How Do You String a Stihl Weed Eater? FixCut vs AutoCut

Introduction

If you have ever stood in front of a tangled spool of trimmer line and wondered How Do You String a Stihl Weed Eater? you are not alone. Properly loading the cutting head is the single most important maintenance task for keeping your Stihl trimmer running smoothly, delivering clean cuts, and preventing premature wear on the engine. This guide walks you through every detail — from understanding the two most common head designs, FixCut and AutoCut, to a step‑by‑step loading procedure, common pitfalls, maintenance tips, and answers to the questions owners ask most often.

Table of Contents

• Introduction
• Understanding Stihl Weed Eater Heads
• Types of Cutting Heads: FixCut vs AutoCut
• Comparison Table: FixCut vs AutoCut
• Tools and Materials You’ll Need
• Safety Precautions Before You Begin
• Step‑by‑Step: Stringing a FixCut Head
• Step‑by‑Step: Stringing an AutoCut Head
• Common Mistakes and How to Avoid Them
• Maintenance Tips for Long‑Lasting Line
• Troubleshooting Line Feed Issues
• Frequently Asked Questions
• Conclusion

Understanding Stihl Weed Eater Heads

Stihl trimmers ship with either a fixed‑line head (FixCut) or a semi‑automatic feed head (AutoCut). Both designs serve the same purpose — delivering a fresh length of nylon line to the cutting zone — but they operate on fundamentally different mechanics. Knowing which head you have is the first step in answering How Do You String a Stihl Weed Eater? correctly.

The FixCut head holds a pre‑measured length of line that you manually wind onto a spool. When the line wears down, you stop the engine, remove the spool, and rewind a new segment. The AutoCut head, by contrast, uses a spring‑loaded bump‑feed mechanism. A quick tap of the head on the ground advances the line automatically, so you rarely need to open the head during a job.

Both heads are compatible with the same diameter line (typically 0.080 in or 0.095 in for most residential models), but the loading technique differs enough that mixing up the procedures can cause jams, uneven feed, or even damage to the head housing.

Types of Cutting Heads: FixCut vs AutoCut

Choosing between FixCut and AutoCut often comes down to personal preference, the type of vegetation you tackle, and how much downtime you’re willing to accept for line changes. Below is a quick overview of each system’s characteristics.

FixCut – Manual Fixed‑Line Head

The FixCut head is the classic “spool‑and‑wind” design. You purchase a spool of bulk line, cut a length (usually 10–12 ft), thread it through the eyelets, and wind it evenly onto the spool. Because you control the exact length, you can tailor the line to the job — shorter for tight edging, longer for heavy brush. The downside is that every time the line breaks or wears out, you must stop, open the head, and rewind.

AutoCut – Bump‑Feed Semi‑Automatic Head

AutoCut heads contain a small spool pre‑loaded with line and a spring‑loaded feed pawl. When the line shortens, you simply bump the head against the ground while the engine is running; the centrifugal force releases a few inches of fresh line. This system shines on large properties where you want uninterrupted cutting. However, the internal spring and pawl can wear, and the head must be opened periodically for cleaning or to replace the internal spool.

Comparison Table: FixCut vs AutoCut

Tools and Materials You’ll Need

Before you start, gather the following items. Having everything at hand prevents interruptions and ensures a clean, safe loading process.

• Stihl trimmer (engine off, spark plug disconnected)
• Correct diameter trimmer line (check owner’s manual — usually 0.080 in or 0.095 in)
• FixCut spool or AutoCut replacement spool (if replacing the entire spool)
• Scissors or a sharp utility knife for cutting line
• Gloves (cut‑resistant preferred)
• Safety glasses
• Clean rag or shop towel
• Small flat‑head screwdriver (for AutoCut head cover screws, if applicable)

Safety Precautions Before You Begin

Working on a power tool always carries risk. Follow these precautions every time you service the cutting head.

