How to Add String to Stihl Weed Eater? Bump Feed Advance

Introduction

Maintaining your Stihl weed eater is essential for keeping your lawn looking its best. One of the most important maintenance tasks is knowing how to add string to a Stihl weed eater properly. Whether you’re using a bump feed advance system or manual feed, understanding this process will save you time and money while ensuring optimal performance from your tool.

This comprehensive guide will walk you through everything you need to know about adding string to your Stihl weed eater, including step-by-step instructions, troubleshooting tips, and best practices to keep your equipment running smoothly.

Table of Contents

• Understanding Bump Feed Advance Systems
• Tools and Materials Needed
• Preparation Steps Before Adding String
• Step-by-Step Instructions for Adding String
• String Types and Sizes for Stihl Weed Eaters
• Common Mistakes to Avoid When Adding String
• Troubleshooting Common Issues
• Maintenance Tips and Best Practices
• When to Replace vs. Rewind String
• Comparison with Other Brands’ Systems
• Safety Considerations During String Replacement
• Professional Help vs. DIY String Replacement
• Frequently Asked Questions
• Conclusion

Understanding Bump Feed Advance Systems

Before diving into how to add string to a Stihl weed eater, it’s crucial to understand the bump feed advance mechanism. This system automatically feeds more line as needed during operation. When the existing string wears down, simply bumping the trimmer head against the ground releases additional line from the spool.

The bump feed system consists of several key components:

• The outer housing that protects the mechanism
• The inner spool that holds the string
• The spring-loaded tension mechanism
• The release button or lever for manual override

Understanding these components helps you appreciate why proper string installation is so important. If the string isn’t installed correctly, the bump feed mechanism won’t function properly, leading to frustration and potential damage to your equipment.

Tools and Materials Needed

While knowing how to add string to a Stihl weed eater doesn’t require specialized tools, having the right materials on hand makes the process much smoother. Here’s what you’ll need:

• Replacement string (specific to your model)
• Cleaning cloth or brush
• Small flathead screwdriver (optional)
• Work gloves for protection
• A clean, well-lit workspace

The most critical item is the correct replacement string. Stihl manufactures various string diameters and compositions depending on your specific weed eater model. Using the wrong type can cause feeding problems or damage to the trimmer head.

Preparation Steps Before Adding String

Proper preparation is essential when learning how to add string to a Stihl weed eater. Follow these preliminary steps to ensure success:

1. Disconnect the spark plug wire – This prevents accidental starting while you work on the trimmer head.
2. Clean the trimmer head – Remove any debris, grass clippings, or old string fragments that might interfere with the new installation.
3. Remove the existing string – If there’s old string remaining, carefully unwind it from the spool before installing new line.
4. Inspect the spool and housing – Check for cracks, worn springs, or damaged components that might affect performance.
5. Gather your materials – Have everything ready so you don’t have to search for items mid-process.

These preparation steps might seem routine, but they’re critical for ensuring your string replacement goes smoothly and lasts longer.

Step-by-Step Instructions for Adding String

Now let’s dive into the core of how to add string to a Stihl weed eater. Follow these detailed steps:

Removing the Trimmer Head

1. Locate the retaining mechanism on top of the trimmer head. Most Stihl models have either a push-button release or require removing a central nut.
2. Press the release button or use a wrench to loosen the nut, then lift the trimmer head straight up from the drive shaft.
3. Place the trimmer head on a clean, flat surface for easier access to the internal components.

Disassembling the Spool

1. Remove the outer housing by twisting or pulling it apart according to your model’s design.
2. Take out the inner spool that holds the string.
3. Clean both the spool and housing thoroughly to remove any debris or old string residue.

Installing New String

1. Cut approximately 10-15 feet of new string, depending on your trimmer head size.
2. Find the small hole in the center of the spool and thread one end of the string through it.
3. Hold the string end and begin winding the string around the spool in the direction indicated by arrows on the spool (usually clockwise).
4. Maintain consistent tension while winding to prevent loose coils that could tangle.
5. Continue winding until you’ve used most of the string, leaving about 6 inches unwound.
6. Thread the loose end through the hole in the trimmer head housing to secure it.

Reassembling the Trimmer Head

1. Place the spool back into the housing, ensuring it sits properly.
2. Reinstall the outer housing and secure it according to your model’s specifications.
3. Attach the trimmer head back onto the drive shaft and secure it with the retaining mechanism.
4. Reconnect the spark plug wire.

String Types and Sizes for Stihl Weed Eaters

Choosing the right string is fundamental to successfully answering how to add string to a Stihl weed eater. Stihl offers several string options:

Always check your owner’s manual for the recommended string specifications for your specific model. Using the wrong size can cause feeding problems or damage to the trimmer head mechanism.

Common Mistakes to Avoid When Adding String

Even experienced users sometimes make mistakes when learning how to add string to a Stihl weed eater. Here are the most common errors and how to avoid them:

Winding Direction Errors

One of the most frequent mistakes is winding the string in the wrong direction. Always follow the arrows printed on the spool. Winding against these arrows will cause the string to bind and fail to feed properly.

Inadequate Tension

If the string isn’t wound tightly enough, it will loosen during operation and tangle inside the trimmer head. Maintain consistent, firm pressure while winding to ensure proper tension.

Overfilling the Spool

While it might seem logical to pack as much string as possible, overfilling actually causes problems. Leave adequate space between the string and the housing to allow smooth feeding and prevent binding.

Using Wrong String Size

Using string that’s too thick or too thin for your model can cause feeding issues. Always verify the correct diameter before purchasing replacement string.

