Anyone ever try to "fix" that rope before?
Sounds like it might have been broken at one time and the spring never got fully wound.
Most starters are pretty easy to fix but the failing most folks have is not putting enough tension on the spring to draw the rope back in. Easy fix if you know how but it's a bit counter-intuitive because you feel like you are over-winding the assembly.
Is there a mower shop anyplace near to him?