How Long Should Trimmer Line Be? (It Does Matter)

You’ve loaded up your weed eater and installed the spool in your weed eater head. But now you’re wondering, how long should trimmer line be? How long should you make the two lines, and does it even matter? Well, before guessing, let me explain the correct length for the line.

How Long Should Trimmer Line Be (The Short Answer)

The weed eater line should be set to a long enough length to reach the deflector. Any excess line will be removed by the line cut-off knife that is located inside the weed eater head guard. To set the length correctly, you can use the auto-feed function of the head to feed the line, then allow the cut-off knife to trim the line to the correct length.

Does the Length of Your Trimmer Line Really Matter?

You’ll likely run into three different scenarios when it comes to getting the right line length on your weed eater. So, let’s take a look at what difference these lengths can make to your weed eater.

• Line that is Too Short
• Line that is the Correct Length
• Line that is Too Long (Without Guard)

Line that is Too Short

You’re probably already familiar with how your weed eater feels and acts when your line gets too short. Your weed eater cutting width gets smaller and smaller and stops cutting. In addition to this, your engine starts to rev higher and higher. This is because the engine is overspeeding without the drag of the line, which is definitely something you don’t want to do for too long unless you want to burn out your weed eater.

Line that is the Correct Length

When your trimmer line is set to the correct length, you’ll get the optimum line length for your weed eater engine and have the right amount of power for efficient trimming. In addition, you’ll avoid any engine damage caused by overspeeding.

Line that is Too Long (Without Guard)

If you have a guard installed on your weed eater, then your trimmer line will never be too long because the cut-off knife stops the line from reaching past a certain point. But weed eater guards are not compulsory to keep installed. So, if you remove the guard, you can have longer weed whacker lines. Because there is no limit to the length of the trimmer line without the cut-off blade, knowing how long the trimmer line should be is important. So, if your weed eater can handle the extra length of line, you’re good to go.

How to Tell if the Length of Your Trimmer Line Needs Adjusting

A few symptoms and signs will tell you if your weed whacker line is set to the correct length. Let’s take a look at what these are.

The Sound of the Engine

The engine will make two distinct sounds indicating the line is set at an incorrect length. An engine with a higher pitch sound indicates that the line is too short. In contrast, an engine with restricted revs indicates that the line is too long.

The Sound of the Line

If your line is too short, you might be able to hear a high pitch sound coming from the head of your weed whacker. Sometimes this can be the line and head overspeeding and causing an unusual high-pitch turbulence sound.

Now, if you have a line that is too long, then you’ll be able to hear the line spinning and causing a lot of turbulence. This tends to be a low pitch humming sound. You definitely want to take care of this before you put too much strain on your engine and the flex cable that connects the head to the clutch.

Cutting Efficiency

How long should the weed eater string be, and can you tell the difference? To start off, it’s pretty obvious when a trimmer line is short because the cutting area gets smaller and smaller with the reduced line. On the other hand, if your line is too long, your weed eater won’t have the power to straighten the line.

As a result, you’ll end up with the line spinning in a spiral that isn’t efficient at cutting. So if you are using your weed eater without a guard and you notice the grass isn’t being cut or is getting ripped apart, then your line is more than likely too long.

How to Set the Weed Eater Line Step-by-Step

Setting the correct length of the weed whacker line is actually pretty straightforward as weed whackers are designed to stop the line from getting too long. Well, that’s if you keep the guard attached. So, let’s go over the few steps you’ll need to follow to set the line correctly.

Weed Whacker With a Guard and Auto Feed Head

1. Install two new lines leaving two 6-inch tails
2. Bump the head a few times with the throttle pulled
3. Allow the line to auto-feed
4. Allow the cut-off knife to cut the two lines to the correct length
5. Inspect the weed eater line and ensure both lines reach the cut-off knife

Weed Whacker With a Guard and Without an Auto Feed Head

1. Install two new lines leaving two tails that are long enough to pass the cut-off knife
2. Throttle the engine and allow the head to spin
3. Allow the cut-off knife to cut the two lines to the correct length
4. Inspect the weed eater line and ensure both lines reach the cut-off knife

Weed Whacker Without a Guard and With an Auto Feed Head

1. Install two new lines leaving two 6-inch tails
2. Bump the head a few times with the throttle pulled
3. Allow the line to auto-feed
4. Check the engine can throttle fully without reduced power
5. Check the line can extend fully
6. Test the cutting ability
7. Repeat steps 2-6 to increase the line up to the point you feel a change in the performance of your weed eater. If you believe you have extended the line too far, you’ll need to cut off the excess line

Weed Whacker Without a Guard and Without an Auto Feed Head

1. Install two new lines leaving two 6-inch tails
2. Check the engine can throttle fully without reduced power
3. Check the Line can extend fully
4. Test the cutting ability
5. Manually increase the length of the line by 1 inch
6. Repeat steps 2-5 to increase the line up to the point you feel a change in the performance of your weed eater. If you believe you have extended the line too far, you’ll need to cut off the excess line