How to String a Self Feeding Weed Eater? Auto Feed Guide

Introduction

Weed eaters are one of the most versatile tools for maintaining a neat, tidy yard, cutting down overgrown grass, weeds, and edge vegetation that lawnmowers can’t reach. Among the most popular models on the market are self-feeding (also called auto feed) weed eaters, which automatically advance trimmer line as it wears down, eliminating the need to stop work and bump the tool on the ground to release more line. While these tools are designed for convenience, many homeowners struggle with restringing them correctly, leading to jams, poor cutting performance, and unnecessary wear on the tool. If you’ve ever wondered How to String a Self Feeding Weed Eater?, this comprehensive guide will walk you through the entire process, from understanding how the auto feed mechanism works to troubleshooting common issues, so you can keep your tool running smoothly for years.

• Introduction
• What Is a Self-Feeding Weed Eater?
• How the Self-Feeding Auto Feed Mechanism Works
• Safety Precautions for Restringing Your Weed Eater
• Tools and Materials You’ll Need for Stringing
• Step-by-Step Guide: How to String a Self Feeding Weed Eater?
• Auto Feed vs. Bump Feed Weed Eaters
• Tips and Best Practices for Extending Trimmer Line Life
• Common Mistakes to Avoid When Stringing a Self Feeding Weed Eater
• Troubleshooting Common Auto Feed Issues
• Frequently Asked Questions
• Conclusion

What Is a Self-Feeding Weed Eater?

A self-feeding weed eater, often referred to as an auto feed trimmer, is a type of string trimmer designed to automatically advance its cutting line as it wears down during use. Unlike traditional bump feed models, which require the user to tap the bottom of the tool on a hard surface to release a small amount of new line, auto feed trimmers use a built-in mechanism to push new line out without any manual input. This makes them ideal for users with large yards, commercial landscaping needs, or anyone who wants to avoid frequent interruptions during trimming sessions.

Auto feed weed eaters are available in gas-powered, corded electric, and cordless battery-powered models, and are sold by most major outdoor power equipment brands, including Stihl, Husqvarna, EGO, Ryobi, and Craftsman. They are slightly more expensive upfront than bump feed models, but many users find the convenience of automatic line advancement worth the extra cost, especially for frequent or heavy-duty use.

How the Self-Feeding Auto Feed Mechanism Works

To string a self-feeding weed eater correctly, it helps to understand how the auto feed mechanism functions, as improper loading is the most common cause of feed failures. The system has four core components that work together to advance line automatically:

• Trimmer line spool: A rotating plastic or metal spool that holds the coiled trimmer line. Most spools have small notches or holes in the center hub to secure the ends of the line during winding.
• Feed mechanism: A spring-loaded arm or small electric motor (on higher-end models) that pushes the line forward when the existing line wears down to a preset length. On spring-loaded models, the arm rests against the line as it spins, and releases to push new line out when the line is short enough to no longer make contact with the guard.
• Line guard: A metal or plastic cover that protects the feed mechanism from grass, dirt, and debris, and has small slots through which the line extends to cut vegetation.
• Spool housing: A removable cover that holds the spool and feed mechanism in place, and attaches to the main body of the weed eater.

When you turn on the weed eater, the spool spins, and the line wears down from contact with grass and weeds. As the line gets shorter, it no longer makes contact with the feed arm, triggering the mechanism to push a small amount of new line out through the guard slots. This process repeats continuously as you trim, so you never have to stop to advance the line manually.

Safety Precautions for Restringing Your Weed Eater

Restringing a weed eater is a simple task, but it comes with minor risks that can be easily avoided with basic safety precautions. Before you start the restringing process, keep these safety tips in mind:

• Always disconnect the power source before starting work. Accidental starting is the most common cause of injury while maintaining power equipment, so never skip this step, even if you are in a hurry.
• Wear work gloves and safety glasses at all times. Trimmer line is sharp enough to cut through skin, and small pieces of line or debris can cause eye injuries if they fly loose during the process.
• Work in a well-ventilated area if you are restringing a gas-powered model, to avoid inhaling fuel fumes.
• Keep children and pets away from your work area while you are restringing the tool, as small parts and sharp line can pose a hazard.
• Never work on the tool while it is running or connected to a power source, even if you are just making small adjustments.

