How to Remove Stihl Weed Eater String? Old String Removal

Introduction

Removing the old cutting line from a Stihl weed eater is a routine maintenance task that keeps the trimmer running efficiently and prevents damage to the head. Whether you are preparing to install fresh line or simply clearing a jam, knowing how to remove Stihl weed eater string correctly saves time and protects the tool. This guide covers every major Stihl trimmer head design, the tools you need, safety steps, and a detailed walk‑through for each head type. By the end you will be able to clear old line confidently and get back to clean edges in your yard.

• Understanding Stihl Weed Eater String Types
• Tools and Materials
• Safety Precautions
• Step-by-Step Removal Process
• Removing String from Bump‑Feed Head
• Removing String from Fixed‑Line Head
• Removing String from Auto‑Feed Head
• Cleaning and Inspecting the Trimmer Head
• Comparison Table of Stihl Trimmer Heads
• Tips and Best Practices
• Common Mistakes to Avoid
• Frequently Asked Questions
• Conclusion

Understanding Stihl Weed Eater String Types

Stihl offers several trimmer head designs, each with a slightly different line‑loading mechanism. The most common are the bump‑feed (or tap‑feed) head, the fixed‑line head, and the auto‑feed head. Bump‑feed heads release line when you tap the head on the ground, fixed‑line heads require manual threading of a pre‑cut length, and auto‑feed heads advance line automatically as it wears. Knowing which head you have determines the exact removal steps. All Stihl heads share a central spool that holds the line, a retaining cap or knob, and a spring‑loaded mechanism that controls line release. The line itself comes in various diameters (typically 0.065 in to 0.095 in) and shapes (round, square, twisted) to match cutting conditions.

Tools and Materials

Before you start, gather the following items so the job proceeds without interruptions:

• Protective gloves and safety glasses
• Adjustable wrench or the specific Stihl head‑nut wrench (often 13 mm)
• Flat‑head screwdriver (for heads with a retaining screw)
• Clean rag or shop towel
• Small brush (old toothbrush works well) for debris removal
• Replacement trimmer line (matching the diameter and shape recommended for your model)
• Owner’s manual for torque specifications and head‑specific diagrams

Having the correct wrench prevents rounding the head nut, and the manual ensures you follow any model‑specific release procedures.

Safety Precautions

Safety is paramount when working on any power equipment. Follow these steps before touching the trimmer head:

1. Turn off the engine and disconnect the spark plug wire (or remove the battery on cordless models).
2. Allow the engine to cool completely; hot components can cause burns.
3. Wear gloves to protect your hands from sharp line ends and any residual debris.
4. Secure the trimmer on a stable workbench or hold it firmly with the shaft pointing away from you.
5. Keep the work area clear of bystanders, pets, and flammable materials.

These precautions eliminate the risk of accidental starts and protect you from injury while you manipulate the head.

Step-by-Step Removal Process

The overall removal workflow is similar across head types, but the details differ. The high‑level steps are:

1. Remove the retaining cap or knob that secures the spool.
2. Extract the spool from the head housing.
3. Unwind or cut the old line from the spool.
4. Clean the spool and housing of grass, dirt, and old line fragments.
5. Inspect the spool, spring, and eyelets for wear or damage.
6. Reassemble the head (or proceed to install new line).

Each of the following sections expands the relevant sub‑steps for the three main head designs.

Removing String from Bump‑Feed Head

Bump‑feed heads are the most common on Stihl trimmers. They typically use a two‑piece spool held by a central nut.

1. Locate the central retaining nut on the bottom of the head. Using the appropriate wrench, turn the nut counter‑clockwise until it loosens. Some models have a left‑hand thread; check the manual if the nut does not turn easily.
2. Lift the outer cover off the spool. The spool may stay attached to the inner hub; if so, pull the spool straight out.
3. Observe how the line is wound. Most bump‑feed spools have two separate channels. Unwind the line by hand, or cut it with scissors if it is tangled.
4. Remove any remaining line fragments from the eyelets. Use the small brush to clear grass clippings from the spool channels and the head housing.
5. Inspect the spring located under the spool. If the spring is stretched or broken, replace it before reloading new line.
6. Reinstall the spool, align the cover, and tighten the retaining nut to the torque specified in the manual (usually 8–10 Nm).

After removal, you are ready to load fresh line following the manufacturer’s winding direction arrows.

Removing String from Fixed‑Line Head

Fixed‑line heads do not have a bump mechanism; the line is threaded through a single eyelet and held by a set screw or a simple friction fit.

1. Identify the set screw on the side of the head. Loosen it with a flat‑head screwdriver just enough to release tension on the line.
2. Pull the old line out of the eyelet. If the line is knotted, cut the knot with scissors and pull the remainder through.
3. Slide the spool (if present) out of the housing. Some fixed heads have a removable spool; others integrate the spool into the head body.
4. Clean the eyelet and any internal channels with the brush and rag.
5. Check the set screw threads for damage. Replace the screw if it is stripped.
6. Reassemble by inserting the spool (if applicable), threading new line, and tightening the set screw securely.

