Pull-cord problems are common with lawn mowers. You may be tempted, when you are trying to correct the problem, to try to overpower the problem with force--but that is a sure way to damage the mower or injure your arm. There are a few techniques you can try to solve the issue. If the pull-cord problem still keeps the mower from starting, you may need to replace the recoil spring.
Things You'll Need
Apply some spray lubricant to the cord and slowly pull the cord in and out, working the spray lubricant into the compartment. Repeat the procedure a few times.
Extend the rope (if the rope won't completely retract). Loosen the motor-blowing bolts, have the rope extended, and strike the housing with the palm of your hand, The rope should retract if misalignment was the problem. Tighten the motor-blowing screws. If the rope does not retract, the recoil spring should be replaced. This is a touchy area. You likely should bring it to your repair shop if you haven't fixed a recoil spring before. A lot of damage can be caused if you make a mistake when trying to repair it yourself, costing you hundreds of dollars.
Replace the spring coil if the rope goes limp.
Check under your mower for a bent blade.
Reference the owner's manual for additional troubleshooting methods.
Always keep the area clear of bystanders and children when working on and running equipment.
Always wear eye protection, gloves and appropriate clothing.
Always turn the mower off and remove the spark plug when working on or near the area of the blades or any part of the mower.