How to Put String in a Stihl FS 45 Trimmer

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Stihl FS 45 trimmers use nylon string, and that string can wear out quickly when trimming rough, rocky terrain or near hard-edged objects. This Stihl trimmer head requires restringing every now and then. Stihl uses easy spool trimmer heads on various curved- and straight-shaft weed trimmers, including some electric ones.


The Stihl FS 45 is a curved-shaft weed trimmer and uses the AutoCut C 6-2. With this trimmer head, Stihl has made it far easier to restring compared to earlier models that require wrapping the head with the nylon line while trying to hold it all together. Understanding what size line to use and how to store it will help you avoid frustration while using your Stihl curved-shaft weed trimmer.

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Things You'll Need

Reloading the Stihl Curved-Shaft Weed Trimmer

The AutoCut C 6-2 makes restringing your weed trimmer fast and easy so you can finish the job quicker.


Step 1: Shut Down the Weed Trimmer

Turn off the Stihl FS 45 trimmer and let the engine cool. Make sure the on/off switch is in the off position.

Step 2: Position the Trimmer

Put the trimmer on its engine with the curved-shaft end sticking up. This provides comfortable access to the trimmer head.

Step 3: Align the Arrows

The Stihl FS 45 trimmer head has a white inner ring and black outer ring. Push in on the white ring while holding the black ring. Align the four arrows on both rings with each other.


Step 4: Remove the Old String

You can pull out the old string once the arrows are aligned. If if doesn't come out, you will have to remove the trimmer head. Do this by holding the black outer ring of the trimmer head and unscrewing the center ring by turning the center nut counterclockwise. This may require the help of a large, flat-blade screwdriver. Once the center section is out, remove the old line. Reassemble the trimmer head by reversing the removal. Make sure the white ring moves freely and realign the arrows.


Step 5: Replace the Stihl String

Cut off 13 feet of Stihl trimmer nylon line. Push the nylon line through the AutoCut head until there are equal lengths on both sides of the head.

Step 6: Wind Up The Trimmer Line

Grip the black outer ring of the trimmer head and turn the white inner ring counterclockwise. Keep turning until the remaining line is to the edge of the guard; roughly 5 inches should be left. Trim any remaining line off.


About Stihl Weed Trimmer String

Every weed trimmer has a recommended size of nylon line to use, and the Stihl FS 45 trimmer is no exception. This Stihl trimmer can use up to .095 size line, which is a good-sized rugged line for those rocky trimming jobs. Most of the time, the .080 size will get the job done. Keeping your trimmer line stored in water and away from unwanted ultraviolet rays keeps it fresh and ready for work.



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