Tools and Materials You’ll Need for Stringing

Before you start the restringing process, gather all the necessary tools and materials to avoid interruptions. Using the correct parts is critical for ensuring the auto feed mechanism works properly after you finish:

• Replacement trimmer line (check your owner’s manual for the exact diameter required for your model; most residential auto feed weed eaters use .080 or .095 inch round line, while heavy-duty models may require .105 inch line)
• Work gloves (to protect your hands from sharp line cuts)
• Safety glasses (to shield your eyes from flying debris and line fragments)
• Screwdriver (flathead or Phillips, depending on your model’s spool housing screws)
• Needle-nose pliers (to pull line through tight slots and adjust the spool)
• Wire cutters or heavy-duty scissors (to cut line to the correct length)
• Clean rag or small brush (to remove grass and dirt from the spool housing)
• Optional: Pre-wound replacement spool (available at most hardware stores for a quick, no-fuss replacement if you don’t want to wind the line yourself)
• Optional: Trimmer line lubricant (to reduce friction and extend the life of your line and feed mechanism)

Note that using the wrong line size is one of the most common causes of auto feed malfunction, so always verify the required diameter in your owner’s manual before purchasing replacement line.

Step-by-Step Guide: How to String a Self Feeding Weed Eater?

Once you have all your tools and materials ready, follow these steps to restring your self-feeding weed eater correctly. The entire process takes 10-15 minutes for most models, and no special technical skills are required.

1. Prep Your Weed Eater

First, disconnect the power source to prevent accidental starting while you work. For gas-powered models, turn off the fuel valve and disconnect the spark plug wire from the spark plug. For corded electric models, unplug the tool from the outlet. For cordless battery-powered models, remove the battery pack from the tool. Lay the weed eater on a flat, stable work surface, ideally on a mat or old towel to catch any debris or spilled fuel (for gas models). Use your clean rag or brush to remove all built-up grass, dirt, and debris from the spool housing, line guard, and feed slots. This prevents dirt from getting into the feed mechanism when you open the housing, which can cause jams later.

2. Remove the Old Spool

Locate the spool housing lock: most models have a small button, tab, or screw that secures the spool housing to the main body of the weed eater. Consult your owner’s manual if you cannot find the lock, as placement varies by brand and model. Release the lock, then twist the spool housing counterclockwise to remove it from the tool body. Pull the old spool out of the housing. If the old line is still attached to the spool, unwind it and discard it. Inspect the spool for cracks, warping, or broken parts: if the spool is damaged, replace it with a new one before installing new line, as a damaged spool will cause the auto feed mechanism to malfunction even if you load the line correctly.

3. Prepare the New Trimmer Line

Cut a length of replacement line equal to the length specified in your owner’s manual (most models require 10-15 feet of line, but check your model’s requirements to avoid overfilling or underfilling the spool). Fold the line in half to find the center point, so both ends are even. Locate the small notch or hole in the center of the spool hub: insert the folded end of the line into this notch, so the two cut ends are sticking out opposite each other. This ensures the line will unwind evenly from the spool as the auto feed mechanism advances it.

4. Wind the Line Onto the Spool

This is the most critical step for ensuring the auto feed mechanism works correctly. Hold the spool so the two line ends are pointing away from you. Wind each end of the line around the spool in the direction indicated by the arrows printed on the spool (nearly all spools have clear arrows showing the correct winding direction; winding the line backwards is the #1 cause of auto feed failure). Keep the line taut as you wind, and make sure the two lines do not cross over each other or overlap, as crossed line will catch on the spool and prevent smooth feeding. Wind until there is approximately 6 inches of line left on each end. Do not overfill the spool, as excess line will bunch up inside the housing and jam the feed mechanism.