Because there is no spring, the fixed‑line head is simpler but requires precise line length for optimal performance.

Removing String from Auto‑Feed Head

Auto‑feed heads advance line automatically via a centrifugal mechanism. They often have a sealed spool that must be opened for line replacement.

1. Remove the head from the trimmer shaft by loosening the head‑mounting bolt (usually a 13 mm bolt). Set the head on a clean surface.
2. Locate the spool release tabs on the side of the head. Press both tabs simultaneously and lift the spool cover off.
3. The spool will now be exposed. Pull the spool out of the housing.
4. Unwind the old line from the spool. Auto‑feed spools often have a single channel; follow the winding direction indicated on the spool.
5. Clean the spool, the feed mechanism, and the housing interior. Pay special attention to the centrifugal pawls; they must move freely.
6. Inspect the pawls and spring for wear. Replace any damaged parts before reloading.
7. Reinstall the spool, snap the cover back onto the tabs, and remount the head onto the shaft, tightening the mounting bolt to the specified torque.

Auto‑feed heads are convenient but require careful cleaning of the feed mechanism to avoid jams.

Cleaning and Inspecting the Trimmer Head

Regardless of head type, thorough cleaning extends the life of the trimmer. After removing the old line:

• Use the brush to dislodge grass, dirt, and sand from all crevices.
• Wipe the housing and spool with a rag dampened with a mild solvent (e.g., isopropyl alcohol) to remove oily residue.
• Check the eyelets for sharp edges or deformation; file smooth if necessary.
• Examine the spring (bump‑feed and auto‑feed) for corrosion or loss of tension.
• Verify that the retaining nut, set screw, or mounting bolt threads are clean and undamaged.

Replacing worn components now prevents future line‑feeding problems and reduces vibration during operation.

Comparison Table of Stihl Trimmer Heads

This table helps you identify which head you have and sets expectations for line capacity and removal effort.

Tips and Best Practices

• Always use the line diameter recommended for your specific Stihl model; oversized line can jam the head, undersized line wears quickly.
• Wind the new line in the direction indicated by arrows on the spool; reverse winding causes feeding failures.
• Keep a spare spool and a few pre‑cut lengths of line in your tool kit for quick field changes.
• Lubricate the head’s spring and pawls lightly with a silicone‑based spray during annual maintenance.
• Store the trimmer with the head removed or the line retracted to avoid UV degradation of the line.
• When re‑installing the retaining nut, hand‑tighten first, then torque to spec to avoid cross‑threading.

Following these habits reduces downtime and keeps the trimmer cutting cleanly.

Common Mistakes to Avoid

• Forcing the retaining nut: Applying excessive force can strip the threads or crack the head housing. Use the correct wrench and steady pressure.
• Ignoring the winding direction: Loading line opposite to the arrow leads to immediate feed problems and wasted line.
• Skipping cleaning: Residual grass and dirt cause the line to bind, especially in auto‑feed mechanisms.
• Using mismatched line diameter: Too thick a line stresses the motor; too thin a line breaks under load.
• Neglecting spring inspection: A worn spring in bump‑feed heads results in inconsistent line release.
• Reassembling without checking torque: Loose nuts or bolts vibrate loose during operation, risking head detachment.

Avoiding these pitfalls ensures a smooth line‑change experience and prolongs the life of your Stihl trimmer.

Frequently Asked Questions

How often should I replace the trimmer line?

Replace the line whenever it becomes worn down to less than half its original diameter, shows fraying, or fails to feed properly. For typical residential use, this is every 2–4 weeks during the growing season.

Can I use any brand of line in my Stihl trimmer?

You can use other brands as long as the diameter, shape, and material match Stihl’s specifications for your model. Using the correct specs is more important than the brand name.

Why does my bump‑feed head not release line when I tap it?

Common causes include a worn or broken spring, line wound in the wrong direction, or debris jamming the spool. Clean the head, verify winding direction, and inspect the spring.

Is it necessary to remove the head from the shaft for line removal?

For bump‑feed and fixed‑line heads you can usually service the spool while the head remains on the shaft. Auto‑feed heads often require removal to access the spool cover tabs.

What should I do if the retaining nut is stuck?

Apply penetrating oil, let it sit for a few minutes, then use a properly sized wrench with steady pressure. Avoid hammering or using excessive force, which can damage the head.

Conclusion

Knowing how to remove Stihl weed eater string is a fundamental skill that keeps your trimmer performing at its best. By identifying your head type, gathering the right tools, observing safety precautions, and following the step‑by‑step procedures for bump‑feed, fixed‑line, or auto‑feed heads, you can clear old line quickly and prepare the tool for fresh line installation. Regular cleaning, inspection of springs and pawls, and adherence to best‑practice tips prevent common feeding problems and extend the life of both the head and the engine. With this comprehensive guide you are equipped to tackle line removal confidently and maintain a clean, efficient cutting edge for every landscaping task.