How to Replace String on Craftsman Weed Eater? Step-by-Step

Introduction

Craftsman weed eaters are a popular choice for homeowners and landscapers alike, known for their durability and reliable performance. Over time, however, the trimmer string will wear down, fray, or break from regular use, cutting thick weeds, and contact with hard surfaces. Learning how to replace string on Craftsman weed eater is a simple, cost-effective maintenance task that you can complete at home in 15 to 30 minutes, no professional help required. This comprehensive guide will walk you through every step of the process, from identifying your trimmer head type to testing the newly installed string, along with tips for choosing the right replacement string, avoiding common mistakes, and troubleshooting issues that may arise after installation. Whether you have a bump feed, fixed line, or dual-line Craftsman trimmer, this guide has you covered.

• Understanding Your Craftsman Weed Eater Trimmer Head
• Tools and Materials Required for String Replacement
• Essential Safety Precautions to Follow
• Step-by-Step Guide to Replacing String on Craftsman Weed Eater
• How to Choose the Right Replacement String
• Tips for Extending Trimmer String Lifespan
• Common Mistakes to Avoid During Replacement
• Troubleshooting Issues After Replacement
• Frequently Asked Questions
• Conclusion

Understanding Your Craftsman Weed Eater Trimmer Head

Before you begin the replacement process, it is critical to identify which type of trimmer head your Craftsman weed eater uses, as the steps for replacing the string vary slightly between models. Craftsman manufactures three primary types of trimmer heads for its gas and electric weed eaters:

• Bump feed heads: The most common type found on consumer Craftsman weed eaters, these heads feature a bump mechanism that releases more string when you tap the bottom of the head against the ground while the trimmer is running. The string is stored on a rotating spool inside the head housing.
• Fixed line heads: These heads do not have a bump mechanism, and require you to manually extend the string when it wears down. The string is held in place on a stationary spool, and you will need to pull out the desired length and cut it with a blade built into the head housing.
• Dual-line heads: Designed for heavier-duty cutting, these heads use two parallel strands of string instead of one, allowing for faster and more efficient cutting of thick vegetation. They are available in both bump feed and fixed line configurations.

You can find the type of trimmer head your model uses by checking the owner’s manual, or by looking for a label on the bottom of the trimmer head itself. Knowing your head type will ensure you follow the correct replacement steps for your specific model.

Tools and Materials Required for String Replacement

Gathering all the necessary tools and materials before you start the replacement process will save you time and frustration. You will need the following items:

• Replacement trimmer string (correct diameter and type for your Craftsman model)
• Work gloves (to protect your hands from sharp string edges and debris)
• Safety glasses (to protect your eyes from flying grass and debris)
• Flathead screwdriver (to remove the retaining cap or bolt on most trimmer heads)
• Wire cutters or heavy-duty scissors (to cut the string to the correct length)
• Clean, dry rag (to wipe away grass and debris from the trimmer head housing)
• Optional: Light lubricant (to lubricate the spindle and bump mechanism for smooth operation)

Most of these items are likely already in your household toolbox, and replacement string is available at most hardware stores, home improvement centers, and online retailers for a low cost. Be sure to check your owner’s manual for the exact string diameter and length recommended for your specific Craftsman weed eater model to ensure optimal performance.

Essential Safety Precautions to Follow

While replacing trimmer string is a low-risk task, taking proper safety precautions will prevent injuries and damage to your trimmer. Follow these steps before you begin any work on your Craftsman weed eater:

1. Disconnect the spark plug wire: For gas-powered models, pull the spark plug wire off the spark plug to prevent the trimmer from starting accidentally while you are working on the head. For electric models, unplug the trimmer from the power outlet or remove the battery pack. This is the most important safety step, as even a seemingly off trimmer can start if the engine is bumped or the trigger is accidentally pressed.
2. Wear protective gear: Put on work gloves and safety glasses before handling the trimmer head or string. Sharp string edges can cause deep cuts, and grass or debris can fly into your eyes during handling or testing.
3. Work on a stable surface: Place the trimmer on a flat, level workbench or the ground in a well-lit area. This will prevent the trimmer from tipping over while you remove the head and spool.
4. Keep the work area clear: Ensure children and pets are kept away from the work area, and remove any tripping hazards like cords or tools from around your workspace.
5. Let a hot engine cool: If you were using the trimmer recently, wait at least 15 minutes for the engine and exhaust to cool down before handling the head to avoid burns.

