How Do You Restring a Weedeater? (Complete Guide for All Trimmer Types)

Direct Answer: How to Restring Your Weedeater

Understanding Your Weedeater Spool Type

Weedeaters use three primary spool mechanisms, and the restringing process varies by type. Identifying your trimmer’s spool design is the first step toward successful line replacement.

Bump-Feed Spools (Most Common)

Bump-feed spools hold a single line that advances automatically when you tap the trimmer head against the ground. This is the most common residential design. The spool has two anchor points or slots where the line is secured, and you wind the line around the spool in one long spiral. Bump-feed spools are simple to restring and maintain.

Dual-Line Fixed Spools

Dual-line spools hold two separate lengths of trimmer line, each wound on opposite sides or in separate channels. The line does not advance automatically; instead, both lines are fixed at a set length and must be manually trimmed when worn. These spools are common on commercial-grade and mid-range trimmers.

Automatic-Feed Spools

Automatic-feed spools advance line as the trimmer runs, using a spring-loaded mechanism inside the spool. These require less frequent restringing but demand more care during the winding process to avoid jamming the internal mechanism.

What You’ll Need to Restring Your Weedeater

Gather these items before starting the restringing process:

• Replacement trimmer line: Buy the correct gauge (diameter) for your trimmer—check your owner’s manual or the spool packaging for specifications. Most residential trimmers use 0.065 to 0.095 inches; commercial models may use up to 0.130 inches.
• Wire cutters or trimmer line cutter: A sharp pair of scissors or dedicated line cutter ensures clean, even cuts.
• Screwdriver or wrench: Some spool caps require a Phillips or flathead screwdriver; others twist off by hand. A small adjustable wrench may be needed for bolt-on designs.
• Safety glasses: Protect your eyes when removing the old line or if the trimmer accidentally starts.
• Work gloves: Optional but helpful for grip and protection when handling the spool or old line.
• Owner’s manual: Your specific trimmer model may have unique requirements or line length recommendations.

Choosing the Right Trimmer Line

Pro tip: Buy line in bulk to save money. Trimmer line stores well and you’ll reuse it regularly. Look for co-polymer or nylon line rated for your trimmer’s RPM; thicker line cuts thicker weeds but may strain lighter trimmers.

How to Restring a Bump-Feed Weedeater (Step-by-Step)

Bump-feed spools are the easiest to restring and represent the majority of residential trimmers.

Step 1: Prepare the Trimmer

• Disconnect the spark plug wire to prevent accidental starting.
• Unplug electric trimmers from the outlet.
• Place the trimmer on a flat work surface where you have room to work.

Step 2: Remove the Spool Housing

• Most bump-feed spools have a cap that twists counterclockwise. Grip it firmly and turn it until it releases—do not force it as the threads may strip.
• Some models have two bolts holding the cap; use a screwdriver to remove them.
• Lift off the spool cap and set it aside with any springs or washers attached—note their placement for reassembly.

Step 3: Remove the Old Line

• Unwind any remaining old line from the spool by hand or with a screwdriver as a lever.
• Remove the line stub from the anchor slots (small notches on opposite sides of the spool where the line secures).
• Clean out any debris, dried grass, or old line fragments from the spool cavity.

Step 4: Measure and Cut New Line

• Check your owner’s manual for the recommended line length per fill. A typical bump-feed spool holds 15–25 feet.
• Cut a single length of trimmer line to that specification using wire cutters. Make a clean, straight cut—ragged edges may fray or jam.
• For easier winding, slightly soften stiff line by soaking it in warm water for 5 minutes.

Step 5: Thread and Wind the Line

• Locate the two anchor slots on the spool. Insert one end of the line into one slot, leaving 4–6 inches of line protruding.
• Wind the line tightly and evenly around the spool in the direction of the arrow printed on the spool face. Most spools wind counterclockwise, but always check your spool.
• Keep tension on the line as you wind to ensure it’s tight and doesn’t overlap itself.
• Wind until you reach the opposite anchor slot, then insert the remaining line end into that slot.
• Leave 4–6 inches of line protruding from each anchor slot—these become your cutting edges.

