assembly onto the flywheel cover (it goes inside) of the engine per the instruction manual (if available), making sure all bolt or screw holes are aligned properly. Replace the recoil starting string assembly onto the engine, and fasten it securely using hex head bolts or screws. At this point, the recoil starting system is fully functional. Test it for normal operation (pull it several times--it should spin the engine, then rewind itself).
Lubricate the spring. This will prevent water from entering the space between the coils and prevent corrosion. This will also prevent wear on the coil as the winds slide past one another.