String Won’t Pull on Lawn Mower (5 Expert Fixes for Jammed Cords)

Imagine this: It’s a crisp Saturday morning, the perfect day to finally tame that unruly lawn. You’re eager to get started, picturing the satisfying stripes you’ll leave behind. You grab your trusty lawn mower, give the cord a confident pull… and nothing. Absolutely nothing. The cord is jammed, refusing to budge. Frustration mounts as you envision your weekend plans slowly turning into a wrestling match with a stubborn machine.

Now, picture this instead: You approach your lawn mower with the same confidence, give the cord a pull, and the engine roars to life. You effortlessly glide across your lawn, the smell of fresh-cut grass filling the air. The sun is shining, and you’re enjoying the satisfaction of a job well done.

Why Won’t My Lawn Mower Cord Pull? Understanding the Problem

Before diving into the fixes, it’s crucial to understand the common culprits behind a jammed lawn mower cord. This will help you diagnose the problem accurately and choose the right solution. Here are the main reasons why your lawn mower cord might be stuck:

• Engine Seizure: This is often the most serious cause. Engine seizure happens when the internal components of the engine, like the piston and cylinder, become fused together due to a lack of lubrication, overheating, or corrosion.
• Bent Crankshaft: A bent crankshaft can also prevent the engine from turning over. This is often the result of hitting a solid object with the mower blade.
• Blade Obstruction: A lodged object, such as a rock, a piece of wood, or even excessive grass clippings, can jam the blade and prevent the engine from turning.
• Recoil Spring Issues: The recoil spring is responsible for retracting the starter cord after you pull it. If the spring is broken, damaged, or improperly wound, it can cause the cord to jam.
• Brake Engagement: Some lawn mowers have a safety feature that engages the brake when the handle is released. If this brake is stuck or improperly adjusted, it can prevent the engine from turning over.

Expert Fix #1: Clear Blade Obstructions

The Obvious First Step, Often Overlooked

This is the simplest and often most common reason for a jammed cord. Before you start tearing into your engine, take a good look under the mower deck.

My Experience: I once spent a frustrated hour troubleshooting a “seized” engine, only to discover a large tree root wedged firmly between the blade and the mower deck. A few minutes with a pry bar, and the mower was back in business.

How to Do It:

1. Safety First: Disconnect the spark plug wire. This is crucial to prevent accidental starting of the engine while you’re working on the blade.
2. Tilt the Mower: Carefully tilt the mower on its side (carburetor side up to prevent fuel from flooding the engine).
3. Inspect the Blade: Look for any obstructions around the blade. Common culprits include rocks, sticks, clumps of grass, and even small toys.
4. Remove Obstructions: Use gloves and a sturdy tool (like a pry bar or a screwdriver) to carefully remove any obstructions.
5. Test the Blade: Once the obstructions are removed, try turning the blade by hand. It should rotate freely.
6. Reconnect and Test: Reconnect the spark plug wire and try pulling the starter cord.

Data Point: According to a study by the Outdoor Power Equipment Institute (OPEI), blade obstructions are the cause of approximately 30% of lawn mower starting problems.

Actionable Advice: After each mowing session, take a minute to clean the underside of your mower deck. This will prevent the buildup of grass clippings and other debris that can cause obstructions.

Expert Fix #2: Inspect and Repair the Recoil Starter

The Heart of the Pull-Start System

The recoil starter is the mechanism that allows you to start the engine by pulling the cord. It consists of a pulley, a spring, and a rope. If any of these components are damaged, the cord can jam.

My Experience: I once inherited an old lawn mower that had been sitting in a shed for years. The cord was completely stuck. After disassembling the recoil starter, I found that the spring was rusted and broken. Replacing the spring brought the mower back to life.

How to Do It:

1. Safety First: Disconnect the spark plug wire.
2. Remove the Recoil Starter Cover: This is usually held in place by a few screws.
3. Inspect the Cord: Check the cord for any signs of wear, fraying, or breakage. If the cord is damaged, replace it.
4. Inspect the Pulley: Make sure the pulley rotates freely. If it’s sticking, try lubricating it with a silicone-based lubricant.
5. Inspect the Spring: This is the most common culprit. Look for any signs of rust, breakage, or damage. If the spring is damaged, replace it. Be extremely careful when handling the spring, as it can be under tension.
6. Reassemble the Recoil Starter: Carefully reassemble the recoil starter, making sure the spring is properly wound. This can be tricky, so it’s helpful to consult a repair manual or watch a video tutorial.
7. Test the Recoil Starter: Before reinstalling the recoil starter on the mower, test it to make sure the cord retracts smoothly.
8. Reinstall and Test: Reinstall the recoil starter on the mower and try pulling the starter cord.

Data Point: A survey of small engine repair shops found that recoil starter problems account for approximately 25% of lawn mower repairs.

