If your lawn mower won’t start because the cord snapped, learning how to replace a lawn mower pull string is a straightforward repair. Replacing a broken lawn mower pull string will get your machine running again with just a few common tools. You can save time and money by fixing it yourself in under an hour.
This guide walks you through the entire process step-by-step. We’ll cover the tools you need, how to access the recoil starter, and the correct way to wind the new spring. By the end, you’ll have the confidence to tackle this common repair.
How To Replace A Lawn Mower Pull String
The core process involves removing the starter assembly, installing a new cord, and carefully rewinding the recoil spring. While designs vary slightly between mower brands, the fundamental steps are the same. Always prioritize safety by disconnecting the spark plug before beginning any work.
Tools And Materials You Will Need
Gathering the right items before you start makes the job smoother. You likely have most of these tools already in your garage. Here is your checklist:
- A replacement pull cord (check your mower’s manual for length and thickness)
- A standard set of screwdrivers (flat-head and Phillips)
- A pair of needle-nose pliers
- A socket set or wrench for removing the starter assembly bolt
- A sturdy work glove to protect your hand from the spring
- A small container to hold screws and small parts
Safety Precautions Before You Begin
Your safety is the most important part of this repair. A lawn mower’s recoil spring is under high tension and can cause injury if released unexpectedly. Follow these precautions carefully.
- Disconnect the spark plug wire. This prevents the engine from accidentally starting while you are working on it.
- Allow the engine to cool completely if the mower was recently used.
- Work on a clean, flat, and well-lit surface like a workbench or sturdy table.
- Wear safety glasses to protect your eyes from dirt and debris.
- Keep your fingers clear of the recoil spring mechanism at all times.
Locating The Recoil Starter Assembly
The recoil starter is typically housed under a plastic cover on the top of the mower engine. On many models, this cover is held in place by three or four screws. Some mowers have the starter built directly into the engine housing, requiring you to remove the entire blower housing.
Step-By-Step Replacement Instructions
Now, let’s get into the detailed steps for replacing the cord. Take your time and refer to these instructions as you go. If you get stuck, it’s okay to pause and reassess.
Step 1: Remove The Starter Housing
First, locate and remove the screws securing the starter cover or housing to the engine. Place the screws in your container so they don’t get lost. Gently lift the housing straight up and away from the engine. You may need to wiggle it slightly if it’s snug.
Be careful not to yank it, as the recoil spring inside is still connected. Once the housing is free, set it on your work surface with the interior facing up. You should see the pulley, the broken cord, and the coiled spring.
Step 2: Release The Old Cord And Spring Tension
This step requires caution. The spring is wound tightly. Use your needle-nose pliers to grip the knot or metal clip securing the broken cord to the pulley. Untie or unclip the old cord from the pulley’s center hole.
Slowly allow the pulley to rotate in the direction it wants to go, letting the spring’s tension unwind completely. The pulley should spin freely with no resistance when the spring is fully relaxed. Do not let the pulley spin wildly; control it with your hand.
Step 3: Install The New Pull Cord
Take your new cord and tie a secure knot at one end. A figure-eight or double overhand knot works well. Feed the unknotted end of the cord through the hole in the starter handle, if it’s not pre-attached, and tie another secure knot.
Now, feed the other end of the cord (the one with the knot) through the exit hole on the starter housing and then down into the center hole on the pulley. Pull it through until the knot seats firmly against the pulley. You may need to use a piece of wire as a guide to thread it through the housing hole.
Step 4: Wind The Recoil Spring And Pulley
This is the trickiest part. Wearing a glove, turn the pulley in the direction opposite of its natural unwind direction. This is usually clockwise. Wind the pulley until the spring is tight, then turn it back (counter-clockwise) about two full turns.
This creates the necessary pre-tension for the cord to retract. While holding the pulley in place, carefully pull the cord out of the housing and wrap it around the pulley groove a few times. This prevents it from snapping back while you reassemble.
