How to Load String in Stihl Weed Eater? Easy Spool Wind

Introduction

If you’ve ever owned a Stihl weed eater, you’ve likely faced the moment when the trimmer line snaps mid-job, leaving you with half-cut grass and a half-finished yard work task. Many Stihl owners assume they need to buy a pre-wound replacement spool from the hardware store, but learning How to Load String in Stihl Weed Eater? yourself is a simple, cost-effective skill that will save you time and money for years to come. Pre-wound spools often cost two to three times as much as bulk trimmer line, and loading your own spool takes less than 10 minutes once you know the process for your specific Stihl trimmer head model. This guide will walk you through every step of the process, from choosing the right string to avoiding common mistakes, so you can get back to trimming your lawn quickly and efficiently.

• Why Load Your Own Stihl Weed Eater String?
• Stihl Weed Eater Spool System Basics
• Choosing the Right Replacement String
• Tools and Materials You’ll Need
• Step-by-Step Guide to Loading String in a Stihl Weed Eater
• Loading an AutoCut Trimmer Head
• Loading a Fixed-Line Trimmer Head
• Loading a Loop-Load Trimmer Head
• Tips for Easy Spool Winding and Longevity
• Common Mistakes to Avoid When Loading String
• Troubleshooting Common Post-Load Issues
• Frequently Asked Questions
• How often should I replace the string on my Stihl weed eater?
• Can I use generic string in my Stihl trimmer?
• Why does my string keep jamming after I load it?
• What string diameter is best for a Stihl weed eater?
• Do I need to break in a new string after loading?
• Conclusion

Why Load Your Own Stihl Weed Eater String?

There are dozens of reasons to learn to load your own trimmer line instead of relying on pre-wound spools. The most obvious benefit is cost savings: a single pre-wound Stihl spool can cost $8 to $12, while a 50-foot roll of bulk Stihl-compatible trimmer line costs $5 to $7 and can be used to fill 3 to 4 spools. Over the course of a mowing season, this adds up to significant savings, especially if you have a large yard or use your weed eater frequently for commercial work.

Beyond cost, loading your own string gives you more control over the quality and type of line you use. Pre-wound spools often use generic, low-durability line that breaks easily when hitting rocks or thick weeds. When you load your own spool, you can choose a heavy-duty, serrated, or square-shaped line that is better suited to your specific yard conditions. You also avoid the frustration of running to the hardware store mid-yard work when your line snaps unexpectedly, since you likely have extra bulk line on hand already.

Finally, loading your own string is a quick skill that takes less than 15 minutes to master, even for first-time Stihl owners. Once you learn the process for your specific trimmer head, you’ll be able to replace a broken spool in minutes, with no need to wait for store hours or pay for pre-assembled parts.

Stihl Weed Eater Spool System Basics

Before you start loading string, it’s helpful to understand how Stihl’s spool system works. All Stihl weed eaters use a rotating spool housed inside the trimmer head that holds the trimmer line. As the weed eater runs, the spool rotates, feeding out small amounts of line as the existing line wears down from contact with grass, weeds, and hard surfaces. The spool is designed to hold a specific length and diameter of line, and loading it correctly ensures even feeding, minimal breakage, and smooth operation.

Stihl designs its trimmer heads to be user-serviceable, meaning you can open the head, remove the old spool, and load new line without special tools or professional help. The exact loading process varies slightly depending on the model of your Stihl trimmer head, but the core principles are the same across all models: wind the line evenly in the correct direction, secure the ends properly, and avoid overfilling the spool.

The three most common Stihl trimmer head models you’ll encounter are the AutoCut, fixed-line, and loop-load heads. The AutoCut is Stihl’s most popular model, designed to automatically advance line as it wears down, with a spool housed inside a twist-off cover. Fixed-line heads use a fixed length of line that does not advance automatically, requiring manual feeding when line breaks. Loop-load heads are an older model that uses a pre-cut length of line looped through the head, with no wound spool at all. Identifying your head model is the first step to learning How to Load String in Stihl Weed Eater? correctly, as the loading process for each model is distinct. You can find your head model printed on the bottom of the trimmer head cover, or in your Stihl weed eater’s user manual.