Actionable Advice: When replacing the recoil spring, wear safety glasses to protect your eyes. The spring can snap unexpectedly and cause injury.

Expert Fix #3: Check for Brake Engagement Issues

A Safety Feature Gone Wrong

Some lawn mowers have a safety feature that engages the brake when the handle is released. This prevents the blade from spinning when you’re not holding the handle. If this brake is stuck or improperly adjusted, it can prevent the engine from turning over.

My Experience: My neighbor was convinced his lawn mower engine was seized. After a quick inspection, I noticed the brake lever was slightly engaged, even when he was holding the handle. A simple adjustment of the brake cable solved the problem.

How to Do It:

1. Safety First: Disconnect the spark plug wire.
2. Locate the Brake Mechanism: This is usually located near the handle.
3. Inspect the Brake Cable: Check the brake cable for any signs of damage or fraying.
4. Adjust the Brake Cable: If the brake cable is too tight, it can prevent the engine from turning over. Loosen the cable slightly by adjusting the cable tensioner.
5. Lubricate the Brake Mechanism: Use a silicone-based lubricant to lubricate the brake mechanism. This will help it move freely.
6. Test the Brake: Make sure the brake engages properly when you release the handle and disengages when you hold the handle.
7. Reconnect and Test: Reconnect the spark plug wire and try pulling the starter cord.

Data Point: Brake engagement issues are more common in older lawn mowers or mowers that have been stored for a long period of time.

Actionable Advice: Regularly inspect and lubricate the brake mechanism to prevent it from sticking.

Expert Fix #4: Diagnose and Address Engine Seizure

The Most Serious Problem

Engine seizure is a serious problem that can be caused by a lack of lubrication, overheating, or corrosion. If you suspect engine seizure, it’s important to diagnose the problem accurately and take appropriate action.

My Experience: I once bought a used lawn mower that had been sitting in a barn for years. The engine was completely seized. After disassembling the engine, I found that the piston was rusted and fused to the cylinder wall. I was able to free the piston by soaking it in penetrating oil for several days, but the engine ultimately needed a complete rebuild.

How to Do It:

1. Check the Oil Level: Make sure the oil level is at the proper level. Low oil can cause engine seizure.
2. Smell the Oil: If the oil smells burnt or has a metallic odor, it may be a sign of engine damage.
3. Try Turning the Blade: If you can’t turn the blade by hand, it’s a strong indication of engine seizure.
4. Remove the Spark Plug: Removing the spark plug can sometimes relieve pressure in the cylinder and allow you to turn the blade.
5. Check for Rust: Look for signs of rust or corrosion inside the cylinder.
6. Apply Penetrating Oil: If you suspect engine seizure, try applying penetrating oil to the cylinder. Let the oil soak for several days, then try turning the blade again.
7. Disassemble the Engine: If penetrating oil doesn’t work, you may need to disassemble the engine to inspect the internal components. This is a complex task that requires specialized tools and knowledge.
8. Engine Rebuild or Replacement: Depending on the extent of the damage, you may need to rebuild the engine or replace it entirely.

Data Point: Engine seizure is more common in lawn mowers that are not properly maintained or that are used in harsh conditions.

Actionable Advice: Change the oil regularly according to the manufacturer’s recommendations. This will help prevent engine seizure.

Expert Fix #5: Identify and Rectify a Bent Crankshaft

The Result of a Hard Impact

A bent crankshaft is often the result of hitting a solid object with the mower blade. This can prevent the engine from turning over and cause the cord to jam.

My Experience: I once saw a lawn mower that had been used to mow over a hidden stump. The blade was badly damaged, and the crankshaft was visibly bent. The owner had to replace the entire engine.

How to Do It:

1. Inspect the Blade Adapter: Remove the blade and inspect the blade adapter for any signs of damage or bending.
2. Check for Wobbling: With the blade removed, try turning the crankshaft by hand. If it wobbles or feels uneven, it may be bent.
3. Use a Dial Indicator: A dial indicator can be used to measure the runout of the crankshaft. This will give you a precise measurement of how much the crankshaft is bent.
4. Crankshaft Straightening (Rare): In some cases, a bent crankshaft can be straightened by a professional machinist. However, this is a complex and expensive process.
5. Engine Replacement: In most cases, a bent crankshaft requires engine replacement.

Data Point: A bent crankshaft is a common cause of lawn mower engine failure, especially in areas with rocky or uneven terrain.

Actionable Advice: Be careful when mowing in areas with rocks, roots, or other obstacles. Avoid hitting solid objects with the mower blade.

