Direct Answer: How to Replace a Lawn Mower Pull String

To replace a lawn mower pull string, disconnect the spark plug wire for safety, locate the recoil starter housing on your mower’s engine, remove the old cord by unspooling it from the pulley, thread new 3–4mm diameter cord through the housing and around the pulley, secure it with a knot, wind it back onto the pulley, reattach the handle grip, and test the recoil action. The entire process typically takes 15–30 minutes depending on your mower model and your familiarity with small engine repair.

Understanding Your Lawn Mower’s Pull String System

Internal diagram of lawn mower recoil starter components and cord routing

What Is a Pull String and Why Does It Fail?

A lawn mower pull string (also called a pull cord or recoil starter cord) is a nylon or polyester rope attached to your mower’s engine recoil starter mechanism. When you pull the handle, the cord unwinds from a spring-loaded pulley, which spins the engine’s crankshaft to start the motor. The cord then automatically retracts.

Pull strings fail for several reasons:

  • Fraying and breakage: Repeated pulling and friction cause the cord to fray, thin, and eventually snap.
  • UV degradation: Outdoor storage exposes the cord to sun damage, making it brittle.
  • Moisture and mold: Damp storage conditions rot the cord fibers.
  • Knot failure: The knot securing the cord to the handle or pulley can loosen or slip over time.
  • Tangling: The cord may wrap around itself inside the housing, preventing proper retraction.

A failed pull string is one of the most common lawn mower problems, but it’s entirely DIY-fixable without special tools or expertise.

Where Is the Recoil Starter Located?

The recoil starter housing is mounted directly on the engine block and is typically the most visible assembly on top of or to the side of the engine. Location varies slightly by mower type:

  • Push mowers: The recoil starter is usually mounted horizontally on the upper engine block, with the pull handle accessible from above or to the side.
  • Self-propelled mowers: Similar to push mowers, but the housing may be positioned slightly differently depending on deck design.
  • Riding mowers: Often located on the side of the engine or near the operator’s seat for easy reach.

If you can’t locate it immediately, look for the pull handle grip—it’s always connected to the recoil starter housing by the cord.

Safety Precautions Before You Start

  • Disconnect the spark plug wire: Remove the rubber boot from the spark plug to prevent accidental engine ignition.
  • Allow the engine to cool: Wait at least 30 minutes after last use so you don’t burn yourself on hot metal.
  • Be cautious of spring tension: The recoil starter spring is under tension. Work slowly and deliberately to avoid sudden unwinding.
  • Work on a flat, stable surface: Place your mower on level ground to prevent it from rolling or tipping.
  • Wear work gloves: Protect your hands from sharp edges on the housing and pulley.

Tools and Materials You’ll Need

Essential Tools

  • Socket set or adjustable wrench (typically 8mm–12mm sockets for most mowers)
  • Screwdriver (Phillips and flathead)
  • Pliers or vise grips
  • Work gloves
  • Small brush (to clean the recoil housing)

Replacement Cord Specifications

Lawn mower pull cords are standardized in diameter and material. Most mowers use one of these sizes:

  • 3mm diameter: Common on smaller push mowers and older models.
  • 3.5mm diameter: Mid-range standard for most residential push mowers.
  • 4mm diameter: Typical for larger self-propelled and some riding mowers.

The cord is made of braided nylon or polyester, which is durable and weather-resistant. Do not substitute with natural rope, twine, or fabric cord—they won’t withstand the tension and friction.

Pre-cut replacement cord kits are available at hardware stores, home improvement retailers, and online marketplaces. A typical kit includes 15–20 feet of cord, which is more than enough for any residential mower. Cost ranges from $5–$15 per kit.

Where to Buy Replacement Cord

  • Home Depot, Lowe’s, Ace Hardware: Lawn mower maintenance sections stock pre-cut cord kits.
  • Amazon and eBay: Search for “lawn mower pull cord” with your mower’s brand and model for exact-fit replacements.
  • Local lawn mower repair shops: They often sell bulk cord and can advise on your specific model.
  • Manufacturer parts dealers: Briggs & Stratton, Honda, Toro, and other engine makers sell OEM cord through their distributor networks.

