How to Change the Line on a Weed Eater Easily
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How to change the line on a weed eater starts with taking the spool or cutting head off the trimmer: cut a new length of the line size your manual specifies, wind it onto the spool in the direction the arrow shows, thread the ends through the eyelets, and snap the head back together. Most bump-head models follow this same sequence, though the details change from one brand to another. The steps below follow a standard bump head, and they point out the points that trip people up most often: the winding direction, the length of line, and whether the head is set up for the trimmer’s thread. A new line that does not feed usually means it went on the spool the wrong way.
Quick answer
- Check your owner’s manual for the line diameter first. The source used for this guide describes a common setup of about 10 feet of twin-strand line, or two 10-foot lengths of 0.095-inch line.
- Unscrew the bump knob, remove the inner spool and spring, and clear out any old line and debris.
- Wind the line in the direction of the arrow on the spool, leave about 6 inches of tail, and push each end into the holding slots.
- Reassemble with the spring on the shaft, feed the ends through the eyelets, and test the feed by pulling both ends free.
Before you start: check the line size and the head
The first decision is which line to buy, and the answer is in your trimmer’s manual, not in a general rule. The source used for this guide points to about 10 feet of twin-strand line or two 10-foot lengths of 0.095-inch line for a standard bump head. Some heads take a different diameter, and a line that is too thick can jam the head or put extra strain on the trimmer’s motor. If the manual lists a range of diameters, use the one that matches the slots marked on the spool.
Next, confirm that the head is the right thread for your shaft. One listing in this group describes a universal head as working with trimmers that turn counter clockwise, and it says the shaft must have a left-hand thread. The same listing warns that you must confirm the direction before you remove any nut or bolt. Getting this wrong can strip the threads, so look at the shaft and the bolt before you turn anything with force.
Finally, pick the replacement you actually need. A spool of line is the cheapest option when the head is still in good shape, while a complete head is the better choice when the housing is cracked or the spring is damaged. Several spools in this roundup are sold as direct replacements for specific cordless models, so match the model number on the listing to your trimmer before buying.
Tools and materials you need
You do not need special tools for a bump head. Keep these items on the bench before you start:
- A new length of trimmer line in the diameter your manual specifies.
- A pair of gloves to protect your hands from the spring and the line ends.
- A clean, flat work surface and a small tray for the spring and washers.
- The owner’s manual, for the line size and the winding direction.
Disconnect the power before you begin. On a gas trimmer, remove the spark plug wire. On a cordless trimmer, remove the battery. This step matters more than any other, because the head can move while you work.
Step 1: Remove the spool or cover
Turn the trimmer so the head faces up. On most bump heads, you unscrew the bump knob by turning it counter clockwise, then lift off the cover. Some heads have side tabs instead of a bump knob, and you press the tabs in to release the cover. Once the cover is off, you can see the inner spool, which holds the old line, and the spring that sits under it. Take out the spool and the spring together, and set the spring aside on the bench so it does not get lost.
Clean the housing before you load new line. Grass clippings, dirt and bits of old line can jam the spool and stop the head from feeding. Use a brush or a cloth to clear the inside of the housing and the eyelets, and check that the spring is not bent or cracked.
Step 2: Cut and wind the new line
Cut the new line to the length your manual gives. The source for this guide suggests two 10-foot pieces of 0.095-inch line for a standard bump head, or one length of twin-strand line of about 10 feet. Fold the line in half, find the midpoint, and loop it through the hole in the spool so that the two ends are even. Look at the arrow printed on the top of the spool. That arrow shows the winding direction, and it is the single most important detail in the whole job.
Wind the line tightly in the direction of the arrow. Leave 2 to 3 inches of line free at each end, then pull the line through the spool hole until it clicks into place. Wind until about 6 inches of tail are left on each side. Push each end into the holding slot that matches the line diameter. A spool that is wound against the arrow will not feed properly, and the line will spring back into the head when you try to use it.
Keep the winding even. A loose wind can tangle as it feeds out, while a tight, even wind lets the line release smoothly each time you bump the head. If the spool has two channels, make sure each side has the same number of turns so the line runs out at the same rate on both sides of the head.
Step 3: Reassemble the head
Put the spring back on the shaft first. Then feed the two line ends through the eyelets on the cutting head, pulling them through until the spool sits level with the housing. Set the spool back onto the shaft and line up its slots with the eyelets. This alignment is what lets the line come out when you bump the head.
Press the spool down to compress the spring, then screw the bump knob back in by turning it clockwise, or snap the cover into place. Hold the spool down while you tighten, because the spring will push it up if you let go too early. Check that the cover sits flat and that nothing is pinched between the cover and the spool.
Step 4: Test the feed before you start cutting
Once the head is back together, gently pull both line ends outward to make sure they are free of the holding slots. Then reconnect the spark plug or battery, start the trimmer, and bump the head briefly against the ground. If the line feeds out to the right length, you are done. If it does not feed, the most common causes are a wrong winding direction or a line that was pulled too far into the spool before the ends were seated.
If the line does not feed after one reassembly, take the head apart again and check the arrow direction first. Do not force the bump knob, because that can strip the housing.
Product notes from the pack
The products below are the line, spool and head options in this group. Each block gives only the facts the listing states, so you can match the item to your trimmer before you buy.