Step-by-Step Guide to Replacing String on Craftsman Weed Eater

The exact steps for replacing string will vary slightly depending on your trimmer head type, but the core process is the same for all Craftsman models. Follow the steps below that match your head type for the best results.

Preparing the Trimmer Head for Replacement

These initial steps apply to all trimmer head types, and will make the replacement process much smoother:

1. Lay the trimmer on a flat surface with the trimmer head facing up. If your trimmer has a long shaft, you can rest the head on a block of wood to keep it steady.
2. Disconnect the spark plug wire or remove the battery pack, as outlined in the safety precautions section, to prevent accidental starting.
3. Rotate the trimmer head to locate the retaining cap or bolt that holds the spool in place. Most bump feed and dual-line heads use a twist-off retaining cap, while fixed line heads may use a small bolt secured with a screwdriver.
4. Remove the retaining cap by twisting it counterclockwise, or loosen the bolt with a flathead screwdriver, then set it aside in a safe place where it will not get lost.
5. Pull the spool straight out of the head housing. As you remove it, take note of how the string is wound and the direction of the winding – this is critical for ensuring the new string feeds correctly during use.
6. Use your clean rag to wipe away any grass, debris, or old string fragments from the inside of the head housing and the spindle. Buildup in the housing can cause the new string to jam or feed incorrectly.

Replacing String on Bump Feed Trimmer Heads

Bump feed heads are the most common type on Craftsman weed eaters, and the replacement process is straightforward:

1. Cut a length of replacement string that is 2 to 3 times the length of the old string you removed, plus an extra 6 inches to account for trimming after installation. For most Craftsman models, this works out to 10 to 12 feet of string.
2. Insert one end of the string into the small anchor hole on the spool, leaving about 2 inches of tail hanging out of the hole to secure it in place.
3. Wind the string tightly around the spool in the direction indicated by the arrow printed on the top of the spool (almost always clockwise when viewed from above). Wind evenly without overlapping the string, as overlaps will create bumps that prevent smooth feeding.
4. Leave about 6 inches of string hanging out of the winding area, then tuck the free end into the small notch on the edge of the spool to hold it in place while you install the spool.
5. Thread the free end of the string through the eyelet on the trimmer head housing, making sure it does not get caught on any rough edges or debris.
6. Slide the spool back into the head housing, aligning the notch on the spool with the spindle to ensure it seats properly.
7. Reattach the retaining cap by twisting it clockwise until it is snug, or tighten the bolt with your screwdriver to secure the spool in place. Do not overtighten, as this can damage the spool or head housing.
8. Pull the free end of the string firmly to release it from the notch on the spool. The string should slide out smoothly with no resistance.

Replacing String on Fixed Line Trimmer Heads

Fixed line heads do not have a bump mechanism, so you will need to manually extend the string when it wears down. The replacement process is similar to bump feed heads, with a few small differences:

1. Cut two equal lengths of replacement string, each 2 to 3 times the length of the old string, plus 6 inches extra. Most fixed line Craftsman heads use two strands of string for even cutting.
2. Insert one end of each string into the separate anchor holes on the spool, leaving 2-inch tails to hold them in place.
3. Wind each string tightly around its respective section of the spool in the correct direction (follow the arrow on the spool) without overlapping.
4. Leave 6 inches of string hanging out of each winding area, then tuck the free ends into the notches on the spool to hold them in place.
5. Thread each free end through the corresponding eyelet on the trimmer head housing.
6. Slide the spool back into the housing, align the notch with the spindle, and secure it with the retaining cap or bolt.
7. Pull both free ends firmly to release them from the notches, then trim them to equal length with your wire cutters. For fixed line heads, the ideal string length is 6 to 8 inches past the edge of the trimmer head.

