If your lawn mower’s starter rope has snapped or frayed, learning how to change the pull string on a lawn mower is a straightforward repair you can do yourself. Replacing the pull string on a lawn mower restores the simple mechanical action needed to start the engine. This guide will walk you through the entire process with clear, step-by-step instructions.
You do not need to be a mechanic to complete this fix. With a few common tools and a replacement cord, you can have your mower starting smoothly again in under an hour. This repair saves you money on a service call and gets your yard work back on track quickly.
How To Change The Pull String On A Lawn Mower
This section provides the complete, start-to-finish procedure. Before you begin, ensure the mower is on a flat, stable surface and the spark plug wire is disconnected to prevent any accidental starts. Safety is the most important first step.
Tools And Materials You Will Need
Gathering the right items before you start makes the job go smoothly. You likely have most of these tools already in your garage.
- Replacement pull cord (check your mower’s manual for the correct length and diameter)
- Socket set or screwdrivers (flathead and Phillips)
- Needle-nose pliers
- A pair of vise grips or locking pliers
- Scissors or a sharp knife
- A lighter or small torch (for melting rope ends)
- A clean cloth
Step 1: Access The Recoil Starter Assembly
First, you must remove the starter housing to reach the recoil mechanism. This is usually held in place by three or four screws on the top of the mower engine. Use the appropriate screwdriver or socket to remove them.
Carefully lift the housing off. You may need to gently pry it if it’s stuck, but avoid using excessive force. Underneath, you will see the recoil starter assembly, which contains the spring and pulley.
Step 2: Remove The Old Pull Cord
Now, you need to carefully disassemble the recoil unit. Place the assembly on your work surface with the pulley facing up. The knot holding the old cord is typically tucked into a notch in the pulley.
- Slowly pull out a few inches of the remaining old cord until you see the knot.
- Use needle-nose pliers to untie or release the knot from the pulley’s anchor hole.
- Gently pull the cord out of the housing’s handle and discard it.
Important: Do not let the pulley spin freely as you release the cord. The recoil spring inside is under tension. If it unwinds suddenly, it can be dangerous and difficult to rewind.
Step 3: Wind The Recoil Spring (If Needed)
If the spring did unwind, you will need to rewind it before installing the new cord. This is a critical step that requires patience.
- Hold the assembly firmly. Use a screwdriver to carefully lift the spring coil from its central anchor point.
- Rotate the pulley in the direction opposite of the pull (usually clockwise) until you feel resistance. You may hear a soft clicking as the spring tightens.
- Make about 3 to 4 full rotations. The spring should now be under light tension, ready for the new cord.
Be cautious during this process. A slipped spring can cause injury, so take your time.
Step 4: Install The New Pull Cord
With the spring under proper tension, you can thread the new rope. Start by preparing the cord’s ends.
- Cut your replacement cord to the correct length, matching the old one.
- Use a lighter to melt the cut ends slightly. This prevents fraying and makes threading easier.
- Thread one end of the new cord through the exit hole in the starter housing.
- Pull it through and tie a secure knot at the end that will sit inside the handle. A figure-eight or double overhand knot works well.
- Feed the other end of the cord through the anchor hole in the pulley.
- Tie another secure knot here, but do not pull it tight just yet.
Step 5: Wind The Cord Onto The Pulley
This step requires you to slowly release the spring’s tension while the cord winds around the pulley.
- With the knot in the pulley’s hole, gently turn the pulley against the spring’s tension (the direction you pulled to start the mower).
- Wind the cord neatly onto the pulley. Keep turning until only about 6 to 8 inches of cord remains outside the housing.
- Now, pull the knot tight into its anchor notch on the pulley. You may need pliers to tug it securely into place.
Step 6: Reassemble And Test
You are almost done. Now you need to put everything back together.
- Carefully place the recoil starter assembly back into the housing, ensuring the cord exits cleanly.
- Align the screw holes and reinstall the starter housing onto the mower engine. Tighten all screws firmly.
- Reconnect the spark plug wire.
- Give the new pull cord a slow, steady test pull. It should extend smoothly and retract back into the housing. If it doesn’t retract, the spring may need more tension.
