pull the cord till it reaches all way to the end, take a screwdriver and lodge it between the plastic wheel and housing to keep it from recoiling, cut that knot in the end of the cord, pull the cord out, now holding the recoil tightly remove the screwdriver and try and get a few more turns tighter on the recoil, try and get the knot hole to line up with the cord hole as much as possible, lodge the screwdriver back in to hold it in place, insert your cord and tie a double knot in the end remove the screwdriver and now it should recoil all the way.It's original cord so maybe spring? How can I tighten it?
Try it my way. No undoing any knots. No disassembly.This happend with mine, all you have to do is undo the knot, pull the rope through the hole so the handle is butted up tight against the casing (Clamp the spring plastic bit), wind up the rope again and tie it off. Done.