Ryobi String Trimmer Line Won't Feed — Bump Head Mechanical Fix
⚡ Quick Answer
The most common reason Ryobi trimmer line won't feed is 'line welding,' where heat causes the string to fuse together on the spool, or a worn bump knob that can no longer index the internal drive lugs. To fix this, disassemble the head, clear any melted or tangled line, and inspect the bump knob for rounded plastic teeth. Ensure you are using the correct line diameter (typically .080" or .095") and that the internal compression spring is not missing or collapsed.
What do you want to do?
Most Likely Cause
Fused Trimmer Line
Excessive friction during operation causes the line to heat up and weld itself together inside the spool. Check this by attempting to pull the line manually; if it resists with a 'sticky' feel, fusion is the likely culprit.
Start here — this is the most common reason for this symptom.
Why This Problem Happens
Ryobi string trimmers utilize a centrifugal-force-based bump feed system. Inside the spool housing, the trimmer line is tightly wound around a plastic reel that is held in place by a spring-loaded tensioner. When you tap the bump knob on the ground, the internal spool physically compresses against the spring, momentarily disengaging the locking tabs or teeth that prevent the reel from rotating. This split-second release allows centrifugal force to pull the line outward through the eyelets. Failure occurs primarily when excessive friction, heat welding of the line, or mechanical binding prevents this rotational release. If the line is improperly wound or if the eyelet inserts have worn grooves, the line becomes anchored, preventing it from overcoming the static friction required to advance. Furthermore, if the spring loses its original tension or the plastic locking tabs become deformed due to heavy vibration or impact wear, the mechanical interface can no longer consistently lock and release the spool, leading to a jammed or non-feeding head.
Common Symptoms
- Bump knob feels stiff or non-responsive
- Noticeable vibration from unevenly weighted head
- Line ends recessed inside the eyelets
- Clicking sound from the head when bumping
- Trimmer line feels fused or melted within the spool
Before You Buy Parts
Quick, free inspections — check these first. Most repairs don't actually need replacement parts.
Complete Resource Guide
Complete Weed Eaters Troubleshooting & Repair Guide
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Ryobi Repair and Troubleshooting Resource Guide
Repair Overview
15–30 minutes
$0 (usually no parts needed)
First Checks — Start Here
- 1Remove the battery or spark plug wire for safety before touching the head.
- 2Check if the line is 'welded' together on the spool due to heat.
- 3Inspect the bump knob for worn-down or rounded-off locking lugs.
- 4Verify the line is wound in the correct direction (follow the arrow on the spool).
- 5Clean out all grass, dirt, and debris from inside the head housing.
- 6Ensure the internal compression spring is present and has strong tension.
- 7Check that the line is not crossed or tangled under itself on the spool.
Safety Warnings
- !Always disconnect the spark plug wire before working on the trimmer head to prevent accidental engine start.
- !Wear safety glasses to protect eyes from high-pressure debris ejected by compressed air.
- !Ensure the spring is seated perfectly in the center of the hub; an off-center spring will cause wobbling.
- !Do not attempt to 'file' the plastic eyelets, as this changes their geometry and accelerates future line wear.
- !Ensure the line ends are secured in the spool notches while loading to prevent premature unraveling.
- !Ensure all plastic tabs snap firmly into place; a loose cover can fly off during high-RPM operation.
Always disconnect the spark plug, work in a well-ventilated area, and consult a professional if unsure.
Most Likely Causes
Ranked by likelihood — tap each to see diagnosis details.
Excessive friction during operation causes the line to heat up and weld itself together inside the spool. Check this by attempting to pull the line manually; if it resists with a 'sticky' feel, fusion is the likely culprit.
The metal or plastic eyelets develop deep channels from the line cutting into them over time. These grooves trap the line, creating too much resistance for the centrifugal force to overcome during the bump action.
🔧 Step-by-Step Fix Guide
Remove and Inspect Spool
Remove the bump head cap by pressing the side release tabs. Pull the spool out and inspect the line for any signs of melting, overlapping, or irregular winding patterns.
Always disconnect the spark plug wire before working on the trimmer head to prevent accidental engine start.
Clean and Degrease Housing
Use compressed air or a soft brush to remove debris, grit, and hardened grass sap from the inside of the housing. Residual gunk is a primary cause of mechanical binding.
Wear safety glasses to protect eyes from high-pressure debris ejected by compressed air.