Your mower should now be ready for use. If the engine still doesn’t start, the issue may be with fuel or the spark plug, not the starter cord.
Common Mistakes To Avoid
Being aware of these pitfalls can save you time and frustration.
- Not disconnecting the spark plug. Always do this first for safety.
- Letting the recoil spring unwind uncontrollably. Control the pulley at all times.
- Using a cord that is too thick or too thin. This can cause jamming or rapid wear.
- Over-winding the spring. This puts excessive stress on it and can lead to premature failure.
- Forgetting to melt the ends of the new cord. Frayed ends can jam in the mechanism.
Choosing The Right Replacement Pull Cord
Not all pull cords are the same. Using the correct one is essential for a lasting repair. The wrong size can lead to immediate problems.
Determining Cord Length And Diameter
The best way to find the right cord is to measure your old one. If it’s completely gone, check your mower’s owner manual for specifications. As a general rule, most walk-behind mowers use a cord between 36 and 48 inches long.
Diameter is equally important. Common sizes are 3/32 inch or 1/8 inch. A cord that is too thick will not spool correctly inside the housing and may bind. A cord that is too thin may not be strong enough and could break quickly.
Material And Handle Considerations
Pull cords are typically made from durable, weather-resistant nylon. You can buy universal replacement kits that include a cord and a new handle, or you can purchase bulk cord by the foot.
If your old handle is cracked or broken, a kit is a good choice. The handle is usually attached with a simple knot or a metal clamp that you can squeeze with pliers. Make sure the new handle is comfortable and provides a good grip.
Troubleshooting Recoil Starter Problems
Sometimes, a broken cord is a symptom of a larger issue with the starter assembly. Here are some common problems and their solutions.
The Cord Does Not Retract
If the new cord pulls out but does not wind back in, the recoil spring is likely not engaged or is broken.
- Check that the spring’s inner hook is properly anchored in the center post of the assembly.
- The spring may have become dislodged. You may need to rewind it following the steps above.
- In rare cases, the spring can break. This requires replacing the entire recoil spring assembly, which is still a manageable repair.
The Cord Is Hard To Pull
A stiff or jerky pull can indicate other issues beyond the cord itself.
- The cord may be routing incorrectly inside the housing, causing friction. Check the path is clear.
- Dirt and grass clippings can jam the pulley. Clean the entire assembly with a cloth before reinstalling.
- The problem might be with the engine, not the starter. Ensure the mower blade can turn freely and the engine isn’t seized.
Frequent Cord Breakage
If cords keep snapping on you, look for these underlying causes.
- A sharp edge inside the starter housing exit hole can fray the cord. Smooth it with a small file or sandpaper.
- The recoil spring may be too tight, putting extra strain on the cord. Slightly relieving the spring tension can help.
- You might be pulling the cord at an extreme angle. Always pull straight out for a smooth, even motion.
FAQ Section
How Often Should I Replace My Lawn Mower Pull Cord?
There is no set schedule. Replace the cord when you see signs of fraying, when it becomes difficult to pull, or if it snaps. With proper use, a good quality cord can last for many seasons.
Can I Use Any Type Of Rope To Fix A Lawn Mower Starter?
No. You should always use a nylon replacement pull cord designed for small engines. Other ropes lack the necessary flexibility, strength, and heat resistance. Using the wrong material is a common reason for immediate failure.
What Do I Do If The Recoil Spring Flys Out?
If the spring comes completely out, reassembly is more complex but possible. Wear safety glasses and gloves. Carefully re-coil the spring into its housing, hooking the inner end to the center post first. It requires patience, but many online videos can visually guide you through this specific task.
Is It Cheaper To Replace The Pull Cord Or The Whole Starter Assembly?
Replacing just the cord is almost always cheaper. A cord costs only a few dollars, while a complete recoil starter assembly can cost significantly more. The cord replacement is also less wasteful, as you are fixing the specific broken part.
Why Does My Pull Cord Keep Getting Stuck?
A sticking cord is often caused by a misaligned or damaged pulley, a worn recoil spring, or debris in the mechanism. After checking for dirt, inspect the pulley for cracks and ensure it spins freely. Sometimes, the issue is that the cord was wound incorrectly during installation.