Symptoms
- Bumping the head doesn't release more line
- Line comes out unevenly or in short bursts
- Spool spins but line stays same length
- Line appears melted or fused inside the head
Likely causes
- CommonLine fused or melted inside the spoolHeat from cutting can melt line coils together, jamming the feed.
- CommonLine wound too tightly or crossedOverlapping wraps can jam the exit holes.
- PossibleWorn feed mechanism or springThe bump-feed mechanism wears out over time and stops advancing line.
- PossibleWrong diameter line for the trimmerLine too thick for the head can jam the feed holes.
What to do
- Turn off the trimmer and remove the battery or disconnect the spark plug before opening the head.
- Remove the spool and inspect for fused, melted, or tangled line.
- Unwind and rewind the line evenly in the direction indicated inside the spool housing, avoiding crossed wraps.
- Check the line diameter matches what the manual specifies for your trimmer.
- Inspect the feed spring and eyelets for wear or damage.
- Reassemble and test the bump-feed mechanism by hand before running the trimmer.
- If the feed mechanism itself is broken, replace the spool assembly or head.
Tools and parts
- Replacement trimmer line
- Gloves
Trimmer line spoolSearch: “string trimmer replacement spool”
Trimmer lineSearch: “trimmer line correct diameter”
When to call a pro
If the feed mechanism is worn out or broken, most repair shops can replace the trimmer head assembly quickly.
Safety
Generally low risk
Generally low risk for a careful person. Stop if anything looks different from what this guide describes.