Replacing String on Dual-Line Trimmer Heads

Dual-line heads are designed for heavy-duty cutting, and use two strands of string to cut through thick vegetation faster than single-line models. The replacement process is nearly identical to fixed line heads, with one key difference:

1. Cut two equal lengths of replacement string, each 2 to 3 times the length of the old string, plus 6 inches extra.
2. Insert one end of each string into the separate anchor holes on the dual spool, leaving 2-inch tails.
3. Wind each string tightly around its respective section of the spool in the direction indicated by the arrow on the spool, without overlapping the strands.
4. Leave 6 inches of string hanging out of each section, then tuck the ends into the notches on the spool.
5. Thread each free end through the corresponding eyelet on the trimmer head housing.
6. Slide the spool back into the housing, align the notch with the spindle, and secure it with the retaining cap or bolt.
7. Pull both free ends firmly to release them from the notches, then trim them to equal length. For dual-line bump feed models, you can bump the head to release more string as needed during use.

Reassembling and Testing the Trimmer

Once you have installed the new string on your spool, follow these steps to reassemble the trimmer and test it for proper operation:

1. Reconnect the spark plug wire to the spark plug, or reinsert the battery pack into your electric trimmer.
2. Place the trimmer on a flat, clear area away from plants, furniture, or people to test it.
3. Start the trimmer according to the instructions in your owner’s manual. For gas models, this may require priming the engine and pulling the starter cord.
4. Let the trimmer run for 30 seconds, then bump the head (for bump feed models) to release more string. Check that the string extends smoothly and cuts evenly.
5. If the string does not extend, turn off the trimmer immediately, disconnect the spark plug wire or remove the battery, and check that the string is wound in the correct direction and not jammed in the eyelet or head housing.
6. Trim any excess string to the recommended length (usually 6 to 8 inches past the edge of the trimmer head) for optimal cutting performance. Excess long string will put unnecessary strain on the trimmer’s motor and reduce efficiency.

How to Choose the Right Replacement String for Your Craftsman Weed Eater

Using the correct replacement string is essential for optimal performance and to avoid damaging your trimmer’s motor. There are three key factors to consider when selecting new string: diameter, material, and shape.

The diameter of the string is the most important specification, as a string that is too thick will overload the motor, while a string that is too thin will wear out quickly and break frequently. Most Craftsman weed eaters use either 0.080 inch or 0.095 inch diameter string, as outlined in your owner’s manual. The material of the string affects its durability: standard nylon string is suitable for light use, while polymer-coated nylon is more resistant to abrasion and lasts longer when cutting thick, woody vegetation. The shape of the string affects its cutting power: round string is standard for light grass and edging, while square or star-shaped string has sharper edges that cut through thick weeds and brush more effectively.

Below is a comparison of the most common trimmer string types to help you choose the best option for your needs:

While OEM Craftsman replacement string is available, most aftermarket string works equally well for residential use, as long as it meets the size and material requirements for your model. Aftermarket string is often more affordable, and many premium brands offer better durability than standard OEM options.

Tips for Extending Trimmer String Lifespan

With proper care and use, you can extend the life of your trimmer string and reduce the frequency of replacements. Follow these best practices to get the most out of your string:

• Avoid cutting against hard surfaces: Cutting against concrete, rocks, tree trunks, or curbs will wear down the string much faster than cutting grass and soft weeds. Try to keep the trimmer head a few inches above hard surfaces when edging.
• Maintain the correct string length: For bump feed models, keep the string trimmed to 6 to 8 inches past the edge of the head. String that is too long puts extra strain on the motor and wears out faster, while string that is too short reduces cutting efficiency.
• Store string properly: Keep unused replacement string in a cool, dry place away from direct sunlight. UV exposure can make nylon string brittle and prone to breaking.
• Clean the spool and head housing regularly: After each use, wipe away grass sap, dirt, and debris from the spool and head housing. Buildup can cause the string to jam and wear down faster.
• Use gentle bump motions for bump feed heads: Instead of slamming the head against the ground to release more string, use a light, quick tap. Rough handling can damage the bump mechanism and cause the string to feed incorrectly or break.

Common Mistakes to Avoid During Replacement

Even experienced DIYers can make mistakes when replacing trimmer string, leading to poor performance or damage to the trimmer. Avoid these common errors to ensure a smooth replacement process:

• Winding the string in the wrong direction: This is the most common mistake, and it will cause the string to jam when you try to bump the head on bump feed models. Always follow the arrow printed on the spool, and if no arrow is present, wind the string clockwise when viewed from the top of the spool.
• Overlapping the string while winding: Overlapping creates raised bumps on the spool that prevent the string from feeding smoothly. Wind the string tightly and evenly, with no gaps or overlaps between layers.
• Using string that is too thick: A string thicker than the recommended size for your model will overload the trimmer’s motor, causing it to overheat, lose power, or burn out prematurely. Always check your owner’s manual for the maximum allowed string diameter.
• Not leaving enough tail string: If you do not leave at least 2 inches of tail when inserting the string into the anchor hole, the string will slip out of the hole during use and cause a jam. Tuck the tail end securely into the anchor hole before winding.
• Forgetting to clean the head housing: Old grass, dirt, and string fragments left in the head housing can get caught in the new spool, causing jams and poor feeding. Always wipe the housing clean before installing the new spool.