Step 6: Reinstall the Spool

• Set the wound spool back into the trimmer head, ensuring the anchor slot protruding lines feed through the two exit holes in the trimmer head.
• Replace any washers or springs in their original positions.
• Screw the cap back on clockwise until hand-tight—do not over-torque.
• If your cap has bolts, tighten them snugly with a screwdriver.

Step 7: Test the Line Feed

• Reconnect the spark plug wire.
• Start the trimmer and run it at a low idle for 10 seconds to allow the lines to settle and feed properly.
• The two line segments should extend slightly from the head.
• If lines don’t feed, turn off the trimmer, disconnect the plug, and check that the anchor slot lines are fully inserted into the exit holes.

How to Restring a Dual-Line Fixed Spool Weedeater

Dual-line spools require more precision because both lines must be wound correctly and secured independently.

Step 1–3: Prepare and Remove Old Line

Follow the same preparation and spool removal steps as the bump-feed process above.

Step 4: Identify the Line Channels

• Dual-line spools have two separate grooves or channels, one for each line. These may be on opposite sides of the spool or in concentric rings.
• Each channel typically has two anchor slots (one at each end).
• Look for directional arrows on the spool to determine winding direction for each channel.

Step 5: Thread the First Line

• Measure and cut a length of line per your manual’s specification (typically 17–25 feet for dual-line spools).
• Insert one end into an anchor slot in the first channel.
• Wind the line tightly in the channel following the arrow direction.
• Insert the opposite end into the anchor slot at the far end of the channel.

Step 6: Thread the Second Line

• Repeat the process with a second measured length of line in the opposite channel.
• Ensure both lines are wound with equal tension and that neither overlaps or touches the other.
• Both protruding line ends should extend 4–6 inches from their anchor slots.

Step 7: Reinstall and Test

• Replace the spool into the trimmer head, feeding both line ends through their respective exit holes.
• Reinstall the cap and start the trimmer at low idle to verify both lines are secure and feeding properly.

How to Restring an Automatic-Feed Weedeater

Automatic-feed spools are more delicate because the internal spring mechanism controls line advance. Improper winding can jam the spool.

Key Differences

• Automatic spools typically wind line into a tight spiral around a central post or spring.
• The line must be wound with consistent, even tension—loose sections can tangle the internal mechanism.
• Follow your manual closely; many automatic models have specific winding patterns printed on the spool.

Step-by-Step Process

• Remove the spool: Twist off the cap counterclockwise. Some automatic spools are more complex; a gentle wiggle and pull often helps.
• Check the internal spring: Look inside the spool for a spring or ratchet mechanism. Do not force or modify it.
• Remove old line: Unwind carefully to avoid tangling springs.
• Thread new line: Many automatic spools have a single anchor slot. Insert the line and wind it tightly in concentric circles, moving from the center outward or following the printed diagram. Maintain even tension throughout.
• Leave 4–6 inches protruding, then secure the end in the anchor slot.
• Reinstall the spool: Align the spool shaft with the trimmer head shaft and screw the cap on gently. If it resists, do not force—the spool may be misaligned.
• Test carefully: Start the trimmer at very low RPM and listen for grinding or jamming sounds. Stop immediately if you hear any, as the line may be caught on the internal mechanism.

Safety Considerations When Restringing

Always disconnect the spark plug wire before working on the trimmer. This prevents accidental starts that could cause injury.

• Wear safety glasses to protect your eyes from flying line fragments when removing the old spool.
• Never restring a trimmer while it’s running or hot from recent use.
• Keep your hands clear of the trimmer head opening during spool removal and installation.
• Do not wind the line too tightly—excessive tension can strain the spool bearings or snap the line during winding.
• Inspect the spool for cracks or damage before restringing. A damaged spool should be replaced, not reused.
• After restringing, test the trimmer on low grass or weeds in an open area away from bystanders, pets, or vehicles.

