You’re halfway through trimming a customer’s lawn when the line stops feeding. You bump the head on the ground. Nothing. The spool is empty. Knowing how to string a weed eater before that happens keeps your crew moving without a 20-minute delay mid-job. This guide covers every head type you’ll run into, the step-by-step restringing process for bump-feed and two-hole spools, pre-wound spool replacements, and how to pick the right trimmer line for the job.
Quick Answer: The key to stringing a weed eater is knowing which type of trimmer head you have first. Most trimmers use a bump-feed spool: remove the cap, pull out the spool, clear old line, thread 9 to 20 feet of new trimmer line through the anchor slot, wind neatly in the direction of the arrows, feed the ends through the eyelets, and snap the cap back on. Use the line gauge your trimmer’s manual specifies, the wrong size causes jams and motor strain.
What Type of Weed Eater Head Do You Have?
Before restringing anything, identify your trimmer head. The process is different for each type, and using the wrong approach wastes time and line.
| Head Type | How It Works | Common Models |
|---|---|---|
| Bump-feed | Bump the head on the ground to release more line | Husqvarna, Echo, Craftsman, Ryobi gas trimmers |
| Auto-feed | Line advances automatically during operation | Ryobi, Black+Decker battery trimmers |
| Fixed-line / Fixed-head | Pre-cut line inserts directly into slots, no spool | Commercial brush cutters |
| Pre-wound spool | Drop-in replacement spool, no winding required | Stihl Speed-Feed 400, Oregon EZ-Feed heads |
Bump-feed heads are the most common type on both residential and professional gas trimmers. If you run a Stihl with a Speed-Feed or AutoCut head, skip ahead to the pre-wound spool section.
For a full breakdown of how each trimmer type is used on the job, what is weed eating: how to use a weed eater the right way covers the tools and techniques in detail.
How to String a Bump-Feed Weed Eater (Step-by-Step)
This is the standard method for how to restring a weed eater across most gas and battery-powered trimmers, including Husqvarna, Echo, Ryobi, and Craftsman. You’ll need replacement trimmer line in the correct gauge for your machine, gloves, and scissors or a line cutter.
Step 1: Power down the trimmer. Turn off the engine or disconnect the battery. Never work on the trimmer head while the motor is live.
Step 2: Remove the spool cap. Press the tabs on both sides of the cap and twist counterclockwise, or push-and-pull depending on your model. The cap is typically color-coded orange, red, or black.
Step 3: Lift out the spool. Before removing the spool completely, note the winding-direction arrows printed on its face. Getting this wrong is the single most common reason line jams after restringing.
Step 4: Clear all old line. Pull off any remaining trimmer line from the spool. Old line left on the spool tangles with new line during winding and causes misfeeds.
Step 5: Cut your replacement line. For a single-line spool, cut 9 to 12 feet. For a dual-line spool, cut a single 20-foot length. Cut the end at a slight angle so it points, which makes threading through small holes and anchor slots much easier.
Step 6: Insert the line into the anchor slot. Find the small hole or notch at the center hub of the spool. Insert one end (single-line) or the midpoint fold (dual-line) into this anchor. It should click or seat firmly.
Step 7: Wind neatly in the direction of the arrows. Wind each layer tightly and evenly, keeping the line flat without overlaps or crossed sections. Crossed winding is the second most common cause of feed jams. Fill the spool to about 1/4 inch below the rim, leaving enough room for the cap to seat.
Step 8: Feed the line ends through the eyelets. Leave 6 to 8 inches of free line out of the spool. Thread each end through the guide holes (eyelets) on the trimmer head housing, then clip them into the notches on the spool rim to keep tension while you reassemble.
Step 9: Seat the spool and replace the cap. Press the spool down into the housing, confirm the line ends are fully through the eyelets, and press or twist the cap back on until it clicks. Give each line end a firm tug to confirm it’s seated and feeding freely.
Step 10: Test the feed before starting. With the trimmer still off, bump the head on the ground once. Both lines should advance slightly. If nothing moves, the spool is likely seated incorrectly or the winding direction is reversed.
How to String a Weed Eater with Two Holes (Dual-Line Method)
If your trimmer head has two eyelet holes instead of one, you’re working with a dual-line setup. This is standard on many commercial-grade Husqvarna and Echo models, and it’s the setup behind the common question “how to wind a two string weed eater.”
The process for how to put string in a weed eater with two holes follows the same steps as bump-feed restringing, with two important differences.
First, thread line through both eyelets. Cut a single 20-foot length of replacement line. Find the exact midpoint and fold it there. Insert the fold into the center anchor slot so each side has equal length. Wind both sides simultaneously in the same direction, following the printed arrows, without letting the two layers cross each other. Treat each side as its own track.
Second, when reassembling, each end of the line feeds through its own designated eyelet. If the head has numbered holes marked 1 and 2, match each line to the correct hole. Mismatching them causes one line to wrap around the other inside the head, which locks up the feed.
Lawn care pros who run dual-line heads regularly learn quickly: if the line keeps jamming after restringing, the winding direction is almost always to blame. Hold the spool up so you can clearly read the arrows before you start winding, and don’t rush this step.
