Ryobi trimmers use a straightforward two-step process to swap out old line for new

Most Ryobi string trimmers have a bump-feed head that holds the line in a spool. To replace the line, you unscrew the spool cap, remove the old spool or wind out the remaining line, insert new line into the slots, and screw the cap back on. The whole job takes about five minutes once you have the right replacement line on hand.

The exact steps depend on whether your trimmer has a fixed spool or a removable one. Both types are common in the Ryobi line. This guide covers both, plus what size line to buy and what to do if the head won't turn or the line won't feed.

Key Takeaways

  • Ryobi trimmers typically use 0.065-inch or 0.080-inch diameter line, printed on the spool or in your manual — buying the wrong size wastes money and may not fit.
  • The spool cap unscrews by hand or with a wrench, depending on your model, and the old line either pulls out or stays in the head while you wind new line onto it.
  • New line must be inserted into the two slots on the spool in the correct direction, or it will not feed when you bump the head on the ground.
  • If the spool spins freely but line does not come out, the line is probably wound the wrong way or not seated in the slots.

Find the right line diameter for your model

Ryobi trimmers come in different sizes, and each one takes a specific line diameter. The most common sizes are 0.065 inch and 0.080 inch. Check your trimmer's manual or look at the spool itself — the diameter is usually printed on a label or molded into the plastic.

If you cannot find the size, look up your model number on the Ryobi website or call their customer service line. Buying line that is too thick will not fit into the head. Line that is too thin will slip and not cut properly. Most hardware stores and online retailers sell Ryobi-branded line, which is may provide to fit, but universal trimmer line in the correct diameter will work just as well and often costs less.

Remove the spool cap and old line

Locate the spool cap at the bottom of the trimmer head. On some models, it unscrews by hand — grip it firmly and turn counterclockwise. On others, you will need a wrench or socket to loosen it. Check your manual if you are not sure which type you have.

Once the cap is off, you will see the spool. On removable-spool models, the entire spool lifts out. On fixed-spool models, the spool stays in place. Either way, pull out any remaining line or unwind it by hand. If line is stuck, a gentle tug usually frees it. Do not force it — if it will not budge, the spool may be damaged and need replacement.

Insert new line into the spool slots

Look at the spool. You will see two small slots or notches on opposite sides where the line feeds through. This is where the new line goes. Cut a length of new line — most spools hold 15 to 25 feet, but check your manual for the exact amount. A good rule of thumb is to cut more than you think you need; you can always trim the excess.

Insert one end of the line into one slot and push it all the way through until it comes out the other slot. The line should sit snugly in both slots. If it is loose or falls out, you may have the wrong diameter. Once both ends are seated, wind the line onto the spool by turning it by hand. Wind in the direction marked on the spool — usually an arrow shows which way to go. Wind tightly and evenly, keeping tension on the line as you go. Leave about 4 to 6 inches of line sticking out on each side when you are done.

Screw the cap back on and test

Once the line is wound, screw the spool cap back on by hand or with a wrench, depending on your model. Tighten it firmly but do not over-tighten — you should be able to unscrew it again without straining. If the cap has a notch or slot, line it up with the matching mark on the head so the line feeds out correctly.

Before you use the trimmer, hold it over a trash can and bump the head gently on the ground a few times. This activates the bump-feed mechanism and should release a small amount of line. If line does not come out, the spool may be wound the wrong direction or the line is not seated in the slots. Unscrew the cap and check. If line comes out smoothly, you are ready to trim.

Troubleshoot common problems

If the spool spins freely but no line comes out, the line is probably wound backward. Unscrew the cap, check the direction arrow on the spool, and rewind if needed. Another common cause is line that is not fully seated in the slots — it can slip out during winding. Remove the cap and push both ends of the line firmly into their slots, then try again.

If the cap will not unscrew, do not force it. Spray a small amount of penetrating oil around the threads and wait a few minutes. Then try again with a wrench for better grip. If the spool itself is cracked or the slots are damaged, the spool will need to be replaced — contact Ryobi for a replacement part.

If line keeps breaking or shredding during use, you may have the wrong diameter or the line may be wound too loosely. Check the diameter against your manual and rewind with more tension. If the head is hitting rocks or hard objects, that can also damage the line — try to keep the trimmer head just above the ground.

When to replace the entire head

Most of the time, you only need to replace the line. But if the spool cap cracks, the spool itself breaks, or the head stops feeding line even after you have reloaded it correctly, the entire head may need replacement. Ryobi sells replacement heads that fit most of their trimmer models. Check your manual or the Ryobi website to find the right head for your model.

Replacement heads are usually cheaper than buying a new trimmer and take about the same amount of time to install. You will typically need to unscrew a few bolts on the shaft and slide the old head off, then slide the new one on and tighten the bolts. If you are not comfortable doing this, a local repair shop can do it for you.

Frequently Asked Questions

How often do I need to replace the line?

It depends on how often you trim and what you are cutting. If you trim weekly in a small yard, you might go through line every few weeks. Heavy use or hitting rocks and hard objects will wear line faster. Keep extra spools on hand so you can reload quickly when you run out.

Can I use line from a different brand?

Yes, as long as it is the correct diameter for your trimmer. Universal trimmer line works fine and is often cheaper than Ryobi-branded line. Just make sure the diameter matches what your manual says.

What if I wind the line the wrong way?

The trimmer will not feed line when you bump the head. straightforward unscrew the cap, check the direction arrow on the spool, and rewind the line in the correct direction. It only takes a few minutes to fix.

Do I need to remove the battery before replacing the line?

It is a good safety practice to remove the battery before working on the trimmer head, even though the head will not spin without the battery. This prevents accidental startup if you bump the trigger.

Can I use thicker line to cut tougher weeds?

No. Using line thicker than your manual specifies will not fit in the head and can damage the feed mechanism. If you need to cut tougher plants, use the correct line diameter and let the trimmer do the work — do not force it.