Troubleshooting Common Issues After String Replacement

If you encounter issues after installing new string, you can usually fix the problem with a few simple adjustments. Here are the most common post-replacement issues and their solutions:

• String will not extend when bumping the head: First, check that the string is wound in the correct direction. If it is, disconnect the spark plug wire, remove the spool, and check that the free end of the string is not caught in the head housing or eyelet. Also ensure the spool is seated properly in the housing and the retaining cap is snug.
• String breaks frequently: This is usually caused by one of three issues: you are using string that is too thin for the vegetation you are cutting, you are winding the string too loosely on the spool, or you are cutting against hard surfaces. Switch to a thicker, more durable string, wind it tightly, and avoid contact with concrete, rocks, or tree trunks.
• Trimmer vibrates excessively: Excessive vibration is almost always caused by an unbalanced spool. Check that the string is trimmed to equal length on both sides (for dual-line models), and that the spool is secured tightly with the retaining cap or bolt. If the spool is damaged, replace it with a new one.
• String feeds out too quickly: This means the string is wound too loosely on the spool, or the bump mechanism is worn out. Rewind the string tightly, and if the problem persists, inspect the bump mechanism for damage and replace it if necessary.

Frequently Asked Questions

How often do I need to replace the string on my Craftsman weed eater?

The frequency of string replacement depends on how often you use the trimmer and the type of vegetation you are cutting. For light residential use (edging small lawns once a week), you will typically need to replace the string every 3 to 6 months. For heavy use (clearing thick weeds, brush, and overgrown areas weekly), you may need to replace it every 1 to 2 months. You will know it is time to replace the string when it becomes frayed, worn down to less than 3 inches in length, or breaks frequently during normal use.

What size string does my Craftsman weed eater use?

Most Craftsman weed eaters use either 0.080 inch or 0.095 inch diameter string. The exact size for your model is listed in the owner’s manual, which you can download for free from the official Craftsman website if you no longer have the physical copy. Using a string that is too thick will overload the motor, while a string that is too thin will wear out quickly and break often.

Can I use aftermarket string instead of OEM Craftsman string?

Yes, most aftermarket trimmer string works perfectly with Craftsman weed eaters, as long as it matches the recommended diameter and material for your specific model. Aftermarket string is often more affordable than official OEM Craftsman string, and many premium aftermarket brands offer equal or better durability than OEM options for residential and light commercial use.

Why does my new trimmer string keep breaking after replacement?

There are several common reasons for frequent string breakage after replacement: you are cutting against hard surfaces like concrete or rocks, you are using string that is too thin for the vegetation you are cutting, you wound the string too loosely on the spool, or the trimmer head is damaged and causing the string to snag. To fix this, use the correct string size for your model, wind it tightly and evenly, avoid cutting near hard surfaces, and inspect the head for damage or debris buildup.

How much string do I need to load into the spool?

As a general rule, cut a length of string that is 2 to 3 times the length of the old string you removed, plus an extra 6 inches to account for trimming after installation. For most Craftsman models, this works out to 10 to 15 feet of string per spool, but you can find the exact recommended amount in your owner’s manual for your specific model.

Conclusion

Learning how to replace string on Craftsman weed eater is a simple, valuable skill that will save you time and money on maintenance costs over the life of your trimmer. By following the step-by-step guide outlined in this article, identifying your trimmer head type, using the correct replacement string, and following safety precautions, you can complete the replacement process in minutes with no special tools or experience. Remember to avoid common mistakes like winding the string in the wrong direction or using the wrong string size, and follow the tips for extending string lifespan to reduce the frequency of replacements. With proper care and regular maintenance, your Craftsman weed eater will remain a reliable tool for keeping your lawn and yard looking neat for years to come.