1. Turn the engine off and allow it to cool completely.
2. Disconnect the spark plug wire to eliminate any chance of accidental start.
3. Wear safety glasses to protect your eyes from snapped line fragments.
4. Use cut‑resistant gloves; the line can snap with surprising force.
5. Work on a stable, flat surface — preferably a workbench or a clean patch of grass.
6. Keep children and pets at a safe distance.

Step‑by‑Step: Stringing a FixCut Head

The FixCut procedure is straightforward but requires attention to winding direction and tension. Follow these steps exactly.

1. Remove the Head Cover

Locate the retaining knob or screw on the side of the head. Turn it counter‑clockwise until the cover lifts off. Set the cover aside on a clean rag.

2. Remove the Old Spool (if present)

Pull the spent spool straight out. If the line is still partially wound, unwind it completely and discard.

3. Cut the New Line

Measure a length of 10–12 ft (3–3.6 m) from the bulk spool. Cut cleanly with scissors or a utility knife. A clean cut prevents fraying that can jam the eyelets. (See Also:How To Open Stihl Weed Eater Head)

4. Thread the Line Through the Eyelets

Insert one end of the line into the lower eyelet (the one nearest the spool hub). Pull it through until the line emerges from the opposite eyelet. Ensure the line runs straight, not twisted.

5. Wind the Line Onto the Spool

Hold the spool with the hub facing you. Begin winding the line in the direction indicated by the arrow on the spool (usually clockwise). Keep each turn tight and side‑by‑side; avoid overlapping or gaps. Continue until the spool is full but not bulging.

6. Secure the Line Ends

Most FixCut spools have a small notch or slot near the hub. Slip the free end of the line into this notch to lock it in place. Repeat for the other side if the spool is dual‑feed.

7. Reinstall the Spool

Slide the wound spool back into the head housing, aligning the hub with the drive shaft. Press firmly until it seats fully.

8. Replace the Head Cover

Align the cover tabs, then turn the retaining knob clockwise until snug. Do not overtighten — the cover should spin freely when the engine runs.

9. Test the Feed

Reconnect the spark plug wire, start the engine, and let the head spin at low RPM. The line should extend evenly from both eyelets. If one side feeds longer, stop and re‑wind that side.

Step‑by‑Step: Stringing an AutoCut Head

AutoCut heads are designed for quick spool swaps. The procedure below covers both a full spool replacement and a simple line refill on the existing spool.

1. Remove the Head Cover

Most AutoCut heads use a single screw or a quick‑release latch. Loosen the screw with a flat‑head screwdriver or press the latch and lift the cover off.

2. Remove the Old Spool

Grasp the spool hub and pull straight out. If the spool is stuck, gently wiggle it side‑to‑side — never pry with a metal tool, as this can damage the housing.

3. Inspect the Spring and Pawl

Before installing a new spool, check the feed spring and pawl for wear, corrosion, or debris. Clean with a dry rag; replace the spring kit if the pawl does not snap back crisply.

4. Install the New Spool (or Refill Existing)

If you have a replacement spool, simply slide it into the housing, aligning the drive splines. For a refill, unwind the old line completely, then follow the same winding steps as the FixCut (measure 10–12 ft, thread eyelets, wind in the direction of the arrow). Ensure the line sits in the spool’s guide channels.

5. Re‑engage the Feed Mechanism

After the spool is seated, verify that the bump‑feed pawl contacts the spool’s feed cam. Rotate the spool by hand; you should feel a slight click each revolution.

6. Replace the Head Cover

Snap the cover back on or tighten the retaining screw. Confirm the cover sits flush and does not wobble. (See Also:How To Remove Head From Craftsman Weed Eater)

7. Test the Bump‑Feed

Reconnect the spark plug, start the engine, and let it idle. Lightly tap the head on the ground while the engine runs. Fresh line should extend 2–3 in per tap. If nothing feeds, re‑check the pawl engagement.

Common Mistakes and How to Avoid Them

Even experienced users slip up. Here are the most frequent errors and the fixes that keep your trimmer running cleanly.