Toussaint universal weed eater head
This bump-feed head is made of metal and impact-resistant plastic, and the listing describes it as fitting many brands of gas trimmers and cordless string trimmers that turn counter clockwise. It names Echo, Ryobi, Ego, Dewalt, Husqvarna, Craftsman, Shindaiwa, Honda and Kobalt among the compatible brands. The listing says it is for a left-hand thread on the shaft only, and it asks you to compare the existing mounting bolt or nut on your trimmer before you order. If you are replacing a whole head rather than just the line, this is the item in the pack that addresses the thread issue directly.
Husqvarna Titanium X-Pro .095 inch trimmer line
This is a 200-foot spool of 0.095-inch line for Husqvarna trimmers. The listing says it fits the 430LS, 535LS, 535LST, 522L, 525L, 520iLX, 525LS and 525LST models. The line is round and dimpled, and the listing describes a co-extruded polymer for abrasion resistance. The item is listed as manufactured in the USA. If your trimmer is one of the Husqvarna models named in the listing, this spool is a direct fit for the line change described above.
KAKO AC14RL3A spool line for Ryobi One+ trimmers
The KAKO listing offers pre-wound spools of 11-foot, 0.065-inch nylon line that the listing says replace the AC14RL3A spool on Ryobi One+ trimmers. The bullets list compatible Ryobi models in the 18V, 24V and 40V range, and they describe an ABS spool. The listing is built around the auto-feed design, so you do not wind the line by hand. The package count shown in the listing is a bundle of 12 spools and 2 caps. If your trimmer takes the AC14RL3A spool, this is the line-only option in the pack for that model.
WETOOLPLUS WA0014 spool and cap for Worx trimmers
This WETOOLPLUS kit includes three spools and one cap, sized for Worx models WG168, WG184, WG190 and WG191. The listing says the spools are a direct replacement for the original WA0014 part and that the cap is designed to fit the same trimmer. It describes the nylon as copolymer, and it gives a cutting width of 0.08 inches. If you have one of the listed Worx trimmers and your spool has worn out, this kit covers both the spool and the cap in one order.
Foreda .080 trimmer line, 410 feet
This Foreda listing is a round nylon line of 0.080 inch for light duty trimming. The bullets say it is for grass trimming and light weeds, and that it fits most gas, electric and cordless straight-shaft trimmers. The listing gives a total length of 410 feet in a 1-pound package. If you trim mostly thin grass and want a lighter line for a standard bump head, this is the line size to check against your manual.
0.095 inch steel core string trimmer line, 164 feet
This line has a steel wire core wrapped in nylon, and the listing says that construction gives it strong break resistance against stubborn weeds and thick grass. It is 0.095 inch round and totals 164 feet. The listing says it is universal and fits most gas and electric trimmers, and it names Stihl, Ryobi, Echo and Craftsman among compatible brands. Because it is a thicker line, check that your head’s slots accept 0.095 inch before you wind it.
Common mistakes to avoid
The most frequent error is winding the line against the arrow on the spool. The line will not come out when you bump the head, and you will have to unwind it and start over. The second most common error is cutting too much or too little line. Too much can jam the housing, while too little leaves you with a line that runs out after a few minutes. Follow the length in your manual, and do not guess.
Another mistake is loosening the bump knob the wrong way on a counter clockwise thread, or forcing a head that is on a left-hand thread. Check the direction before you turn anything, and if a nut will not move, stop and look at the thread before you add force. Finally, do not run the trimmer with the head assembled loosely. A loose cover can come off during use, and that can throw debris or damage the housing.
FAQ
How often should I change the line on a weed eater?
There is no fixed schedule in the sources used for this guide. Change the line when it runs out, when it is worn down to a short stub, or when the head will not feed. Check the line each time you use the trimmer, because worn line breaks more easily and can leave you with a head that stops feeding mid-job.
Why does my new line not come out when I bump the head?
The most likely cause is that the line was wound against the arrow on the spool. Take the head apart again and check the direction. Another cause is that the line was not pulled through until it clicked into the spool, so it retracted into the head. Re-wind the line, leave about 6 inches of tail, and seat both ends in the holding slots before you reassemble.
Can I use a thicker line than the manual says?
Not without checking. A thicker line can jam the head, put extra load on the motor and damage the housing. Stick to the diameter in your manual, and if you are unsure, buy the line that matches the size printed on the spool.
Do I need to remove the head to change the line?
On most bump heads, yes. The source used for this guide describes removing the inner reel, winding the new line, and reassembling the head. Check your model’s manual before you assume any shortcut works on your head.
What line should I buy for an electric trimmer?
Choose the line size your manual lists for your model. Several listings in this roundup say they fit gas, electric and cordless straight-shaft trimmers, but a universal fit does not guarantee that the diameter will feed in your head. Match the diameter first, then the brand compatibility.
Bottom line
To change the line on a weed eater, follow the manual’s line size, wind the new line in the direction of the arrow, leave about 6 inches of tail, and test the feed before you start cutting. The winding direction and the line length are where most attempts go wrong. If the head is damaged or the thread does not match your shaft, replace the whole head rather than forcing the old one back together.
Related reading
If you are comparing trimmers before you buy, Top 10 Battery Powered Weed Eaters: 6 Real Picks Compared lists battery models with their line types. If your trimmer runs on Ryobi batteries, Best Ryobi ONE+ String Trimmers Compared looks at the spool and line options for that platform.
