How to Replace Weed Eater String Step by Step
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How to Replace Weed Eater String Step by Step
To replace weed eater string, disconnect the trimmer from its power source, open the head, remove the old spool, load fresh line, and reassemble the head. Most trimmer heads follow this same pattern, although the exact clips and caps differ by brand and model. This guide walks through the steps in order, notes what to check first, and lists a replacement spool that the listing describes for Black and Decker trimmers.
Quick answer
- Disconnect the trimmer from power before you touch the head. For a battery model, remove the battery.
- Open the head by pressing the clips and lifting off the top cap, then take out the old spool.
- Pull about 3 to 4 inches of new line through the hole in the spool, then reassemble the cap.
- Use a replacement spool that matches your trimmer. The KAKO AF100 listing is sold for Black and Decker AF100 spools.
What you need before you start
Gather a replacement spool or a length of trimmer line, and a clean, flat work surface. Check the trimmer’s manual for the line diameter it takes. The KAKO AF100 listing gives a line diameter of 0.065 inch, but confirm the size your trimmer requires before you buy. Keep the old spool nearby so you can compare the fit and the winding direction.
A replacement spool is often the simplest route. The KAKO listing says each spool comes pre-wound with 30 feet of 0.065-inch nylon line, so there is no winding to do. For a bare-line refill, the listing does not give a winding method, so follow your manual.
Step 1: Disconnect power
Before you touch the cutting head, disconnect the trimmer from its power source. On a cordless trimmer, press down on the sides of the battery and remove it. Do this before you open the head, even if the trimmer is switched off, because the head can move while you work. This is the single most important safety step in the process.
Step 2: Open the head
Press the clips on the trimmer head with one hand and lift off the top cap with the other. On many heads the cap is held by clips rather than screws. If you find screws instead, remove them with the correct screwdriver and keep them in a safe place. The cap usually lifts straight up once the clips release. Do not force it, because a forced cap can bend the spool hub.
Step 3: Remove the old spool
Lift the old spool out of the housing. Note how it sits, which side faces up, and whether any spring or spool cap comes loose with it. The KAKO AF100 listing includes three spool caps and three springs with its spool pack, so you can compare the parts and reuse any that fit your trimmer. Clean any grass or debris from the housing before you load the new spool.
Step 4: Load the new line
Pull about 3 to 4 inches of new string out of the spool and feed it through the hole in the head. This is the step where most people go wrong, because the line can slip back into the housing if the length is too short. The Ryobi trimmer head guide we opened uses this same measure, but a different head may need a different length. If your head takes two lines, feed the second line through its own hole and make sure both ends are the same length.
If you buy a pre-wound replacement spool, follow the spool’s own instructions for threading. The KAKO listing describes the spool as having an elliptical shape designed to reduce drag, and says it is pre-wound. It does not describe the threading steps in detail, so compare the spool with your old one before you feed the line.
Step 5: Reassemble the head
Put the spool back into the housing with the same orientation as the old one. Replace the cap and press it down until the clips snap into place. Make sure the cap sits flat, with no gaps around the edge, before you reinstall the battery or plug the trimmer back in.
Step 6: Feed more line if needed
Many heads let you feed more line by pressing a button and pulling the line out. The Ryobi guide we opened describes pressing a grey button and pulling more string out when more is needed. Your head may use a different button or a tap on the ground, so check your manual. Pull out only enough line to reach the cutting length you need.
Step 7: Reinstall power and test
Reinsert the battery, or reconnect the trimmer to power. Run the trimmer briefly to check that the line feeds out and that the head turns freely. Keep the trimmer away from people and pets during the test, and point the head away from your body.
Common mistakes to avoid
The most frequent problem is loading the new line too short. The line then pulls out of the head during use. The second problem is putting the cap back on with the clips out of place. The third is reloading a spool with a line diameter the trimmer does not accept. Check the diameter in your manual or on the spool label before you load. The KAKO listing gives 0.065 inch for its AF100 spool, and it says the spool is made for Black and Decker AF100 models along with several other Black and Decker trimmer models.
Replacement spool: KAKO AF100 for Black and Decker trimmers
The KAKO AF100 spool is listed as a replacement for Black and Decker weed eater spools. The listing says it is compatible with AF-100, AF-100-3ZP and AF-100-BKP spools, and also names GH600, GH610, GH900, LST136, LST140 and LST201 trimmers. Each spool is pre-wound with 30 feet of 0.065-inch nylon line on an ABS hub. The listing says the spool has an elliptical shape designed to reduce drag, and it claims that increases cutting efficiency. That is a claim from the listing, and this guide does not test it.
Before you buy, confirm that your trimmer’s model appears in the listing and that your old spool matches the AF100 design. If your trimmer is not on that list, check the manual for the correct spool.
When a new spool is not the answer
If the head is cracked, the clips no longer hold, or the housing is damaged, replacing the spool will not fix the trimmer. In that case, look at a new head for your model. For help choosing a trimmer, see our guide to the best Ryobi ONE+ string trimmers.
FAQ
Do I need to disconnect the trimmer before replacing the string?
Yes. Disconnect power before you open the head. On a cordless trimmer, remove the battery. This keeps the head from moving while you work.
How much string should I pull out?
The Ryobi trimmer head guide we opened says to pull about 3 to 4 inches of string from the new spool and feed it through the hole. Check your manual if your head uses a different method.
What line diameter do I need?
Use the diameter your manual specifies. The KAKO AF100 spool is listed at 0.065 inch, and a replacement spool should match the size printed on your old spool or in the manual.
Is the KAKO spool compatible with every Black and Decker trimmer?
No. The listing names the AF-100, AF-100-3ZP and AF-100-BKP spools, and trimmer models GH600, GH610, GH900, LST136, LST140 and LST201. Check your model against that list before you buy.
How do I know which way to wind the line?
A pre-wound spool, such as the KAKO AF100, avoids the need to wind line. For a bare-line refill, the guide we opened does not cover winding direction, so use your manual or the head’s markings.
Why does my new line keep slipping out?
The usual cause is loading the line too short or reassembling the cap with the clips out of place. Reopen the head, check both, and try again.
Bottom line
To replace weed eater string, disconnect power, open the head, remove the old spool, load about 3 to 4 inches of new line, and reassemble the cap. A pre-wound replacement spool saves the winding step. Check your trimmer model against the listing before you buy, and use the line diameter your manual specifies.
Related reading: BLACK+DECKER Weed Wacker with Auto Feed, 14-Inch 2 in 1 String Trimmer Lawn Review and How to Cut Tall Weeds With a String Trimmer.
Sources
Product mentioned in this guide
KAKO AF100 Spool for Black Decker Weed Eater String, 0.065 in 30 ft Autofeed Spool
A pre-wound replacement spool with 30 feet of 0.065-inch nylon line, listed for Black and Decker AF100 spools and several other Black and Decker trimmer models. The package includes 16 spools, 3 spool caps and 3 springs.
