Dude, how are you gonna fix a BROKEN SPRING? I'll tell you, you are gonna go BUY ANOTHER PULLSTART.

I don't care if you pull 4 inches eventually that spring will fail and for one reson. There is a spot (by nature of design) in the spring that receives a disproportionate amount of stress, usually near where it tucks into the housing. This point begins to fatigue much more rapidly than the rest of the spring. It IS going to break, and it will do several times while your electric starters will not. I'm not talking about a starter box with motors that need to have their brushes and springs replaced either, but rather similar setups to what I mentioned above.