How to String a Weed Eater | Spool Loading Made Simple

Every weed eater eventually runs out of line, and knowing how to restring it properly saves both time and money. The exact steps vary by head type, but the core process stays the same across most models. Before touching anything, power off the trimmer, unplug it, or remove the battery, and set it on a flat surface.

What Line Size Does Your Trimmer Need?

Matching the correct line diameter matters more than any other step. Check the trimmer head itself or the owner’s manual for the spec.

The head will usually have this number stamped directly on it. Using the wrong size is the fastest way to ruin a spool and waste an afternoon.

Overfilling leaves no room for the line to release, so err on the shorter side.

Steps To Restring A Standard Bump-Feed Head

Standard bump-feed heads are the most common and the easiest to master once you understand the sequence. Here’s the order that works for nearly every model:

1. Press the two release tabs on the head’s side and pull the cap off. The spool sits underneath.
2. Remove the old line and clear any dirt or grass clippings packed into the head — debris here causes most feed failures.
3. Insert the new line into the anchor hole on the spool’s inner rim.
4. Wind the line in the direction of the arrow printed on the spool or the head. This is the single most common mistake; winding backward guarantees a jam.
5. Leave 4 to 6 inches of line protruding, then thread the ends through the eyelets on the head’s outer casing.
6. Reassemble the cap until it clicks, then gently tug each line end to confirm it feeds.

When it works, the line releases cleanly when you tap the head on the ground while the trimmer runs. If nothing feeds, the spool is either overwound or wound backward.

Quick-Load And Dual-String Heads

Quick-load heads skip the winding entirely, which is why many newer trimmers use them. Instead of spooling line by hand, you thread one end through the head’s opening and push it until it catches, then feed the rest through the exit hole. Pull firmly to seat it, and the head does the winding internally as you pull. There’s no anchor hole to find and no arrow to follow.

Dual-string heads hold two separate lines, one per side, divided by a center wall. Load each side independently by following the standard winding steps for each chamber. The divider exists to keep the strands from tangling, so never wind one continuous piece across both sides.

These are the fastest to change but cost more per refill. Whichever type your trimmer uses, the head’s markings will tell you the direction and size.

For heavy-duty mowing sessions, the right line makes a noticeable difference. If you’re buying in bulk or upgrading from basic round line, our roundup of the best commercial weed eater string covers the options that hold up to thick brush and extended use.

After restringing, run the trimmer for a few seconds at low throttle to let the line seat properly. The head should feed fresh line with a firm tap, and the cutting width should match the guard’s size. If the line whips unevenly, one side is wound tighter than the other — unwind and redo that side.