How do you fix a lawn boy pull cord?

What is a lawn boy pull cord?

A lawn boy pull cord is the starter rope found on push lawn mowers and self-propelled lawn mowers. It is a nylon rope that connects to the starter assembly and recoil spring inside the mower engine. Pulling the starter cord turns the engine flywheel, which spins the crankshaft to start the engine. If the pull cord is broken or not retracting properly, the mower will not start.

Common problems with lawn boy pull cords

There are a few common problems that can occur with lawn boy pull start cords:

Broken or frayed rope

Over time, the rope can become dried out and brittle from heat and sunlight exposure. This causes it to break or fray. Fraying makes it harder to grip and completely broken ropes prevent the engine from starting.

Recoil spring failure

Inside the starter housing is a recoil spring that retracts the rope after it’s pulled. This spring can become stretched out or corroded over time. A failed recoil spring will prevent the rope from retracting properly.

Starter pulley jam

The rope wraps around a pulley connected to the flywheel when pulled. Debris, rust, or worn components can cause this pulley to jam, making the rope hard to pull.

Damaged starter housing

The plastic starter housing can become cracked or damaged over time. This allows dirt and debris to enter the starter, leading to jammed pulleys, frayed ropes, and recoil spring failure.

How to replace a lawn boy pull cord

If your lawn mower won’t start due to pull cord issues, replacing it is usually the fix. Here are the steps to replace a lawn boy pull start cord:

Step 1: Disconnect the spark plug wire

Before working on the mower, always disconnect the spark plug wire. This prevents accidental starting while working.

Step 2: Remove the recoil starter

There are usually between 2-4 screws or bolts holding the starter housing onto the mower. Remove these to detach the starter.

Step 3: Cut off the old rope

Cut the old rope off as close to the pulley as possible. If you can’t detach the pulley from the old rope, the whole pulley will need replacement.

Step 4: Thread the new rope

Tie a tight double knot at one end of the new starter rope. Thread the new rope through the starter pulley and housing according to the routing diagram for your mower model.

Step 5: Reattach pulley and spring

If disassembled, reattach the starter pulley and recoil spring. Refer to your mower manual for proper reassembly. The spring must be anchored in place for the auto-rewind to work.

Step 6: Tie the rope to the handle

Pull the rope through the starter housing, leaving about 4 inches extending from the starter handle. Tie a knot to secure the starter handle.

Step 7: Test and reinstall

Test the recoil action before reinstalling the starter. Make sure the rope retracts fully. Reinstall the starter onto the mower and reconnect the spark plug wire. Give the new rope a strong pull to start the mower.

How to fix a stuck or jammed lawn boy pull cord

If the starter rope pulls out but does not retract on its own, the spring or pulley is likely jammed. Try these steps:

Step 1: Remove starter housing

Disconnect the spark plug wire and detach the starter assembly from the mower as described in the replacement steps.

Step 2: Clean the pulley and housing

Clean out any debris inside the starter housing that could cause sticking. Remove grass clippings and built up dirt. Spin the pulley by hand to test for sticking.

Step 3: Lubricate the spring and pulley

Apply a light oil or lubricant, like WD-40, inside the starter housing and to the rope pulley. This prevents binding from rust and corrosion.

Step 4: Check the starter spring

Examine the recoil spring inside the starter housing. If broken or loose, it will need replacement. An anchor to hold the spring in place may also be loose or broken, requiring repair.

Step 5: Reassemble

Reassemble the starter components. Make sure the spring and all retention clips are properly anchored. Test the rope retraction before reinstalling on mower.

Step 6: Replace starter housing if needed

If cleaning and lubrication don’t fix the issue, the entire starter housing assembly may need replacement due to internal wear or damage.

Following these steps should get a jammed or stuck pull cord recoiling properly again. If not, the starter needs replacement.

How to replace a lawn boy pull cord starter assembly

If cleaning and lubricating the pull start components don’t remedy problems with the recoil starter, replacing the entire starter assembly will be required:

Step 1: Remove old starter

Detach the defective starter assembly from the mower, unscrewing mounting hardware. Cut away the old starter rope.

Step 2: Install new starter

Attach the new starter assembly using original mounting screws. Make sure the starter is aligned properly before tightening fasteners.

