The pull cord, also known as the starter cord, is a crucial component of lawn mowers that use a two-stroke or four-stroke engine. It is responsible for starting the engine by rotating the crankshaft, which ultimately leads to the combustion process. However, many lawn mower users have experienced the frustration of the pull cord jerking back, which can be both puzzling and annoying. In this article, we will delve into the possible reasons behind this phenomenon and explore the potential solutions to help you overcome this issue.
Understanding the Lawn Mower Pull Cord Mechanism
Before we dive into the causes of the pull cord jerking back, it is essential to understand the basic mechanism of the pull cord. The pull cord is connected to a pulley system that rotates the crankshaft when pulled. The crankshaft is then connected to the piston, which moves up and down to create the combustion process. The pull cord is designed to recoil back into the engine housing after it is pulled, which allows for repeated starting attempts.
Possible Causes of the Pull Cord Jerking Back
There are several reasons why the lawn mower pull cord may jerk back, and some of the most common causes include:
The engine is flooded, which means that there is too much fuel in the engine. This can cause the piston to hydrolock, resulting in the pull cord jerking back.
A faulty spark plug can also cause the pull cord to jerk back, as it can prevent the engine from firing properly.
A clogged air filter can reduce airflow to the engine, leading to poor combustion and causing the pull cord to jerk back.
A dirty or faulty carburetor can also cause the pull cord to jerk back, as it can prevent the proper mixture of fuel and air.
Engine-Related Issues
Engine-related issues are a common cause of the pull cord jerking back. Some of the possible engine-related causes include:
A low compression engine, which can make it difficult to start the engine, leading to the pull cord jerking back.
A faulty piston ring or cylinder wall, which can cause the engine to lose compression, resulting in the pull cord jerking back.
A worn-out or damaged crankshaft, which can cause the engine to vibrate excessively, leading to the pull cord jerking back.
Troubleshooting the Issue
If you are experiencing the issue of the pull cord jerking back, there are several troubleshooting steps you can take to identify and potentially resolve the problem. Always ensure you follow safety precautions when working with your lawn mower, including wearing protective gear and ensuring the mower is on a level surface.
One of the first steps is to check the engine for any blockages or debris that may be preventing it from starting properly. You can do this by removing the air filter and checking the carburetor for any signs of dirt or debris. You should also check the spark plug to ensure it is clean and functioning properly.
Checking the Pull Cord Mechanism
In addition to checking the engine, you should also inspect the pull cord mechanism to ensure it is functioning properly. Check the pull cord for any signs of wear or damage, and ensure it is properly attached to the pulley system. You should also check the pulley system for any signs of wear or damage, and ensure it is properly aligned.
If you find any issues with the pull cord mechanism, you can try to repair or replace it as needed. However, if you are not comfortable with DIY repairs, it is recommended to consult a professional small engine mechanic for assistance.
Preventative Maintenance
Preventative maintenance is key to preventing the pull cord from jerking back. Some of the preventative measures you can take include:
Regularly checking and cleaning the air filter to ensure proper airflow to the engine.
Regularly checking and maintaining the spark plug to ensure proper combustion.
Regularly checking and cleaning the carburetor to ensure proper fuel flow.
Regularly checking the pull cord mechanism to ensure it is functioning properly.
By following these preventative measures, you can help reduce the risk of the pull cord jerking back and ensure your lawn mower is running smoothly and efficiently.
Conclusion
In conclusion, the issue of the lawn mower pull cord jerking back can be caused by a variety of factors, including engine-related issues, a faulty pull cord mechanism, and poor maintenance. By understanding the possible causes and taking troubleshooting steps, you can potentially resolve the issue and get your lawn mower running smoothly again. Remember to always follow safety precautions when working with your lawn mower, and consult a professional if you are not comfortable with DIY repairs. By taking preventative measures and staying on top of maintenance, you can help reduce the risk of the pull cord jerking back and ensure your lawn mower is running at its best.
To further assist you in resolving the issue, the following table provides a summary of the possible causes and troubleshooting steps:
| Cause | Troubleshooting Steps |
|---|---|
| Engine flooded | Check and clean the air filter, check and maintain the spark plug, check and clean the carburetor |
| Faulty spark plug | Check and replace the spark plug as needed |
| Clogged air filter | Check and clean the air filter, replace as needed |
| Dirty or faulty carburetor | Check and clean the carburetor, replace as needed |
By following the troubleshooting steps and taking preventative measures, you can help resolve the issue of the lawn mower pull cord jerking back and ensure your lawn mower is running smoothly and efficiently.
What are the common causes of a lawn mower pull cord jerking back?
The lawn mower pull cord jerking back can be caused by several factors, including a faulty spark plug, incorrect ignition timing, or a malfunctioning flywheel. When the spark plug is dirty or worn out, it can cause the engine to misfire, leading to the pull cord jerking back. Similarly, if the ignition timing is not set correctly, it can disrupt the normal combustion process, resulting in the pull cord jerking back. A malfunctioning flywheel can also cause the pull cord to jerk back, as it can affect the engine’s ability to maintain a consistent speed.
To identify the cause of the problem, it’s essential to inspect the spark plug, ignition timing, and flywheel. Check the spark plug for any signs of wear or damage and replace it if necessary. Verify that the ignition timing is set correctly according to the manufacturer’s instructions. If the flywheel is damaged or worn out, it may need to be replaced. In some cases, the problem may be caused by a combination of these factors, so it’s crucial to perform a thorough inspection to determine the root cause of the issue.