Choosing the Right Replacement String

Using the correct trimmer line for your Stihl weed eater is just as important as loading it correctly. The wrong line can cause frequent breakage, poor cutting performance, and even damage to your trimmer’s engine or gearbox. Stihl recommends using only Stihl-branded or Stihl-approved trimmer line, as generic line is often made of lower-quality plastic that wears down faster and breaks more easily.

When choosing string, you’ll need to select the correct diameter for your model. Stihl weed eaters support line diameters ranging from 0.065 inches to 0.095 inches, depending on the power of the model. Smaller, consumer-grade Stihl trimmers work best with 0.065-inch line, while larger, professional-grade models can handle 0.080 or 0.095-inch line for cutting thicker weeds and small saplings. Using a line that is too thick for your model will put excess strain on the engine, while line that is too thin will break frequently.

You’ll also need to choose a line shape that suits your yard conditions. Round line is the most common and works well for light grass and weeds. Square or star-shaped line has sharper edges that cut through thicker weeds and woody vegetation more effectively. Serrated line is designed for heavy-duty use, with small teeth that slice through tough plants with minimal effort.

To help you choose the right line for your needs, refer to the comparison table below of common Stihl-compatible trimmer string types:

For most users, Stihl-branded 0.080-inch line is the best all-around choice, as it balances cutting power and durability for most residential and light commercial use cases.

Tools and Materials You’ll Need

Loading string in a Stihl weed eater requires very few tools, and most of the items you need are likely already in your garage. Before you start, gather the following supplies:

• Replacement trimmer line (correct diameter and type for your Stihl model, as outlined in the previous section)
• A clean, flat workspace to work on (a workbench or even a clean section of your driveway works well)
• A pair of scissors or a sharp utility knife to cut the line to the correct length
• A small flathead screwdriver (optional, for prying off stubborn trimmer head covers)
• A clean rag (to wipe off any dirt or grass clippings from the trimmer head before disassembly)

You will not need any special Stihl-specific tools to load string in most models, as the trimmer heads are designed to be user-serviceable with basic household tools. If you have a Stihl model with a locking mechanism for the trimmer head, check your user manual to see if a special key is required to disassemble the head, though most models do not require this.

Step-by-Step Guide to Loading String in a Stihl Weed Eater

As mentioned earlier, the exact loading process varies depending on your Stihl trimmer head model. Below are step-by-step instructions for the three most common Stihl head types, so you can follow the guide that matches your model. No matter which head you have, the first step is always to disconnect the spark plug wire to prevent the weed eater from accidentally starting while you are working on it. This is a critical safety step that prevents serious injury.

Loading an AutoCut Trimmer Head

The AutoCut is Stihl’s most popular trimmer head, used on most consumer and mid-tier professional models. Follow these steps to load string in an AutoCut head:

1. Disconnect the spark plug wire from the spark plug to disable the engine. This prevents accidental startup while you work.
2. Turn the trimmer head upside down and locate the small arrow printed on the bottom of the spool cover. This arrow indicates the direction you need to wind the trimmer line.
3. Twist the spool cover counterclockwise (opposite the direction of the arrow) to remove it from the trimmer head. Set the cover aside in a safe place.
4. Pull the old, empty spool out of the trimmer head. If the spool is stuck, gently wiggle it back and forth to loosen it.
5. Cut a 10 to 12 foot length of your chosen trimmer line. For 0.065-inch line, use a 10-foot length; for 0.080-inch line, use 12 feet to ensure the spool is filled correctly.
6. Insert one end of the line into the small hole in the center of the spool. Push the line through until it emerges from the other side of the spool, then pull it tight so it is secured to the spool.
7. Wind the line around the spool in the direction indicated by the arrow on the bottom of the cover. Wind tightly and evenly, overlapping each layer slightly to avoid gaps. Do not overfill the spool: leave about 1/4 inch of space between the wound line and the edge of the spool.
8. Once the line is wound, tuck the loose end of the line into one of the small notches on the edge of the spool to hold it in place.
9. Insert the loaded spool back into the trimmer head, making sure it seats fully in the head.
10. Pull the loose end of the line out about 6 inches, then tuck it into the second notch on the spool. This will hold the line in place while you reattach the cover.
11. Twist the spool cover clockwise until it clicks into place, indicating it is fully secured.
12. Pull the loose end of the line firmly to release it from the notches, then reconnect the spark plug wire. Your weed eater is now ready to use.