Step 3: Thread new rope

Follow the starter routing diagram to thread the new rope through the pulleys and housing. Leave about 4 inches extending from handle.

Step 4: Tie knot and test

Tie a knot at end of the rope and make sure the handle is secured. Test the recoil action before reconnecting spark plug wire.

Step 5: Reconnect spark plug wire

After confirming proper starter operation, reconnect the spark plug wire to the spark plug. The mower should now start when the new pull cord is pulled.

Purchasing a replacement starter assembly specific to your mower make and model will come with a new pulley, spring, and housing. This ensures smooth, reliable starting. Follow any specific instructions included with the new starter.

How to replace a lawn boy pull cord handle

If only the plastic starter handle is broken on the existing pull cord, just this part can be replaced:

Step 1: Remove starter housing

Detach the starter assembly from the mower to access the pull rope.

Step 2: Untie broken handle

Untie the knot securing the broken pull cord handle. Discard the damaged handle.

Step 3: Tie on new handle

Slide the replacement handle onto the pull rope. Position about 4 inches from the starter housing. Tie a secure knot to hold the new handle.

Step 4: Test handle

Hold the rope taut and test the new handle before reinstalling the starter. Confirm it is tied securely.

Step 5: Reinstall starter

With the new handle installed, reattach the starter assembly onto the mower. Reconnect the spark plug wire when finished.

This allows fixing a broken starter handle without replacing the entire rope or starter. Match the new handle to the original size and style.

How to adjust the recoil spring on a lawn boy starter

If the recoil starter rope doesn’t retract fully and quickly, the spring may need adjustment:

Step 1: Remove starter

Disconnect spark plug wire and detach starter assembly from mower.

Step 2: Access spring

Carefully disassemble components to access recoil spring. Refer to manufacturer instructions.

Step 3: Remove rope from pulley

Unwind all rope from pulley and disconnect spring from anchor point. Caution – spring is under tension.

Step 4: Adjust spring length

To increase spring tension, carefully stretch the spring out slightly. Compress spring to reduce tension.

Step 5: Reinstall spring

Reconnect spring to anchor point under adjusted tension. Secure with any clips.

Step 6: Reassemble starter

Making sure spring is properly seated, reinstall pulley, rope, housing, and handle.

Step 7: Test recoil

Check that the adjusted spring provides strong recoil action before reconnecting spark plug and reinstalling on mower.

Adjusting spring length is an effective way to optimize starter rope retraction. Take safety precautions when working with spring tension. Refer to manufacturer guidelines for proper tension settings. Too much tension can over-wind the rope.

How to replace a lawn boy pull cord recoil spring

If the recoil spring is broken or has lost its tension, the spring will need complete replacement:

Step 1: Remove starter assembly

Detach the pull starter unit from the mower by removing mounting screws.

Step 2: Remove rope and pulley

Unwind all starter rope from the pulley and disconnect it. Remove pulley.

Step 3: Unhook spring

Detach the spring from its anchor point inside the starter housing. Caution – spring will be under tension.

Step 4: Install new spring

Hook one end of the replacement spring into the housing anchor point.

Step 5: Adjust tension

Stretch or compress spring to set proper tension. Refer to manufacturer specs.

Step 6: Reinstall pulley and rope

With spring anchored in housing, reattach pulley and thread new starter rope.

Step 7: Reassemble starter

Install handle and test recoil action before reinstalling starter onto mower.

Step 8: Connect spark plug wire

After starter is reinstalled, reconnect the spark plug wire to test engine starting.

Always exercise caution when working with recoil springs. Wear safety glasses and gloves in case of slips. Use replacement springs that meet the specifications for your mower model. Proper spring tension is important for easy starting.

Conclusion

Troubleshooting and repairing lawn mower pull cord issues involves inspecting the rope, pulleys, spring, and starter housing. Replace broken or frayed ropes. Clean and lubricate jammed pulleys and housings. Adjust or replace weakened recoil springs. If components are too worn, replace the entire starter assembly. With proper maintenance and replacement of worn parts, lawn mower pull starters should provide years of starting reliability. Follow all safety procedures when working on the recoil spring and around mower engines.