Step-by-Step Cord Replacement Process

Step 1: Access the Recoil Starter Housing

Depending on your mower model, you may need to remove the top plastic cover or air filter housing to access the recoil starter bolts. For most push mowers:

  1. Locate the bolts securing the recoil starter housing to the engine block. These are typically 8–10mm bolts.
  2. Using a socket wrench, remove all bolts. Keep them in a small container so you don’t lose them.
  3. Gently pull the recoil starter housing away from the engine. Be careful—the spring inside is under tension.
  4. Set the housing on a clean work surface, bolt-side down.

Tip: Take a photo of the housing in place before removal. This helps you remember the correct orientation for reassembly.

Step 2: Remove the Old Cord

Once the housing is removed, you’ll see the pulley (the spool where the cord wraps) in the center:

  1. Locate where the old cord is tied to the handle grip. This is typically a simple overhand knot or a loop knot.
  2. Cut or untie this knot and remove the handle grip from the old cord.
  3. Unspool the cord from the pulley by turning the pulley slowly by hand. The cord will unwind in overlapping layers. Work patiently to avoid tangling.
  4. Once fully unspooled, locate where the cord is tied to the pulley itself (usually on an anchor point or hole). Cut this knot and remove the old cord completely.
  5. Discard the old cord.

Warning: Do not force the pulley to spin rapidly. The internal spring can unwind suddenly and cause injury.

Step 3: Prepare the New Cord

Before threading the new cord, prepare it to prevent fraying:

  1. Cut a length of new cord approximately 6–8 inches longer than the old cord was (you’ll trim excess later).
  2. Lightly melt the cut ends of the nylon cord using a lighter or match, moving the flame quickly past the end to seal the fibers. Do not hold the flame directly on the cord—this will burn it.
  3. Let the sealed ends cool for 10 seconds before handling.

Step 4: Thread and Secure the New Cord to the Pulley

This step requires care to ensure the cord is anchored correctly:

  1. Locate the anchor hole or notch on the pulley where the old cord was tied.
  2. Insert one end of the new cord through this hole or around the anchor point.
  3. Tie a secure knot (a double overhand knot or a figure-eight knot works best) to prevent the cord from slipping. Pull hard on the cord to test the knot.
  4. Trim excess cord from this end, leaving about ½ inch beyond the knot.
  5. Seal this cut end with a lighter as before.

Step 5: Wind the Cord Onto the Pulley

Proper winding is critical for smooth operation:

  1. Hold the loose end of the cord in one hand and slowly rotate the pulley clockwise (or counterclockwise, depending on your mower—check which direction the old cord wound).
  2. Guide the cord onto the pulley so it wraps in neat, overlapping layers without crossing over itself or bunching.
  3. Continue winding until the cord is fully spooled and only about 5–6 feet of cord extends from the pulley (this becomes the pull handle section).
  4. The cord should wind tightly but not so tight that it restricts the pulley from moving freely.

Pro tip: If the cord springs back or resists winding smoothly, you may have wound it in the wrong direction. Unwind and start again in the opposite direction.

Step 6: Attach the Handle Grip

The free end of the cord now becomes the pull handle:

  1. Insert the cord end through the handle grip (a plastic or foam sleeve with a hole at each end).
  2. Tie a large overhand knot or loop knot at the end of the cord to prevent it from pulling back through the grip during use.
  3. Pull hard on the handle to test the knot.
  4. If your original handle grip is still intact, reuse it. If it’s cracked or degraded, purchase a replacement handle kit ($3–$8).

Step 7: Reassemble the Housing and Test

Now it’s time to put everything back together:

  1. Carefully place the recoil starter housing back onto the engine block, aligning the bolt holes.
  2. Insert all bolts and tighten them evenly with a socket wrench. Do not overtighten—just snug enough that the housing doesn’t move.
  3. Pull the cord handle slowly several times to ensure it retracts smoothly and doesn’t bind or jam.
  4. If the cord doesn’t retract fully, the spring may not be wound correctly. Remove the housing and rewind the cord in the opposite direction.
  5. Reconnect the spark plug wire and perform a test start (or dry-run pull if you’re not starting the engine yet).