Troubleshooting Common Restringing Problems

The Line Won’t Feed After Restringing

Cause: Protruding line ends are not fully inserted into the exit holes, or line is wound in the wrong direction.

Solution: Disconnect the spark plug, remove the cap, and verify that both anchor slot line ends are fully pushed through the exit holes in the trimmer head. Check the arrow on the spool to confirm you wound in the correct direction. Rewind if necessary.

The Line Is Tangled or Won’t Turn

Cause: Line was wound too loosely, overlapped itself during winding, or the spool is damaged.

Solution: Remove the spool, unwind the line completely, and rewind with steady, even tension. Do not allow the line to cross over itself. If the spool is cracked or the bearing is stiff, replace the spool.

The Line Keeps Breaking

Cause: Line diameter is too thin for your trimmer model, the line is old or brittle, or the trimmer head has sharp burrs.

Solution: Check your manual for the correct line gauge and upgrade if needed. Replace very old line. Smooth any rough edges on the trimmer head with fine sandpaper.

One Line Extends More Than the Other (Dual-Line)

Cause: Unequal winding tension or anchor slot lines protruding different lengths.

Solution: Remove the cap, unwind both lines, and rewind with equal tension. Ensure both protruding ends are cut to the same length before reinstalling.

The Spool Cap Won’t Unscrew

Cause: Over-tightened cap, dirt buildup, or stuck threads.

Solution: Turn counterclockwise gently but firmly—do not use pliers as they can slip and damage the cap. If truly stuck, apply a penetrating oil (like WD-40) around the cap threads and wait 15 minutes before trying again. If bolts are stuck, soak them with penetrating oil and work them loose gradually.

Maintenance Tips to Extend Line Life

• Inspect the line before each use. Replace it if it’s frayed, brittle, or noticeably short.
• Avoid cutting into hard objects like rocks, gravel, or metal. These dull and fray the line rapidly.
• Trim at the correct height. Hold the trimmer head parallel to the ground—angling it causes uneven wear.
• Store trimmer line indoors in a cool, dry place. UV light and temperature swings degrade line over time.
• For bump-feed trimmers, tap gently when feeding new line. Hard taps can break new line or strip the spool.

Frequently Asked Questions

How often should I restring my weedeater?

This depends on use frequency and line quality. Light residential use may require restringing 2–3 times per season. Heavy use may require monthly restringing. Replace the line whenever it becomes noticeably short, frayed, or brittle. Many users maintain a schedule of restringing at the start and middle of the mowing season.

Can I use any brand of trimmer line?

Any trimmer line of the correct gauge (diameter) and material will work mechanically, but quality varies. Premium co-polymer line lasts longer and resists breakage better than cheaper alternatives. Avoid very cheap line that may be brittle or prone to tangles. For your trimmer’s compatibility, the gauge matters far more than the brand.

What if I don’t know my trimmer’s line size?

Check the owner’s manual—the gauge is always listed there. If you’ve lost the manual, check the spool itself; many spools have the line gauge stamped or printed on them. You can also contact the trimmer’s manufacturer with your model number. As a last resort, measure the old line with a digital caliper or ruler and match the diameter at a hardware store or online retailer.

Is it worth restringing an old trimmer, or should I buy a new one?

Restringing costs $5–15 and takes 10–15 minutes, so it is almost always worthwhile unless the trimmer itself is damaged. Only consider replacing the trimmer if the spool is cracked, the engine won’t start, or the shaft is bent. A properly maintained trimmer can last many years with routine line replacements and seasonal maintenance.

Final Thoughts

Restringing a weedeater is a simple skill that pays dividends in cost savings and trimmer reliability. Whether your trimmer uses a bump-feed, dual-line, or automatic-feed spool, the core process is the same: access the spool, remove old line, measure and cut new line, wind it tightly in the correct direction, and reinstall. Always consult your owner’s manual for model-specific details, and never skip the safety step of disconnecting the spark plug before work. With practice, you’ll complete a full restring in under 15 minutes and keep your trimmer ready for the season.