Check the Compression Spring
Remove the spring and measure its free length against the manufacturer's specifications. If it shows signs of rust, flattening, or permanent deformation, it must be replaced.
Ensure the spring is seated perfectly in the center of the hub; an off-center spring will cause wobbling.
Inspect Eyelet Inserts
Examine the eyelets for sharp grooves created by the line. If you can catch your fingernail in a groove, the eyelet is damaged and must be replaced to reduce friction.
Do not attempt to 'file' the plastic eyelets, as this changes their geometry and accelerates future line wear.
Rewind Line Tightly
Follow the directional arrows on the spool, ensuring you wind the line in tight, uniform layers. Do not allow the line to cross over itself, as this is the most common cause of binding.
Ensure the line ends are secured in the spool notches while loading to prevent premature unraveling.
Verify Locking Tab Engagement
Before fully reassembling, manually press the spool into the housing and listen for the distinct 'click' of the locking tabs. If the spool rotates freely without bumping, the housing or tabs are worn.
Ensure all plastic tabs snap firmly into place; a loose cover can fly off during high-RPM operation.
What To Test Next
If the basics check out, verify spark, fuel delivery, and compression in that order — the three essentials of any combustion engine.
Component Reference
Carburetor & Fuel Intake
The carburetor mixes air and fuel for combustion. A clogged jet or stuck float is the #1 cause of small engine starting and surging problems.
Spark Plug & Ignition System
The spark plug ignites the air-fuel mixture. A fouled plug, wrong gap, or failing ignition coil will prevent the engine from firing.
Oil & Lubrication System
Regular oil changes are critical. Low or dirty oil causes engine wear, overheating, and eventual seizure. Check the dipstick before every season.
Electrical & Starting System
The battery, solenoid, and starter motor work together to crank the engine. A weak battery or corroded connection is often mistaken for a fuel or spark problem.
Photos for educational reference. Actual parts may vary by make and model.
Common Mistakes to Avoid
Winding line in the wrong direction against the feed arrow
Using a heavier gauge line than the trimmer head was designed for
Applying too much force when 'bumping' on the ground
Leaving the old line on the spool while winding new line over it
If This Didn't Fix It
Still having trouble? These are the next things to check:
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Finding parts for
Ryobi string trimmer trimmer line won't feed
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Replacement Trimmer Head
If the locking teeth are deformed or the housing is permanently grooved, a full head replacement is the only way to restore the mechanical indexing required for the bump-feed mechanism to function.
Trimmer Line Spool with Pre-wound Line
Improper winding tension often causes line tangles; a factory-wound spool eliminates human error in layering and ensures the line feeds smoothly through the eyelets without binding.
Trimmer Head Spring
Spring fatigue prevents the head from resetting after a bump; replacing the compression spring restores the necessary tension to release the locking tabs so the line can advance.
Eyelet Replacement Inserts
Grooved or worn eyelets create excessive friction, which prevents line from pulling through the head even when the internal mechanism is operating correctly.
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Pro Tips from the Community
Real-world fixes from Reddit, YouTube & forums.
"Soaking your trimmer line in a bucket of water for 24 hours makes it much more pliable and significantly reduces line welding inside the head."
Reddit r/lawncare"Most Ryobi bump heads are left-hand thread. If you're struggling to get the knob off, try turning it clockwise (Righty-Loosey) to remove it."
DoItYourself.com Forum"If your line keeps welding, stop 'feathering' the trigger. Running these trimmers at half-throttle creates more heat and less cooling airflow, which melts the string."
YouTube commentsPrevent This From Coming Back
Use high-quality, manufacturer-recommended line gauge
Soak new trimmer line in a bucket of water overnight to improve flexibility
Clean the trimmer head after every use with a damp cloth
Replace the entire bump head assembly every two seasons to combat plastic fatigue
Prevent This From Happening Again
While you're fixing it, stock up on the maintenance essentials that keep your weed eaters running right.
Trimmer Line/String
Quality trimmer line breaks less and cuts cleaner.
Get on Amazon2-Cycle Oil
Fresh fuel mix prevents carb diaphragm hardening and starting issues.
Get on AmazonSpark Arrestor Screen
A clogged spark arrestor causes power loss — clean or replace it.
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Frequently Asked Questions
No. Using a line thicker than recommended by Ryobi will cause the line to bind in the eyelets and put excessive strain on the trimmer's motor, leading to overheating.
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