The basic steps to replace Ryobi weed eater string

Replacing the string on a Ryobi weed eater takes about five minutes once you know where the parts are. You'll unscrew the head cap, remove the old spool, wind new string onto it in the correct direction, and snap everything back together. The whole job requires no tools beyond what comes with the machine—usually just your hands.

The exact steps depend on whether you have a manual-feed or automatic-feed model, but both use the same basic principle: the string winds around a spool inside a plastic head, and when you turn the head, the string unwinds and cuts grass. When the string wears down, you rewind it or swap in a new spool.

Key Takeaways

  • Stop the engine and let it cool before you touch the string head, since the spool can still spin from momentum.
  • Most Ryobi weed eaters use 0.080-inch diameter string, but check your manual or the head itself to confirm the size your model needs.
  • Wind the string clockwise around the spool in the direction marked on the head—winding it backward will cause it to tangle when you use the machine.
  • Leave about 6 inches of string sticking out on each side of the spool so the trimmer head can feed it correctly.
  • If your model has a pre-wound spool, you can buy a replacement spool instead of winding string yourself.

What you'll need before you start

You need replacement string that matches your Ryobi model's diameter. Most Ryobi weed eaters use 0.080-inch string, but some older or specialty models use 0.065-inch or 0.095-inch. Check the label on your trimmer head or look up your model number in the manual to be certain. Buying the wrong size won't fit the spool or feed correctly.

You'll also want a pair of scissors or a utility knife to cut the string to length. Some people use the cutting notch built into the trimmer head itself, but scissors give you more control. Have a clean, flat surface to work on—a table or workbench is ideal so you don't lose small parts in the grass.

If your Ryobi model uses a pre-wound spool (some newer models do), you can skip the winding step entirely and just buy a replacement spool. Check whether your head has a removable spool or if the string winds directly onto a fixed spool. The manual will tell you, or you can look at the head itself—if you see a separate plastic spool that twists out, you have a removable one.

How to remove the old string and spool

Turn off the engine and let it sit for at least five minutes. The spool can still spin from momentum even after you stop the machine, and touching it while it's moving can catch your fingers. Once it's cool and still, locate the trimmer head at the bottom of the shaft.

Most Ryobi heads have a cap that screws counterclockwise. Hold the head steady with one hand and turn the cap left with the other. It should come off without much force—if it's stuck, try wrapping a cloth around it for better grip, but don't use pliers or a wrench, which can crack the plastic. Once the cap is off, pull out the spool. If it's a removable spool, it will slide straight out. If the string is wound on a fixed spool, you'll just be removing the cap to access the winding area.

Pull off any remaining old string. If there's a lot of tangled string still on the spool, you can soak the head in warm water for a few minutes to soften the dried grass and debris, then pick it clean with your fingers or a soft brush.

Winding new string onto the spool

Look at the spool and find the arrow or directional marking that shows which way to wind. This is critical—if you wind backward, the string will tangle when you use the trimmer. The arrow almost always points clockwise when you're looking down at the spool from above.

Cut a length of string about 20 feet long to start. Insert one end into the small notch or hole at the edge of the spool (your manual will show you exactly where). Wind the string tightly and evenly around the spool in the direction the arrow indicates. Keep tension on the string as you wind so it doesn't bunch up or overlap itself. Wind until you have about 6 inches of string left sticking out from the spool.

Once you've wound one direction, you'll typically wind the other direction on the other side of the spool to balance the load. Some Ryobi models have a divider in the middle of the spool that separates the two sides. Wind the second side the same way—clockwise, tight, and leaving 6 inches sticking out. If your spool has only one winding area, you're done winding.

Cut the string cleanly with scissors. Ragged edges can fray and tangle, so take a moment to make a straight cut.

Reinstalling the spool and cap

Slide the spool back into the head, making sure the string ends are positioned in the small notches or slots on the sides of the head. These slots guide the string as it feeds out when you use the trimmer. If the string isn't seated in the slots, it won't feed correctly and may jam.

Screw the cap back on by turning it clockwise. Tighten it firmly but not so hard that you crack the plastic. You should feel a slight resistance when it's snug enough. If you over-tighten and crack the cap, the head will leak oil and the spool won't stay in place.

Once the cap is on, gently pull each string end to make sure it feeds out smoothly. The string should slide out a few inches without catching. If it doesn't move, the string may not be seated in the slot correctly—unscrew the cap and reposition it.

Testing the trimmer after replacement

Start the engine and let it run at idle for a few seconds. Listen for any unusual sounds or vibration. If the trimmer sounds normal, increase the throttle slowly. The string should spin smoothly without wobbling or making a grinding noise.

If the string doesn't feed out or jams, stop the engine when ready and let it cool. Remove the cap and check that the string is seated in the feed slots. Tangled or bunched string is the most common problem, and it usually means the string was wound too loosely or in the wrong direction. Unwind it, rewind it tightly in the correct direction, and try again.

If the string feeds out but the trimmer vibrates badly, the string may be wound unevenly or the spool may not be seated properly in the head. Remove the cap, check that the spool is pushed all the way in, and make sure the string is wound evenly on both sides.

When to buy a pre-wound spool instead

If you find winding string tedious or if you use the trimmer frequently, buying a pre-wound replacement spool is faster and often more reliable. Ryobi sells replacement spools for most of their models, and they cost between $8 and $15. You straightforward unscrew the cap, remove the old spool, and snap in the new one. No winding required.

Pre-wound spools come with the string already wound at the factory in the correct direction and tension, so there's no risk of tangling or winding it backward. If you replace string more than a few times a year, the convenience usually pays for itself in time saved.

Frequently Asked Questions

Can I use string from a different brand in my Ryobi weed eater?

Yes, as long as it's the correct diameter. String is string—the brand doesn't matter. What matters is that the diameter matches what your trimmer head needs. Check your manual or the label on the head to confirm the size, then buy any brand that matches. Generic string from a hardware store works just as well as Ryobi-branded string and usually costs less.

What if I wind the string in the wrong direction?

The string will tangle and jam when you use the trimmer. Stop when ready, let the engine cool, and rewind it in the correct direction. Check the arrow on the spool before you start winding again. Winding backward is the most common mistake, and it's straightforward to fix—just unwind, turn the spool around, and wind it the other way.

How much string should stick out of the spool?

About 6 inches on each side. If you leave too much, it will flail around and may hit objects. If you leave too little, the trimmer won't feed string out correctly when the tip wears down. The 6-inch mark is a good middle ground that works for most Ryobi models.

Do I need to replace the spool itself, or just the string?

Usually just the string. The spool is plastic and lasts for years under normal use. Replace the spool only if it's cracked, warped, or if the notches where the string sits are worn smooth. If the spool looks fine, just wind new string onto it.

Why does my trimmer vibrate after I replace the string?

The string is probably wound unevenly or the spool isn't seated all the way into the head. Remove the cap and check that the spool is pushed firmly into place and that the string is wound tightly and evenly on both sides. Uneven winding creates an imbalanced load that causes vibration.