Loading a Fixed-Line Trimmer Head

Fixed-line Stihl trimmer heads do not use a wound spool, so the loading process is much simpler. Follow these steps to load string in a fixed-line head:

1. Disconnect the spark plug wire to disable the engine, as with any trimmer maintenance task.
2. Locate the two small holes on the bottom of the trimmer head, one on each side of the head. These holes are used to thread the line through the head.
3. Cut a 10 to 15 foot length of trimmer line, depending on your head’s specifications (check your user manual for the exact recommended length).
4. Insert one end of the line into one of the holes, pushing it through until it emerges from the other side of the head.
5. Pull the line through until there is an equal length of line on both sides of the head.
6. Tie a secure double knot in the middle of the line, where it passes through the head. Pull the knot tight so it is seated against the bottom of the head, preventing the line from pulling through.
7. Trim the excess line on both sides so that 6 to 8 inches of line extends from each hole. This is the working length of the line that will cut grass and weeds.
8. Reconnect the spark plug wire. Your fixed-line trimmer is now ready to use. When the line wears down or breaks, simply pull out more line from the holes and trim it to the correct length, no need to re-thread the entire line.

Loading a Loop-Load Trimmer Head

Loop-load Stihl trimmer heads use a pre-cut length of line that is looped through the head, rather than wound around a spool. This design is simpler but requires a specific loading process. Follow these steps to load a loop-load head:

1. Disconnect the spark plug wire to disable the engine.
2. Locate the small loop of line already attached to the trimmer head, or cut a 12 to 18 inch length of trimmer line if you are replacing the entire line.
3. Fold the line in half to create a loop at one end.
4. Insert the loop through the small opening at the bottom of the trimmer head, pulling it through until the loop is seated inside the head.
5. Pull the two loose ends of the line through the loop, then pull tight to secure the line in place. This creates a secure knot that holds the line in the head.
6. Trim the loose ends of the line so that 6 to 8 inches extend from the bottom of the head, the standard working length for trimming.
7. Reconnect the spark plug wire. Your loop-load trimmer is now ready to use. When the line breaks, simply replace the entire length of line with a new pre-cut piece, following the same process.

Tips for Easy Spool Winding and Longevity

Once you know the basic loading process, these tips will help you wind spools more easily and extend the life of your trimmer line and weed eater:

• Wind in the correct direction: Always follow the arrow printed on the bottom of your trimmer head cover when winding line. Winding in the wrong direction will cause the line to tangle and not feed properly when you use the weed eater.
• Wind tightly and evenly: Avoid leaving gaps between layers of line as you wind, as gaps can cause the line to catch on itself and break. Wind firmly but do not stretch the line, as this can weaken the plastic and cause it to break more easily.
• Do not overfill the spool: Leave at least 1/4 inch of space between the top of the wound line and the edge of the spool. Overfilling will cause the line to jam in the trimmer head and can damage the spool or the trimmer’s gearbox.
• Use a winding tool if available: Some Stihl trimmer heads come with a small plastic winding tool that attaches to the spool, making it easier to wind line evenly without tangling. If your head came with this tool, use it for best results.
• Clean the trimmer head before loading: Wipe away any grass clippings, dirt, or old line debris from the spool and trimmer head before loading new line. Debris can cause the line to jam or feed unevenly.

Following these tips will make the loading process faster and easier, and will help your trimmer line last longer between replacements.

Common Mistakes to Avoid When Loading String

Even experienced Stihl owners make mistakes when loading trimmer line, leading to poor performance and frequent breakage. Avoid these common errors to ensure your weed eater runs smoothly after loading:

• Winding the line in the wrong direction: This is the most common mistake, and it will cause the line to tangle and not feed properly when you use the weed eater. Always check the arrow on the bottom of the spool cover before winding.
• Using line that is too thick for your model: As mentioned earlier, using a line diameter larger than what your Stihl model is rated for will put excess strain on the engine and gearbox, leading to premature wear and even engine damage. Always check your user manual for the maximum recommended line diameter for your model.
• Overfilling the spool: It may seem like more line will last longer, but overfilling causes the line to rub against the trimmer head cover, leading to jams and breakage. Stick to the recommended line length for your spool size.
• Not securing the line ends properly: Forgetting to tuck the loose end of the line into the spool notches (for AutoCut heads) or tie a secure knot (for fixed-line heads) will cause the line to come loose while you are trimming, requiring you to stop and reload.

