After you get the spring installed, you still have to preload it so that it's under tension when the cord is retracted. You just have to have the pull handle off the rope, wind the spring a couple of times, stick the rope back through the hole on the starter cover, fish the rope through the hole on the starter handle, and tie a knot. It should now snap back, just don't over do it so that the spring binds or comes off the tab when you pull the starter rope all the way out.