Step 5: Reassemble And Test The Starter
Align the starter housing back over the engine, ensuring the cord is not pinched. Gently press the housing down and reinstall all the screws, tightening them snugly but not overly tight. Before reconnecting the spark plug, give the pull cord a slow, smooth test pull.
The cord should extend and retract smoothly. If it doesn’t retract, the spring may not have enough tension. If it’s too hard to pull, something may be binding. Once the action is smooth, reconnect the spark plug wire. Your mower is now ready for a test start.
Common Problems And Troubleshooting Tips
Sometimes, things don’t go perfectly on the first try. Here are solutions to common issues you might encounter during the repair process.
The Cord Does Not Retract
If the cord hangs loose and doesn’t reel back in, the recoil spring likely isn’t engaged or is broken. You may not have wound it enough during Step 4. You’ll need to reopen the housing and rewind the spring, ensuring you create that crucial pre-tension. In rare cases, the spring itself can be broken and will need replacement.
The Cord Is Too Hard To Pull
A stiff or jerky pull often indicates the spring was wound too tightly or the cord is binding against the housing. Check that the cord is routed cleanly through the exit hole and that the housing is seated correctly on the engine. Also, ensure you didn’t overwind the spring past its recommended tension.
The New Cord Snaps Immediately
A brand-new cord breaking suggests a problem with the pulley or housing. Inspect the pulley groove and the cord exit hole for any sharp edges or burrs that could be cutting the cord. Lightly sanding any rough spots with fine sandpaper can prevent future breaks.
When To Call A Professional
While this is a DIY-friendly job, some situations warrant professional help. If the recoil spring is broken or has jumped out of its housing, it can be very dangerous to handle without experience. If the starter housing or pulley is cracked or damaged, you may need to replace the entire assembly, which a small engine mechanic can do quickly.
If you’ve followed all steps and the mower still won’t start, the problem could be unrelated to the pull cord, such as a fuel issue or a faulty spark plug. A technician can provide a full diagnosis.
Maintenance Tips To Prevent Future Breaks
Taking care of your pull cord system can extend its life significantly. A little preventative maintenance saves you from repeating this repair next season.
- Always pull the cord straight out in a smooth, steady motion. Yanking it at an angle causes extra wear.
- Keep the cord and housing clean from grass clippings and debris, which can cause friction.
- Periodically apply a small amount of silicone spray lubricant to the pulley mechanism to keep it moving freely.
- Store your mower in a dry place to prevent rust and corrosion on the spring and pulley.
Frequently Asked Questions
Here are answers to some common questions about replacing a lawn mower pull cord.
What Kind Of Cord Do I Need For My Lawn Mower?
You need a specific lawn mower replacement pull cord, available at hardware stores or online. Check your owner’s manual for the correct diameter (often 3/32″ or 1/8″) and length. If you don’t have the manual, measure the old cord or take it with you to the store for matching.
Can I Use Any Rope As A Replacement?
It is not recommended. Regular rope isn’t designed to withstand the friction, tension, and weather conditions a mower cord endures. It can fray, stretch, or break quickly. Always use a purpose-made nylon lawn mower pull cord for a safe and lasting repair.
How Do I Know If The Recoil Spring Is Broken?
If the pulley offers no resistance when turned, or if you hear a rattling sound inside the housing, the spring is likely broken or disconnected. A broken spring will not retract the cord at all, leaving it completely limp.
Is It Difficult To Replace A Pull Start Cord?
For most people, it is a moderately easy repair. The hardest part is managing the recoil spring tension. By following clear instructions and working carefully, most homeowners can complete the job successfully in less than an hour.
How Much Does A Professional Charge For This Repair?
A shop typically charges between $75 and $150 for labor and parts, depending on your location and the mower model. Doing it yourself costs only the price of the cord, usually between $5 and $15, making it a significant savings.