5. Reassemble and Test the Weed Eater

Insert the wound spool back into the spool housing, making sure the two line ends are sticking out through the feed slots on the housing. Align the spool housing with the weed eater body, then twist it clockwise until it locks into place. Reconnect the power source: reattach the spark plug wire for gas models, plug in the cord for electric models, or reinsert the battery pack for cordless models. Turn on the weed eater and let it run for 10-15 seconds. You should see the auto feed mechanism advance the line slightly as it runs. If the line does not advance, turn off the tool immediately and double-check that you wound the line in the correct direction and that there are no jams in the feed slots. If the line feeds out too much at once, adjust the feed rate dial (if your model has one) per your owner’s manual instructions.

Auto Feed vs. Bump Feed Weed Eaters

If you are deciding between an auto feed (self-feeding) weed eater and a traditional bump feed model, it helps to compare their key features to determine which is right for your needs. The table below outlines the core differences between the two types:

For most users who trim frequently or have large properties, the convenience of an auto feed model outweighs the slightly higher upfront cost and restringing learning curve. For casual users who only trim their yard a few times a year, a bump feed model may be a more cost-effective option.

Tips and Best Practices for Extending Trimmer Line Life

Proper maintenance and usage habits will extend the life of your trimmer line and reduce the frequency with which you need to restring your self-feeding weed eater. Follow these tips to get the most out of your tool:

• Always use the trimmer line diameter recommended by your manufacturer. Using a thicker line than specified will overload the auto feed mechanism and cause premature wear, while a thinner line will slip and break frequently.
• Store unused trimmer line in a cool, dry place away from direct sunlight. UV exposure can make line brittle and prone to breaking, especially in warm climates.
• Avoid hitting hard objects like rocks, concrete, or tree trunks while trimming. Impact with hard surfaces will break the line instantly and can damage the spool and feed mechanism.
• Wipe down the spool housing and feed slots after each use to remove grass, dirt, and debris that can cause jams and wear on the feed mechanism.
• If you live in a humid climate, use trimmer line with a UV inhibitor coating to prevent it from becoming soft and gummy, which can cause it to tangle on the spool.
• If your model has an adjustable feed rate, set it to advance only a small amount of line at a time. Advancing too much line at once will waste line and increase the risk of jams.
• Replace the entire spool if you notice cracks, warping, or broken parts. A damaged spool will cause inconsistent line feeding and can damage the feed mechanism over time.

Common Mistakes to Avoid When Stringing a Self Feeding Weed Eater

Even experienced DIYers make mistakes when restringing auto feed weed eaters, leading to poor performance and unnecessary frustration. Avoid these common errors to ensure your tool works correctly the first time:

• Winding the line in the wrong direction: This is the most frequent cause of auto feed failure. If you wind the line backwards, the feed mechanism will not be able to push the line forward, and you will have to rewind the spool correctly. Always follow the arrows printed on the spool to ensure you wind in the right direction.
• Using the wrong trimmer line size: A line that is too thick will jam the feed mechanism, while a line that is too thin will slip and not advance properly. Always check your owner’s manual for the correct diameter before purchasing replacement line.
• Overfilling the spool: Excess line will bunch up inside the spool housing, causing jams and preventing the auto feed mechanism from working. Leave the recommended amount of slack (usually 6 inches per end) when winding, and do not force extra line onto the spool.
• Letting the line cross over itself while winding: Crossed line will catch on the spool and prevent smooth feeding, leading to uneven line advancement and frequent jams. Keep the two ends of the line opposite each other as you wind to avoid crossing.
• Skipping the cleaning step before restringing: Old grass, dirt, and debris left in the spool housing can get into the feed mechanism and cause jams, even if you load the new line correctly. Always wipe down the housing and feed slots before installing a new spool.
• Forgetting to reconnect the power source after reassembly: It’s easy to forget to plug in the cord, reattach the battery, or reconnect the spark plug after restringing, leading to frustration when the tool won’t turn on. Double-check the power connection before testing the tool.

