The Basic Process for Ryobi Trimmer Line Replacement

To replace the line on a Ryobi trimmer, you stop the engine, let it cool, then unscrew the spool cap at the head of the trimmer, remove the old spool, wind new line onto it in the correct direction, and reinstall it. The whole job takes about five minutes once you have the right line diameter for your model. Most Ryobi trimmers use either 0.065-inch or 0.080-inch line, and using the wrong size will cause the line to slip or break repeatedly.

The exact steps depend slightly on whether your trimmer has a fixed spool (the kind you wind by hand) or an auto-feed spool (the kind that advances line automatically as it wears). Both are straightforward, but the winding direction matters—wind it the wrong way and the line will unwind as soon as you start the engine.

Key Takeaways

  • Check your trimmer's model number on the housing to find the correct line diameter—Ryobi trimmers commonly use 0.065-inch or 0.080-inch line, and using the wrong size causes slipping and breakage.
  • Always wind the line in the direction indicated by the arrow molded into the spool itself, or the line will unwind when you start the engine.
  • For a fixed spool, wind the line tightly in overlapping passes, leaving about 6 inches free on each side to thread through the eyelets.
  • For an auto-feed spool, insert the line into the small slot at the center, wind it around the spool, and the trimmer will feed it automatically as it wears.
  • After reinstalling the spool, test the line by running the trimmer briefly at low speed before cutting to make sure it feeds correctly.

Finding the Correct Line Size for Your Model

The first step is knowing which line diameter your trimmer needs. Look at the housing of your trimmer—usually near the spool head or on the underside—for a model number like RY40200 or RY40210. Write this number down and search for it on the Ryobi website or in your owner's manual. The manual will list the line diameter in the specifications section.

If you have lost the manual, you can also look at the spool itself. Many Ryobi spools have the correct diameter printed or molded into the plastic. Common sizes are 0.065 inch (the thinner, lighter line for light grass) and 0.080 inch (thicker, for tougher weeds and brush). Buying the wrong size is the most common mistake—the line either slips inside the spool or does not fit at all.

Buy trimmer line at any hardware store, garden center, or online. A standard spool of line is usually 30 to 50 feet long and costs between $3 and $8. You do not need to buy a Ryobi-branded spool; any line of the correct diameter will work.

Removing the Old Spool and Cap

Turn off the trimmer and let the engine cool for at least five minutes. If you have just been using it, the spool head will be hot enough to burn your hand. Once it is cool, locate the spool cap—a round plastic cover at the very top of the trimmer head.

Most Ryobi trimmers have a cap that unscrews by hand. Turn it counterclockwise (to the left) until it comes free. Some models have a small notch or flat spot on the cap; if yours does, use a flat-head screwdriver to turn it. Once the cap is off, the spool should lift straight out. If it sticks, wiggle it gently side to side while pulling upward.

Before you throw away the old spool, check whether it is reusable. If it is cracked or the winding grooves are damaged, you will need to buy a replacement spool as well as line. Ryobi sells replacement spools for about $5 to $10. If the spool is intact, you can wind new line onto it.

Winding Line on a Fixed Spool

A fixed spool is the simpler type—it is just a plastic spool with no moving parts. Look at the spool and find the arrow molded into the plastic. This arrow shows you the direction to wind the line. This is critical: if you wind it backward, the line will unwind as soon as the trimmer runs.

Cut a length of line about 20 to 25 feet long. Hold the spool in one hand and the line in the other. Starting at the center of the spool (where the cap screws on), insert the line into the small notch or slot there. Wind the line tightly around the spool in the direction the arrow points, making sure each pass overlaps the previous one slightly so the line does not slip.

Keep winding until you have used most of the line, leaving about 6 inches free on each side. Do not overstuff the spool—if the line is packed too tightly, it will jam when you try to feed it through the eyelets. The line should sit neatly in the grooves with a little room to spare. Once you have wound it, tuck the free ends into the small notches on the sides of the spool (most Ryobi spools have these notches to hold the line in place while you reinstall the cap).

Loading Line on an Auto-Feed Spool

An auto-feed spool looks different—it has a small slot or hole at the center and sometimes a spring underneath. These spools advance the line automatically as it wears, so you do not have to manually feed it as often. The winding process is similar, but the starting point is different.