• Winding the line in the wrong direction. Always follow the arrow on the spool. Reverse winding causes the line to bind and snap.
• Over‑filling the spool. A bulging spool prevents the cover from seating and can crack the housing. Leave a small gap (about 1/8 in) at the outer edge.
• Using the wrong line diameter. Thicker line than specified overloads the motor; thinner line wears out instantly. Check the manual.
• Neglecting to clean the head before reloading. Grass clippings and dirt accumulate in the eyelets and feed mechanism, causing uneven feed. A quick brush‑out saves hours of frustration.
• Forgetting to disconnect the spark plug. An accidental start while your fingers are near the spinning head can cause serious injury.
• Skipping the test run. Always run the trimmer at low speed after loading. It reveals mis‑wound line before you’re deep in the yard.

Maintenance Tips for Long‑Lasting Line

Proper line care extends the interval between reloads and protects the head’s internal components.

• Store line in a cool, dry place. UV exposure and moisture make nylon brittle.
• Cut line at a 45° angle. A tapered end feeds smoother through the eyelets.
• Rotate the spool periodically. On FixCut heads, flip the spool end‑for‑end every few loads to even out wear.
• Lubricate the AutoCut spring lightly. A drop of lightweight machine oil on the spring coil reduces friction and prevents rust.
• Inspect the drive shaft splines. Worn splines cause the spool to slip, leading to uneven line feed.
• Replace the entire head every 2–3 years. Even with perfect line management, the housing and feed mechanism fatigue over time.

Troubleshooting Line Feed Issues

When the line refuses to advance or feeds unevenly, run through this quick diagnostic checklist.

1. Line not feeding at all. Verify the spool is seated fully and the cover is locked. On AutoCut, ensure the pawl engages the cam.
2. Only one side feeds. Check for a twisted line or a blocked eyelet. Re‑thread both sides symmetrically.
3. Line snaps immediately. The line may be too thin, old, or the spool over‑wound. Replace with fresh, correct‑diameter line and reduce winding tension.
4. Excessive line feed (line runs out fast). On AutoCut, the spring may be too strong or the pawl worn. Replace the spring kit.
5. Head vibrates excessively. Unbalanced spool winding or a cracked housing. Re‑wind evenly or replace the head.

Frequently Asked Questions

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

Yes, as long as the diameter matches the specification in your owner’s manual (typically 0.080 in or 0.095 in). Premium lines with reinforced cores last longer but cost more.

How often should I replace the line on a FixCut head?

Under normal residential use, expect to rewind every 10–15 minutes of cutting. Heavy brush or wet grass shortens that interval.

Is it okay to bump‑feed a FixCut head?

No. FixCut heads lack a bump‑feed mechanism. Attempting to bump them can damage the spool hub and the drive shaft.

What does the arrow on the spool mean?

It indicates the winding direction. Wind the line in the direction of the arrow; winding opposite causes the line to unwind during operation. (See Also:How To Take Off Dewalt Weed Eater Head)

Can I convert a FixCut head to AutoCut?

Stihl offers conversion kits for some models, but the process involves replacing the entire head assembly. Consult your dealer for compatibility.

Why does my AutoCut head keep jamming?

Common causes: debris in the feed channel, a worn pawl, or an over‑filled spool. Clean the head, inspect the pawl, and ensure the spool isn’t bulging.

How do I know when the AutoCut spring needs replacement?

If the bump‑feed requires multiple hard taps to advance line, or the line feeds unevenly, the spring has likely lost tension.

What safety gear is mandatory when reloading line?

At minimum, safety glasses and cut‑resistant gloves. Hearing protection is recommended if the engine is running during a test feed.

Conclusion

Mastering the art of loading your Stihl trimmer head transforms a frustrating chore into a quick, confidence‑boosting routine. Whether you own a FixCut or an AutoCut system, the core principles remain the same: use the correct line diameter, wind or install the line in the proper direction, keep the head clean, and always test the feed before you tackle the yard. By following the step‑by‑step procedures outlined above, you’ll answer the question How Do You String a Stihl Weed Eater? with ease every season, keep your equipment running at peak performance, and enjoy cleaner edges with less downtime. Happy trimming!