How to Replace a Pre-Wound Spool (Stihl Speed-Feed and Drop-In Heads)
The pre-wound spool approach is the fastest restringing method available, and it’s especially useful in the field. There’s no winding, no measuring, and no threading through center slots.
Step 1: Power off and remove the head cap. On a Stihl Speed-Feed 400 head, the cap is a large, center-mounted knob. Turn it counterclockwise by hand to remove.
Step 2: Lift out the old spool. Pull it straight out and discard it. The pre-wound spool is a single-use replacement.
Step 3: Drop in the new spool. Align the line ends with the guide holes on the housing and press the spool down until it seats firmly.
Step 4: Thread the line ends through the eyelets. Pull each end through its respective guide hole until there’s 6 inches of free line on each side.
Step 5: Replace the cap and hand-tighten. Do not use tools. Over-tightening cracks the cap on most Speed-Feed and Oregon-style heads.
Pre-wound spools cost more per fill than bulk trimmer line, but the time savings matter during a full day of trimming. Both Stihl and Oregon produce pre-wound drop-in options for their respective heads. The string weed eater guide covers the broader range of trimmer head accessories and replacement line options that work with professional-grade trimmers.
Choosing the Right Trimmer Line Gauge
Not all trimmer line is interchangeable. Running the wrong diameter can overload the motor, cause constant breakage, or fail to cut through dense vegetation.
| Line Diameter | Best For | Typical Equipment |
|---|---|---|
| .065″ | Light residential trimming, thin grass | Corded electric trimmers |
| .080″ | Standard residential use | Most gas and battery trimmers |
| .095″ | Medium-duty, thicker weeds | Mid-grade gas trimmers |
| .105″ | Heavy residential, light brush | Professional gas trimmers (Echo, Stihl) |
| .130″ | Commercial use, heavy brush clearing | High-output commercial trimmers (Husqvarna) |
The correct gauge is almost always printed on the label on the spool housing. Check there first before buying replacement line. Using line that’s too thick stalls the motor over time. Line that’s too thin snaps on every pass through dense vegetation.
Round vs. twisted vs. serrated line: Round line is the standard for most residential and commercial trimming jobs. Twisted and serrated profiles cut more aggressively and hold up better in heavy brush, but they cost more and aren’t necessary for routine edging and cleanup work. Oregon’s trimmer line guide breaks down how line shape and diameter interact for different vegetation types.
For commercial crews managing multiple trimmers, Turf Magazine covers outdoor power equipment maintenance and line selection in depth as part of their professional equipment coverage.
The bottom line on line selection: match the gauge to your manual first, then choose the profile based on what you’re cutting.
Frequently Asked Questions About Weed Eater String
Can weed eaters use any type of string?
No. Weed eaters require purpose-made monofilament trimmer line. Rope, wire, and fishing line will damage the trimmer head or create a safety hazard during operation. The line must match the diameter specified in your trimmer’s manual. Major brands including Echo, Stihl, and Husqvarna all produce line engineered for their trimmers, though standard gauges from any reputable manufacturer are generally cross-compatible. For professional crews, OSHA’s outdoor power equipment guidelines outline the safety standards that apply to string trimmer operation on job sites.
Should you soak trimmer line in water before stringing?
Soaking trimmer line in warm water for 24 hours before use reduces breakage, particularly in hot and dry conditions. Nylon trimmer line absorbs moisture and becomes more flexible, which helps it handle the impact of cutting without snapping. It’s not mandatory, but crews working in the South and Southwest during summer often build this into their prep routine. Submerge the full coil overnight and allow it to dry slightly before threading.
How long should trimmer line be for a two-hole weed eater?
For a standard dual-line bump-feed spool, cut a single piece of line about 20 feet long. Thread the midpoint through the center anchor slot so you have roughly 10 feet winding on each side. If you’re working with a smaller battery trimmer, check the label on the spool housing for the maximum recommended fill length. Overfilling a small spool causes the line to bind against the cap during operation.
How do you know when to restring a weed eater?
Restring when the line is too short to extend from the head (under 2 to 3 inches per side), when the trimmer loses cutting efficiency, or when bumping the head produces no new line. On a busy trimming day, a full spool can run empty after several properties depending on vegetation density. Most lawn care professionals keep pre-cut lengths of replacement line or a spare spool in their trailer to avoid stopping mid-job. For technique adjustments that reduce unnecessary line breakage, how to weed whack your lawn covers proper cutting angle and head distance to extend spool life on each fill.
Restring Fast, Trim Clean
Knowing how to string a weed eater properly turns a potential mid-job delay into a 5-minute swap. Identify your head type first, match the line gauge to your trimmer’s specs, wind neatly in the direction of the arrows, and confirm the feed works before you start cutting. That’s the whole process.
If your crew handles high-volume trimming and equipment prep is eating into job time, LawnGuru connects property owners with vetted lawn care professionals who arrive ready to work. Get a quote in minutes and skip the equipment hassle.
