How To Change String On Stihl Fs 91 R

How To Articles

Today, I want to share my personal experience with changing the string on the Stihl FS 91 R trimmer. As a landscaping enthusiast, I have used various trimmers over the years, but the FS 91 R has quickly become one of my favorites. Not only is it powerful and reliable, but it also offers some user-friendly features that make maintenance tasks, such as changing the string, a breeze.

Gathering the Necessary Tools and Materials

Before diving into the process of changing the string, it’s important to gather all the necessary tools and materials to ensure a smooth and efficient operation. Here’s what you’ll need:

  • A replacement trimmer line spool
  • A pair of gloves for hand protection
  • A clean, flat surface to work on

Preparing the Trimmer

First, find a safe and well-ventilated area to work on your Stihl FS 91 R trimmer. It’s always a good practice to wear gloves to protect your hands from any sharp edges or debris. Once you’re ready, follow these steps:

  1. Turn off the trimmer and disconnect the spark plug wire to prevent accidental starting.
  2. Lay the trimmer on its side, ensuring the fuel tank cap is facing up to avoid any spills.
  3. Remove the trimmer head cover by turning it counterclockwise. This will give you access to the spool.
  4. Inspect the spool and remove any remaining trimmer line if necessary.

Replacing the Trimmer Line

Now that you have access to the spool, it’s time to replace the trimmer line. Follow these steps:

  1. Take your replacement trimmer line spool and locate the small hole in the center.
  2. Insert one end of the trimmer line into the hole, leaving a few inches of line sticking out.
  3. Carefully wind the trimmer line around the spool, following the arrow direction indicated on the spool. Make sure to keep the line tightly wound to avoid tangles.
  4. Leave a few inches of trimmer line unwound to ensure proper operation.
  5. Secure the end of the trimmer line in the notch or slot provided on the spool.

Finishing Up

Once you have replaced the trimmer line on the spool, it’s time to wrap up the process and get back to trimming those overgrown edges. Follow these final steps:

  1. Place the spool back into the trimmer head, ensuring it is properly aligned.
  2. Reattach the trimmer head cover by turning it clockwise until it’s securely in place.
  3. Connect the spark plug wire back to the trimmer.
  4. Clean up any debris or trimmings from your work area.


The process of changing the string on the Stihl FS 91 R trimmer may seem daunting at first, but with a little practice and attention to detail, it becomes a simple and quick task. By following the steps outlined in this article, you’ll be able to keep your trimmer in top shape and ready for any landscaping challenge that comes your way. Happy trimming!