How do I diagnose a faulty spark plug in my lawn mower?
Diagnosing a faulty spark plug in a lawn mower involves a few simple steps. First, remove the spark plug wire and boot from the spark plug. Next, use a spark tester to check for spark. If there is no spark, it could indicate a faulty spark plug. You can also use a multimeter to measure the resistance of the spark plug. A healthy spark plug should have a resistance of around 5,000 to 10,000 ohms. If the resistance is significantly higher or lower, it may indicate a faulty spark plug.
To further diagnose the issue, remove the spark plug and inspect it for any signs of wear or damage. Look for any deposits, corrosion, or signs of overheating. If the spark plug is dirty, you can try cleaning it with a spark plug cleaner. However, if the spark plug is damaged or worn out, it’s best to replace it with a new one. Make sure to use the correct type of spark plug recommended by the manufacturer, as using the wrong type can lead to further problems. By following these steps, you can determine whether a faulty spark plug is causing the pull cord to jerk back and take corrective action to fix the issue.
Can a clogged air filter cause the lawn mower pull cord to jerk back?
Yes, a clogged air filter can cause the lawn mower pull cord to jerk back. A clogged air filter can restrict airflow to the engine, leading to a rich fuel mixture that can cause the engine to misfire. When the engine misfires, it can cause the pull cord to jerk back. A clogged air filter can also cause the engine to run rough, leading to uneven combustion and further exacerbating the problem. In addition, a clogged air filter can cause the engine to overheat, leading to further problems, including premature wear on the engine and other components.
To fix the issue, it’s essential to inspect and clean or replace the air filter as needed. Check the air filter for any signs of dirt, debris, or damage. If the air filter is dirty, try cleaning it with compressed air or replacing it with a new one. Make sure to use the correct type of air filter recommended by the manufacturer, as using the wrong type can lead to further problems. By keeping the air filter clean and free of debris, you can ensure that the engine is getting the air it needs to run smoothly and prevent the pull cord from jerking back.
What role does the flywheel play in the lawn mower’s pull cord mechanism?
The flywheel plays a critical role in the lawn mower’s pull cord mechanism. The flywheel is responsible for storing energy from the pull cord and releasing it to the engine. When the pull cord is pulled, it turns the flywheel, which in turn generates a magnetic field that induces a voltage in the ignition coil. This voltage is then sent to the spark plug, which ignites the fuel mixture in the engine. If the flywheel is damaged or worn out, it can disrupt the normal operation of the pull cord mechanism, leading to the pull cord jerking back.
A faulty flywheel can cause the pull cord to jerk back due to the uneven transfer of energy to the engine. When the flywheel is damaged, it can cause the engine to misfire, leading to the pull cord jerking back. In addition, a faulty flywheel can also cause the engine to vibrate excessively, leading to further problems, including premature wear on the engine and other components. To fix the issue, it’s essential to inspect the flywheel for any signs of damage or wear and replace it if necessary. Make sure to use the correct type of flywheel recommended by the manufacturer, as using the wrong type can lead to further problems.
How do I prevent the lawn mower pull cord from jerking back in the future?
To prevent the lawn mower pull cord from jerking back in the future, it’s essential to perform regular maintenance on the lawn mower. This includes checking and replacing the spark plug, air filter, and flywheel as needed. Regularly inspect the pull cord and handle for any signs of wear or damage and replace them if necessary. It’s also essential to ensure that the ignition timing is set correctly and that the fuel mixture is correct. Additionally, make sure to use the correct type of fuel and oil recommended by the manufacturer, as using the wrong type can lead to further problems.
By following these tips, you can help prevent the pull cord from jerking back and ensure that your lawn mower runs smoothly and efficiently. Regular maintenance can also help extend the life of the lawn mower and prevent premature wear on the engine and other components. It’s also essential to follow the manufacturer’s instructions for maintenance and repair, as failure to do so can lead to further problems and even void the warranty. By taking the time to perform regular maintenance, you can ensure that your lawn mower runs well and that the pull cord does not jerk back.
Can a faulty ignition coil cause the lawn mower pull cord to jerk back?
Yes, a faulty ignition coil can cause the lawn mower pull cord to jerk back. The ignition coil is responsible for generating the high voltage needed to create a spark in the engine. When the ignition coil is faulty, it can disrupt the normal operation of the engine, leading to the pull cord jerking back. A faulty ignition coil can cause the engine to misfire, leading to uneven combustion and further exacerbating the problem. In addition, a faulty ignition coil can also cause the engine to run rough, leading to premature wear on the engine and other components.
To fix the issue, it’s essential to inspect the ignition coil for any signs of damage or wear and replace it if necessary. Check the ignition coil for any signs of cracking, corrosion, or wear and tear. Use a multimeter to measure the resistance of the ignition coil and compare it to the manufacturer’s specifications. If the resistance is out of range, it may indicate a faulty ignition coil. Make sure to use the correct type of ignition coil recommended by the manufacturer, as using the wrong type can lead to further problems. By replacing the faulty ignition coil, you can ensure that the engine runs smoothly and that the pull cord does not jerk back.