Troubleshooting Common Post-Load Issues

Even if you load the string correctly, you may encounter minor issues when you first start using your weed eater. Here are solutions to the most common post-load problems:

• String breaks frequently: This is usually caused by using line that is too thin for your yard conditions, or winding the line too loosely on the spool. Try switching to a thicker or heavier-duty line, and wind the line more tightly on the spool to eliminate gaps.
• String will not advance automatically (AutoCut heads): This is almost always caused by winding the line in the wrong direction, or not leaving enough slack in the line when you reattach the cover. Rewind the spool in the correct direction, and make sure you pull 6 inches of line out before securing the cover.
• Line jams in the trimmer head: Jams are usually caused by overfilling the spool, or by debris (grass, dirt) getting caught in the head. Empty the spool, clean out the head, and reload with the correct amount of line, leaving 1/4 inch of space at the top of the spool.
• Weed eater smokes or runs poorly after loading: This is rarely caused by the line itself, and is usually a sign that you have overfilled the spool, causing excess friction in the head. Empty the spool and reload with less line, and the smoking should stop. If the problem persists, check that you are using the correct line diameter for your model.

Frequently Asked Questions

How often should I replace the string on my Stihl weed eater?

The frequency of string replacement depends on how often you use your weed eater and the conditions you trim in. For light residential use (trimming 1 to 2 times per month), you will need to replace the string every 2 to 3 months. For heavy commercial use (trimming daily), you may need to replace the string every 1 to 2 weeks. You will know it is time to replace the string when it breaks frequently, or when the working length of the line is less than 2 inches long.

Can I use generic string in my Stihl trimmer?

Yes, you can use generic trimmer line in your Stihl weed eater, as long as it is the correct diameter for your model. However, Stihl-branded line is made of higher-quality, UV-resistant plastic that lasts longer and breaks less frequently, especially in hot or sunny conditions. If you choose to use generic line, opt for a high-quality aftermarket brand rather than the cheapest option available, as low-quality generic line will break more often and cost you more money in the long run.

Why does my string keep jamming after I load it?

String jams are almost always caused by one of three issues: overfilling the spool, winding the line in the wrong direction, or using line that is too thick for your model. First, empty the spool and reload it with the correct amount of line, leaving 1/4 inch of space at the top of the spool. Make sure you wind the line in the direction of the arrow on the spool cover. If jams persist, check that you are using the correct line diameter for your Stihl model, as line that is too thick will not feed properly through the head.

What string diameter is best for a Stihl weed eater?

The best string diameter depends on your Stihl model and the conditions you trim in. For consumer-grade Stihl trimmers with engines smaller than 25cc, use 0.065-inch line for light grass and weeds. For mid-tier professional models with 25cc to 30cc engines, use 0.080-inch line for thicker weeds and overgrown grass. For professional-grade Stihl models with engines larger than 30cc, use 0.095-inch line for heavy brush and small saplings. Always check your user manual for the maximum recommended line diameter for your specific model to avoid damaging the engine.

Do I need to break in a new string after loading?

No, you do not need to break in new trimmer line after loading it. Stihl trimmer line is designed to be ready to use immediately after loading. However, you may notice that the line is slightly stiff when you first start using it, especially in cold weather. This is normal, and the line will become more flexible after a few minutes of use. There is no need to pre-stretch or treat the line before use.

Conclusion

Learning How to Load String in Stihl Weed Eater? is a simple, valuable skill that will save you time and money for as long as you own your Stihl trimmer. By choosing the right string for your model and following the correct loading process for your specific trimmer head, you can ensure smooth, consistent performance and avoid common issues like jams and frequent breakage. Remember to always disconnect the spark plug before working on your trimmer, wind the line in the correct direction, and avoid overfilling the spool to get the best results. With these tips and step-by-step instructions, you’ll be able to reload your Stihl weed eater in minutes, no professional help required.