How To Fix The Pull String On A Lawn Mower

Diagnosing the Problem

Examine the pull string for any visible damage. Check for fraying, breakage, or knots. Note the condition of the handle and the recoil mechanism housing.

Attempt to pull the string slowly. Observe if there's any resistance or unusual noises. Listen for a clicking sound from the pawls engaging the engine's flywheel.

If the string pulls out completely without engaging the engine, or feels significantly looser than usual, the recoil spring is likely broken or disengaged.

Safety Precautions

Disconnect the spark plug wire before any work on the recoil starter. This prevents accidental engine starting.

Wear safety glasses to protect your eyes from debris and potential spring recoil.

If you're unfamiliar with engine repair, consider consulting a qualified mechanic.

Tools and Materials Needed

You will likely need the following:

• Screwdrivers (Phillips and flathead)
• Pliers (needle-nose and standard)
• Socket set or wrenches
• New pull string (if necessary)
• New recoil spring (if necessary)
• Lightweight grease
• Work gloves

Accessing the Recoil Starter

Locate the recoil starter housing, typically mounted on top of the engine. Remove any screws or bolts securing the housing cover. Some models may have clips or tabs holding the cover in place.

Carefully detach the cover, noting the orientation of any internal components. Be cautious as the recoil spring may be under tension.

If the recoil starter assembly is a separate unit, detach it from the engine housing by removing the mounting bolts.

Replacing the Pull String

Removing the Old String

Locate the knot or securing mechanism on the pulley inside the recoil housing. Use needle-nose pliers or a small screwdriver to release the string.

Carefully pull the old string out from the handle end, noting the path it takes through the housing and handle.

Installing the New String

Thread the new pull string through the hole in the handle and tie a secure knot. Ensure the knot is large enough to prevent it from slipping back through the hole.

Thread the other end of the string through the opening in the recoil housing and around the pulley.

Secure the string to the pulley using the appropriate knot or securing mechanism. A square knot is generally suitable.

Winding the Pulley

Hold the pulley in place and slowly wind the string around it, ensuring the string is evenly distributed.

Leave approximately 6-8 inches of string extended beyond the housing before releasing the pulley. This will allow for proper starting.

Test the string by pulling it slowly. It should retract smoothly and completely.

Replacing the Recoil Spring

Releasing Spring Tension

Warning: Recoil springs are under significant tension. Releasing the spring improperly can cause injury. If you are not comfortable with this step, consult a qualified mechanic.

If the spring is broken, it may already be loose. If it's still intact, you'll need to carefully release the tension.

Secure the recoil starter housing in a vise or with clamps. Use pliers to carefully detach the spring from its anchor point on the housing or pulley.

Slowly allow the spring to unwind. Do not release it abruptly, as it can snap back with considerable force.

Installing the New Spring

Apply a small amount of lightweight grease to the inside of the recoil housing where the spring will sit.

Carefully wind the new recoil spring into the housing, ensuring it's properly seated in its designated groove.

Secure one end of the spring to the anchor point on the housing. The other end will attach to the pulley.

Attaching the Spring to the Pulley

Align the pulley with the spring and carefully engage the spring's hook or loop with the corresponding feature on the pulley.

Ensure the spring is securely attached and properly seated before proceeding.

Pre-Winding the Spring

Before installing the pull string, pre-wind the spring to create tension. Rotate the pulley in the direction that tightens the spring. The number of turns will vary depending on the model, but typically 3-5 turns is sufficient.

Hold the pulley in the pre-wound position while installing the pull string.

Reassembling the Recoil Starter

Carefully align the recoil starter assembly with the engine housing and reattach it using the mounting bolts.

Ensure the recoil starter is securely fastened and that the pulley can rotate freely.

Reinstall the recoil starter housing cover, securing it with the screws, bolts, or clips.

Testing and Final Adjustments

Reconnect the spark plug wire.

Pull the starter string firmly and smoothly. The engine should crank over.

If the engine fails to start, double-check the fuel supply, spark plug, and other basic troubleshooting steps.

If the string does not retract properly, remove the housing cover and adjust the spring tension by adding or removing one turn of pre-wind. Reassemble and retest.

Troubleshooting Common Issues

• String breaks frequently: Use a higher-quality pull string. Ensure the string isn't rubbing against any sharp edges in the housing.
• String doesn't retract fully: Insufficient spring tension. Add another turn of pre-wind to the spring.
• String is hard to pull: Excessive spring tension. Remove one turn of pre-wind from the spring. Check for obstructions in the recoil housing.
• Engine cranks but doesn't start: This is likely an issue unrelated to the recoil starter. Investigate fuel, spark, and compression.

Key Takeaways

Repairing a lawn mower pull string involves understanding the recoil starter mechanism, prioritizing safety, and using the correct tools. A broken string typically requires replacement, while a disengaged or broken recoil spring necessitates careful handling due to its stored energy.

Proper diagnosis of the problem before disassembly is crucial. Pay close attention to the orientation of components and the path of the pull string during removal to facilitate reassembly. Pre-winding the recoil spring provides the necessary tension for string retraction.

If you are uncomfortable with any of these steps, consult a qualified mechanic. Attempting repairs without the necessary knowledge or skills can result in injury or further damage to the lawn mower.