Cut a length of line about 20 to 25 feet long. Look for the small slot at the center of the spool (it is usually labeled with an arrow or a small icon). Insert one end of the line into this slot and push it in until it catches. Now wind the line around the spool in the direction indicated by the arrow, making sure it sits neatly in the grooves.

Wind until you have about 6 inches of line left free. Some auto-feed spools have a small notch on the rim where you tuck the free end to keep it from unwinding. If your spool has one, use it. If not, hold the line in place with your thumb while you reinstall the cap.

Reinstalling the Spool and Cap

Once the line is wound, lower the spool back onto the shaft inside the trimmer head. It should sit flat and spin freely. If it does not spin, the line may be wound too tightly or the spool may not be seated correctly. Lift it off and check that the center hole is aligned with the shaft.

Thread the free ends of the line through the two eyelets (the small holes on the sides of the trimmer head where the line exits). Pull each end until about 4 to 6 inches of line sticks out on each side. This is the cutting length—the part that actually touches the grass.

Screw the cap back on by turning it clockwise (to the right) until it is snug. Do not overtighten it; you only need it tight enough that it does not come loose during use. If you overtighten it, you risk cracking the plastic.

Testing the Line Before You Cut

Before you start trimming, run the trimmer briefly at low speed to make sure the line feeds correctly. Start the engine and let it idle for about 10 seconds. Listen for any grinding or jamming sounds. If the line is wound backward or jammed, you will hear it when ready.

If the line does not feed smoothly, stop the engine, let it cool, and remove the cap again. Check that the line is wound in the direction the arrow points. If it is, the line may be too tightly wound or there may be a knot in it. Unwind a few passes, loosen the line slightly, and try again.

Once the trimmer runs smoothly at idle, increase the speed gradually. The line should rotate without wobbling or hitting the guard. If everything looks and sounds right, you are ready to cut.

Common Mistakes to Avoid

The most common mistake is winding the line backward. Always check the arrow on the spool before you start. The second most common mistake is using the wrong line diameter. If the line keeps slipping or breaking after just a few minutes of use, stop and check the size. A 0.065-inch line will not stay in a spool designed for 0.080-inch line.

Another frequent error is leaving too much line sticking out of the eyelets. If more than 6 inches of line is exposed, it will whip around and hit the guard, which slows the trimmer and wears the line faster. Conversely, if you leave too little line, the trimmer will not cut effectively. Aim for about 4 to 6 inches on each side.

Finally, do not wind the line so tightly that it jams. The line should sit neatly in the grooves with a little room to move. If you have to force the cap on, you have wound it too tightly. Unwind a few passes and try again.

Frequently Asked Questions

What line diameter does my Ryobi trimmer use?

Check your owner's manual or the model number on the trimmer housing. Most Ryobi trimmers use either 0.065-inch or 0.080-inch line. You can also look at the spool itself—many have the diameter printed on them. If you are still unsure, take the model number to a hardware store and staff can tell you which size to buy.

Can I use a different brand of line on my Ryobi trimmer?

Yes. As long as the line is the correct diameter, any brand will work. Ryobi-branded line is not required. Buy whatever is available at your local store or online, as long as it matches the diameter your trimmer needs.

How often do I need to replace the line?

It depends on how often you use the trimmer and what you are cutting. Light grass use might get you several weeks per spool. Heavy brush or frequent use might require a new spool every week or two. You will know it is time when the line becomes noticeably shorter or thinner, or when the trimmer stops cutting cleanly.

What should I do if the line keeps breaking?

First, check that you are using the correct diameter for your model. If you are, the line may be wound too tightly, wound backward, or jammed against the guard. Remove the spool, loosen the line slightly, and make sure it is wound in the direction the arrow points. Also check that the guard is not bent or cracked—a damaged guard can catch and break the line.

Do I have to buy a new spool, or can I reuse the old one?

You can reuse the old spool as long as it is not cracked or damaged. If the winding grooves are worn smooth or the spool is broken, you will need to buy a replacement. Replacement spools are inexpensive—usually $5 to $10—and last for many line changes.