Troubleshooting Common Issues

Even after following proper procedures for how to add string to a Stihl weed eater, you might encounter some issues. Here’s how to address them:

String Won’t Feed Automatically

If your bump feed isn’t working after string replacement:

• Check that the string is threaded through the exit hole in the housing
• Verify the spool isn’t overfilled
• Ensure the string is wound in the correct direction
• Inspect the spring mechanism for proper tension

String Tangles Inside the Head

Tangling usually indicates improper winding technique:

• Remove the tangled string completely
• Clean the spool and housing thoroughly
• Rewind with consistent tension, following arrow directions
• Ensure even spacing between string layers

String Breaks Frequently

Frequent breakage suggests either:

• Using string that’s too thin for your application
• Sharp edges inside the trimmer head housing
• Excessive tension causing stress fractures

Consider upgrading to heavier-duty string or inspecting for sharp edges.

Maintenance Tips and Best Practices

Regular maintenance extends the life of your Stihl weed eater and reduces the frequency of string replacements. Follow these best practices:

Regular Inspection Schedule

Inspect your trimmer head weekly during heavy use periods:

• Check string length and condition
• Examine the spool for wear or damage
• Verify the bump feed mechanism operates smoothly
• Clean debris from the housing regularly

Proper Storage

Store your weed eater in a dry location away from direct sunlight. Moisture can cause string to degrade, while UV exposure weakens nylon fibers.

Seasonal Maintenance

At the beginning and end of each growing season:

• Completely disassemble and clean the trimmer head
• Replace old string entirely rather than adding new string over old
• Lubricate moving parts according to manufacturer specifications
• Inspect all components for wear or damage

When to Replace vs. Rewind String

Understanding when to replace versus rewind string is part of mastering how to add string to a Stihl weed eater:

Replace Entirely When:

• The string has become brittle or discolored
• You find yourself rewinding multiple times per season
• Different string types are needed for varying tasks
• The spool shows signs of wear or damage

Rewind When:

• The string simply ran out during normal use
• Only a small amount remains on an otherwise good spool
• The string is still in good condition but needs replenishing

As a general rule, if you’re spending more than 15 minutes trying to fix feeding issues, it’s often more cost-effective to replace the entire spool assembly.

Comparison with Other Brands’ Systems

Stihl’s bump feed advance system differs from other manufacturers in several ways:

Stihl’s system offers reliable performance but requires more attention to detail during string replacement compared to automatic systems. However, the bump feed gives you control over when additional line is deployed, which many users prefer for precision work.

Safety Considerations During String Replacement

Safety should always be your top priority when working on power equipment. Follow these guidelines when learning how to add string to a Stihl weed eater:

Before Starting Work

• Always disconnect the spark plug wire
• Ensure the engine is completely cool
• Work in a well-lit, clutter-free area
• Wear safety glasses to protect from debris

During the Process

• Never attempt string replacement while the engine is running
• Keep fingers away from moving parts
• Use tools rather than hands when possible
• Be aware that string can cause cuts if handled improperly

After Completion

• Test the trimmer head operation before full use
• Verify all components are properly secured
• Check that the spark plug wire is reconnected

Professional Help vs. DIY String Replacement

While learning how to add string to a Stihl weed eater is relatively straightforward, there are times when professional assistance is warranted:

When to Seek Professional Help:

• If you repeatedly experience feeding problems
• When internal components show signs of wear
• If the trimmer head won’t disassemble properly
• After multiple failed attempts at self-repair

DIY is Appropriate When:

• You have basic mechanical skills
• All components appear to be in good condition
• You’re simply replacing worn string
• You have access to your model’s instruction manual

The cost difference between DIY and professional service is significant – typically $5-10 for materials versus $30-50 for professional service. However, if you value your time or lack confidence in mechanical work, professional service may be worth the investment.

Frequently Asked Questions

How Often Should I Replace the String?

For average residential use, expect to replace or rewind string every 2-4 weeks during peak growing season. Heavy users might need to do this weekly. The key indicator is when you find yourself bumping the feeder more than twice per minute of operation.

Can I Use Generic String Instead of Stihl Brand?

Yes, many high-quality generic strings work well with Stihl trimmers. However, ensure you match the exact diameter specifications. Some users report better performance with Stihl-branded string, particularly in demanding conditions.

What Happens If I Put the String In Backwards?

Incorrect winding direction will cause the string to bind and not feed properly. You’ll likely need to completely remove and reinstall the string correctly. The arrows on the spool indicate the proper winding direction.

How Do I Know What Size String My Model Uses?

Check your owner’s manual first. If unavailable, measure the existing string or look up your model number online. Most Stihl weed eaters use .065″ to .080″ diameter string, but this varies by model.

Why Does My String Keep Breaking?

Several factors can cause frequent string breakage:

• String that’s too thin for your application
• Sharp obstacles in your trimming area
• Improper winding creating weak spots
• String that’s old or degraded

Can I Convert a Manual Feed to Bump Feed?

In most cases, yes. Stihl offers conversion kits for many models. However, check compatibility with your specific model number. The conversion typically involves replacing the trimmer head assembly.

Conclusion

Mastering how to add string to a Stihl weed eater is an essential skill that every owner should possess. While the process might seem intimidating at first, following the proper steps and understanding your equipment’s mechanics makes it manageable for most users.

Remember to always prioritize safety, use the correct string type for your model, and don’t hesitate to seek professional help when needed. Regular maintenance and proper string replacement techniques will keep your Stihl weed eater performing at its best season after season.

With practice, you’ll develop muscle memory for the process and be able to complete string replacements quickly and efficiently. This knowledge not only saves you money on service calls but also ensures minimal downtime when your trimmer needs attention. Keep this guide handy for reference, and soon adding string to your Stihl weed eater will become second nature.