Troubleshooting Common Auto Feed Issues

Even if you follow the restringing steps correctly, you may encounter occasional issues with your auto feed mechanism. The following are the most common problems and their solutions:

1. Line is not advancing automatically: First, confirm that you wound the line in the correct direction (refer to the arrows on the spool). If the direction is correct, remove the spool and clear any debris or jammed line from the feed slots using a small tool or compressed air. If the problem persists, check that the spool is seated correctly in the housing, and that the feed arm is not bent or broken. If the feed arm is damaged, replace it with a new part from the manufacturer.
2. Line is jamming frequently: This is usually caused by overfilling the spool, using the wrong line size, or debris in the feed mechanism. Empty the spool, clean the feed slots thoroughly, and reload the line using the correct size and winding direction, leaving the recommended amount of slack on each end.
3. Line is breaking frequently while trimming: First, confirm you are using the correct line size for your model. If the size is correct, inspect the spool for sharp edges or damage that may be cutting the line as it feeds out. Also, avoid hitting hard objects while trimming, as this is a common cause of frequent line breaks.
4. Line is feeding out unevenly, with one side longer than the other: This is almost always caused by the line crossing over itself while winding. Empty the spool and rewind the line, making sure the two ends stay opposite each other and do not cross at any point during winding.
5. Line is feeding out too much or too little at once: If your model has an adjustable feed rate dial, adjust it per your owner’s manual to increase or decrease the amount of line advanced per cycle. If your model does not have an adjustable setting, the feed mechanism spring may be worn out and need replacement.

Frequently Asked Questions

How often should I string my self-feeding weed eater?

There is no fixed schedule for restringing, as it depends on how frequently you use the tool and the thickness of the line you use. Most homeowners need to restring their weed eater every 2-4 months with regular use, or immediately if the line breaks or wears down to less than 3 inches long. If you notice the auto feed mechanism is working harder than usual to advance line, it’s a sign the spool is nearly empty and needs to be refilled.

Can I use any trimmer line in my self-feeding weed eater?

No, you should always use the trimmer line diameter recommended by your tool’s manufacturer. Most residential auto feed weed eaters use .080 or .095 inch round line, but some heavy-duty models require .105 inch line. Using a line that is too thick will jam the feed mechanism, while a line that is too thin will slip and not advance properly, leading to poor trimming performance and frequent line breaks.

Why is my self-feeding weed eater line not advancing?

The most common causes are incorrect line winding direction, a jammed feed mechanism, or a damaged spool. First, check that you wound the line in the direction indicated by the arrows on the spool – winding backwards is the most frequent cause of this issue. If the winding direction is correct, remove the spool and clear any debris or jammed line from the feed slots. If the problem persists, inspect the spool for cracks or warping, and check that the feed arm is not bent or broken.

Do I need to wear safety gear when restringing my weed eater?

Yes, it is highly recommended to wear work gloves and safety glasses when restringing your weed eater. Trimmer line is extremely sharp and can easily cut skin if it slips while you are winding it, and small pieces of line or debris can fly into your eyes during the process. Even if you are an experienced user, safety gear will prevent minor injuries that can occur unexpectedly.

Can I repair a broken auto feed mechanism?

In most cases, yes. Small replacement parts like the feed spring, feed arm, or line guide are available from most tool manufacturers, and can be installed with basic tools like a screwdriver and pliers. However, if the main housing of the feed mechanism is cracked or broken, it is usually more cost-effective to replace the entire spool housing assembly, as individual parts for the main housing are rarely sold separately. Consult your owner’s manual for part numbers and installation instructions for guidance.

Conclusion

Stringing a self-feeding weed eater is a simple, straightforward process that saves you money on replacement spools and ensures your tool performs at its best for years to come. By following the step-by-step guide outlined above, using the correct trimmer line size, and avoiding common mistakes like winding the line backwards or overfilling the spool, you can keep your auto feed weed eater running smoothly even with frequent use. Remember to perform regular maintenance, like cleaning the feed mechanism after each use and storing your line properly, to extend the life of both your line and your tool. If you run into issues with the auto feed mechanism, refer to the troubleshooting section above or consult your owner’s manual for model-specific guidance. Mastering How to String a Self Feeding Weed Eater? is a valuable skill for any homeowner or landscaper who wants to keep their yard looking neat without the hassle of frequent tool repairs or replacements.