Model-Specific Variations

Push Mowers vs. Self-Propelled Mowers

Push and self-propelled mowers are mechanically identical in terms of recoil starter design. The main difference is accessibility:

  • Push mowers: The recoil starter is usually on top of the engine, making it highly accessible. Most removals require only 2–4 bolts.
  • Self-propelled mowers: The recoil starter may be positioned differently to avoid the transmission or drive shaft. Check your manual for specific bolt locations.

Both use the same cord diameter and follow the same replacement steps.

Riding Mowers

Riding mowers typically have recoil starters mounted on the side of the engine for operator convenience. The replacement process is identical, but access may require:

  • Removing decorative shrouds or plastic covers around the engine.
  • Disconnecting the battery (on electric-start models) for safety.
  • Possible removal of the seat or fender for better workspace.

Always consult your riding mower’s manual before removal, as some models have unique mounting configurations.

Horizontal vs. Vertical Recoil Starters

Cord winding direction depends on your recoil starter orientation:

  • Horizontal starters: The pulley spins side-to-side. The cord typically winds clockwise or counterclockwise (check your old cord’s direction).
  • Vertical starters: The pulley spins front-to-back. Winding follows the same principle—match the old cord’s direction.

When in doubt, unwind a few inches of your old cord before removing the housing to observe its direction, then replicate this with the new cord.

Troubleshooting Common Issues

The Cord Won’t Retract Properly

Cause: The cord is wound too tightly or in the wrong direction.

Solution: Remove the housing, unwind the cord, and rewind it in the opposite direction. Ensure the wind is snug but not constrictive.

The Cord Slips or Unwinds During Use

Cause: The knot at the pulley anchor is not secure.

Solution: Remove the housing, re-tie the anchor knot with a figure-eight knot instead of an overhand knot, and pull very hard to test it before reassembly.

The Handle Knot Comes Loose

Cause: The knot is too small or not tight enough.

Solution: Tie a double overhand knot or a figure-eight knot at the handle end. These larger knots resist slipping better.

The Pulley Spins Freely but the Cord Doesn’t Unwind

Cause: The cord is wrapped around itself or bunched inside the housing.

Solution: Remove the housing and carefully unspool the cord, watching for loops or tangles. Rewind it in clean, overlapping layers.

When to Seek Professional Help

If you encounter any of these issues, professional repair may be needed:

  • The spring inside the housing is visibly damaged, cracked, or has lost tension.
  • The pulley is cracked or the anchor point is broken.
  • The engine still won’t start after cord replacement and spark plug check.
  • You feel uncomfortable working with the spring tension inside the housing.

A local lawn mower repair shop can complete a full recoil starter replacement (not just the cord) for $40–$80, including parts and labor.

Frequently Asked Questions

How often do lawn mower pull strings need replacement?

Pull strings typically last 3–5 seasons of regular mowing, depending on storage conditions and use frequency. UV exposure, moisture, and repeated pulling accelerate wear. Proper storage in a dry, shaded location extends cord life significantly.

Can you use regular rope or twine instead of specialty lawn mower cord?

No. Natural rope, cotton twine, and paracord lack the durability and tensile strength required. They will fray, stretch, or break under the repeated pulling force and the spring tension of the recoil mechanism. Always use braided nylon or polyester lawn mower cord rated for this application.

What’s the difference between 3mm, 3.5mm, and 4mm cord?

The diameter determines the cord’s tensile strength and the pulley’s compatibility. Using the wrong diameter can cause the cord to slip off the pulley or resist proper winding. Always match the diameter of the old cord or consult your mower’s manual. Most residential push mowers use 3.5mm.

Do I need to drain the fuel before replacing the pull string?

You don’t need to drain the fuel tank, but it’s good practice to allow the engine to cool completely and to disconnect the spark plug wire before working on the recoil starter. This prevents accidental engine ignition.

Can a broken pull string be repaired instead of replaced?

Minor fraying can be sealed with a lighter to temporarily extend the cord’s life, but a break in the middle of the cord cannot be reliably repaired. A splice or knot in the pull section will weaken the cord and create a potential catch point. Full replacement is safer and more cost-effective.