The STIHL FS 251 is a powerful and robust gas-powered trimmer designed for professional use. It is a heavy-duty machine that is well-suited for tackling tough trimming jobs, from clearing thick grass and weeds to cutting back brush. Here is a comprehensive review of the STIHL FS 251, including its specifications, starting instructions, troubleshooting tips, a comparison with the FS 251 R model, and information on trimmer head compatibility.

Advertisement
Contents hide
1 Demonstration Video
2 Specifications
3 How to Start the STIHL FS 251
4 Troubleshooting
5 STIHL FS 251 vs. FS 251 R
6 Trimmer Head Compatibility

Demonstration Video

For a look at the STIHL FS 251 in action, you can watch this YouTube video: My STHIL FS251 In Action! The video showcases the trimmer’s ability to effortlessly cut through tall, dense grass and overgrowth, providing a good visual representation of its power and performance.

Specifications

The STIHL FS 251 boasts impressive specifications that make it a top performer in its class:

  • Engine Displacement: 41.6 cc
  • Engine Power: 2.7 bhp
  • Weight: 15.2 lbs
  • Fuel Capacity: 25.4 oz
  • Cutting Width: 16.5 inches
  • Power Source: Gasoline
  • Shaft Design: Straight Shaft

How to Start the STIHL FS 251

Starting the STIHL FS 251 is a straightforward process:

  1. Prime the Fuel Pump: Press the fuel primer bulb at least five times. This will ensure that the carburetor has an adequate supply of fuel.
  2. Set the Choke: If the engine is cold, set the choke to the full choke position. If the engine has been recently run, you can set the choke to the warm start position.
  3. Pull the Starter Cord: Hold the trimmer securely and pull the starter cord until the engine attempts to start.
  4. Adjust the Choke and Start the Engine: Once the engine tries to start, move the choke to the run position and pull the starter cord again until the engine starts.

Troubleshooting

While the STIHL FS 251 is a reliable machine, you may occasionally encounter issues. Here are a few troubleshooting tips:

  • Throttle Cable Adjustment: Over time, the throttle cable may stretch, which can prevent the engine from reaching full throttle. You can easily adjust the cable by tightening a screw located at the bottom of the throttle handle to compensate for any slack.
  • Fuel Mixture: It is crucial to use the correct fuel mixture. The FS 251 requires a 50:1 mixture of gasoline to two-cycle engine oil. Using ethanol-free gasoline is recommended to prevent engine problems.
  • Consult the Manual: For any other issues, it is always best to consult the owner’s manual. The manual provides detailed troubleshooting information and maintenance guidelines.

STIHL FS 251 vs. FS 251 R

The primary difference between the STIHL FS 251 and the FS 251 R is the handlebar design:

  • STIHL FS 251: The FS 251 is equipped with bicycle-style handlebars. This design provides greater comfort and control when trimming for extended periods over large, open areas.
  • STIHL FS 251 R: The “R” in FS 251 R stands for “loop handle.” The loop handle makes the trimmer more maneuverable in tight spaces, such as between bushes, shrubs, and other obstacles.

Both models share the same powerful engine and cutting performance, so the best choice for you will depend on the type of trimming work you will be doing most often.

Trimmer Head Compatibility

The STIHL FS 251 is compatible with a variety of trimmer heads, allowing you to choose the best option for your needs. The standard trimmer head is the AutoCut C26-2, which is a “TapAction” head. This means you can extend the trimmer line by simply tapping the head on the ground.

The FS 251 is also compatible with other STIHL trimmer heads, including the DuroCut and TrimCut models. Additionally, there are aftermarket trimmer heads available that are compatible with the FS 251. Always ensure that the trimmer head you choose is rated for the power and RPM of the FS 251 to ensure safe and effective operation.