Preventative Maintenance: Keeping Your Lawn Mower Running Smoothly

The best way to avoid a jammed lawn mower cord is to perform regular preventative maintenance. Here are some tips:

• Change the Oil Regularly: This is the most important thing you can do to keep your engine running smoothly. Follow the manufacturer’s recommendations for oil change intervals. I generally recommend changing the oil after every 25 hours of use or at least once a year.
• Clean the Air Filter: A dirty air filter can restrict airflow to the engine, causing it to run poorly. Clean the air filter regularly, or replace it if it’s damaged.
• Sharpen the Blade: A dull blade can put extra strain on the engine and cause it to overheat. Sharpen the blade regularly to keep it cutting efficiently.
• Clean the Underside of the Deck: As mentioned earlier, cleaning the underside of the deck after each mowing session will prevent the buildup of grass clippings and other debris that can cause obstructions.
• Store the Mower Properly: When storing the mower for the winter, drain the fuel tank and carburetor to prevent fuel from gumming up the engine. I add a fuel stabilizer to my gas can, which I use in all my small engines (chainsaws, trimmers, etc.). This prevents fuel degradation and makes starting much easier in the spring.
• Inspect the Spark Plug: Check the spark plug regularly for signs of wear or fouling. Replace the spark plug if necessary.

The Woodworking Connection: Parallels in Tool Maintenance

My experience with lawn mowers extends beyond just grass cutting.

Chainsaw Maintenance: Just like a lawn mower, a chainsaw relies on a properly functioning engine. Regular maintenance, including cleaning the air filter, changing the spark plug, and ensuring proper lubrication, is crucial. The fuel used in chainsaws is just as susceptible to going stale as lawn mower fuel, so I always use fuel stabilizer.

Wood Chipper Maintenance: Wood chippers, often powered by gasoline engines, face similar challenges. Keeping the blades sharp is paramount for efficient chipping, just as a sharp mower blade is essential for a clean cut. Regular oil changes and air filter cleaning are also vital for maintaining engine performance.

The Importance of Sharp Blades: In both lawn mowers and woodworking tools, sharp blades are key to efficiency and safety. A dull lawn mower blade tears the grass, leaving it susceptible to disease. A dull chainsaw blade requires more force, increasing the risk of kickback. I always sharpen my blades regularly and replace them when necessary.

Firewood Preparation: A Tangential Tale

Speaking of woodworking, let’s veer slightly into firewood preparation. While seemingly unrelated to a jammed lawn mower cord, the principles of tool maintenance and engine care apply equally to equipment like log splitters and chainsaws used in firewood processing.

Log Splitters: Many log splitters are powered by gasoline engines. Proper maintenance, including oil changes, air filter cleaning, and fuel stabilization, is crucial for reliable operation. Hydraulic fluid levels also need to be checked and maintained.

Chainsaws in Firewood Processing: Chainsaws are indispensable for felling trees and cutting logs into firewood lengths. Maintaining a sharp chain, cleaning the air filter, and ensuring proper lubrication are essential for safe and efficient operation.

Seasoning Firewood: While not directly related to engine maintenance, proper firewood seasoning is crucial for efficient burning. Seasoning reduces the moisture content of the wood, making it easier to ignite and burn cleanly. I aim for a moisture content of around 20% before burning firewood.

Data Point: Seasoned firewood can have up to 25% more heat output than unseasoned firewood.

Troubleshooting Beyond the Basics: When to Call a Professional

While I’ve covered the most common causes and fixes for a jammed lawn mower cord, there are times when it’s best to call a professional. If you’re not comfortable working on small engines, or if you’ve tried the fixes I’ve described and the cord is still jammed, it’s time to seek expert help.

Signs You Need a Professional:

• You’re Not Comfortable Working on Small Engines: Small engine repair can be complex and requires specialized tools and knowledge. If you’re not comfortable with this type of work, it’s best to leave it to a professional.
• You’ve Tried the Fixes and the Cord is Still Jammed: If you’ve tried the fixes I’ve described and the cord is still jammed, it’s likely that there’s a more serious problem that requires professional attention.
• The Engine is Making Strange Noises: Unusual noises, such as knocking, grinding, or squealing, can indicate serious engine damage.
• You Suspect Internal Engine Damage: If you suspect that the engine has suffered internal damage, such as a broken connecting rod or a cracked cylinder, it’s best to have it inspected by a professional.

Final Thoughts: A Smooth Start to Your Lawn Care

A jammed lawn mower cord can be frustrating, but it’s usually a sign of a problem that can be fixed. By understanding the common causes of a jammed cord and following the expert fixes I’ve described, you can get your lawn mower back in action and enjoy a smooth start to your lawn care routine. Remember, preventative maintenance is key to avoiding these problems in the first place.

So, the next time your lawn mower cord refuses to pull, don’t despair. Take a deep breath, troubleshoot the problem systematically, and apply the appropriate fix. With a little knowledge and effort, you can conquer that stubborn cord and get back to enjoying your well-manicured lawn. And who knows, you might even discover a newfound appreciation for the inner workings of small engines!

Learn more