Stihl FS91R review - featured

Stihl FS91R Review

Stihl is one of the most requested string trimmers on the market when it comes to professional grades. It is a famous name brand associated with power and quality. As a user of Stihl string trimmers, I can tell you, the FS91R is one of the best, not only in my opinion, but it also finds itself on the top ten lists of many reviews. 


The Stihl FS91R is compared with its lineup and next of kin in the commercial string trimmers, the FS94R. Stihl has 12 professional weed eaters to compare, but we will compare the differences between the Stihl FS91R and the FS94R. Both have powerful motors, but the FS91R is the stronger of the two. Below are the notable differences. 

Engine Displacement28.4 cc24.1 cc
Engine Power.95 kW (1.27 bhp).9 kW (1.2 bhp)
Engine Type4-cycle2-cycle
Weight12.8 lbs10.1 lbs
Fuel Capacity24 oz18.3 oz
PriceCheck Price Check Price

Stihl FS91R has features such as the optional bike handle, IntelliCarb compensating carburetor, and a tool-free handle adjustment. The FS94R does not have these features. 


Stihl trimmer

The features listed are what make the Stihl FS91R stand out above the competitors. Many of these I find with comfort and ease of using the string trimmer. 

  • Environmentally Friendly with low exhaust emissions that are less than EPA and CARB exhaust emission standards
  • Made in America is the proud label that stands out above the rest.
  • A comfortable shoulder strap for easy carrying offers less fatigue for the user.
  • The fully lined drive shaft offers less vibration with smooth operation.
  • High-Tech Polymer Housing makes the weed eater lightweight and is corrosion resistant.
  • A protected choke lever prevents damage to the knob. 
  • A lock for the throttle trigger allows for cruise control. 
  • Easy to remove air filter cover for easy access
  • Secure control cables that are enclosed to prevent wire damage
  • Adjustable toolless front handle
  • The handle is also made of rubber and a loop handle to offer a better grip and control. 
  • The clutch is heavy-duty steel on steel design that helps to reduce slippage.
  • Secured Spark Arrestor Muffler minimizes the noise level, emissions, and sparks. 


The specs put this string trimmer at the top of my list regarding power and reliability. With the bigger engine, it is slightly heavier than some weed eaters, but the features of the adjustable front handle make up for the weight as it is easy to control. The shoulder strap also makes a huge difference in taking the weight off of the arms.   

  • Engine Displacement: 28.4cc (1.73 cubic inches) 
  • Power: 0.95 kW (1.27 bhp)
  • Weight: 5.8 kg (12.8 lbs.)
  • Fuel capacity of 24.0 oz. (710cc) Allows it to run 30 percent longer than the previous models. 
  • Cutting swath of 16.5 inches (41.91cm)
  • Gas engine
Stihl FS91R review - man cutting grass


As mentioned before, I am highly impressed with the power of the Stihl FS91R. It can cut almost through any tall grass while swinging the trimmer back and forth. The great news about it is, it has a fuel capacity of 710cc or 24.0 ounces. This information means you have a longer-lasting powerful tool to work with without having to stop to refuel as much. The information on the power is listed below. 

  • Engine Displacement: 28.4cc (1.73 cubic inches)
  • Horsepower: 1.27bhp (0.95kW)
  • The engine runs on gas. 


There are two things to take notice of the durability of this specific string trimmer. One is it is made in the USA! Two is the quality of material listed below in the parts that make up this excellent piece of equipment. 

  • It has a fully lined driveshaft to lessen the vibration while in full throttle.
  • It has a high-tech polymer housing that supports and protects the engine, wires, and small parts from the engine to the carburetor. 
  • There is a protected spark arrestor muffler that keeps fires from starting. 
  • The air filter cover is also worthy of mentioning as it protects the air filter compartment and the air filter with easy access for changing the filter. 
Stihl FS91R review - FS91R trimmer


Earlier, we mentioned the weight of the string trimmer was 12.1 pounds or 5.5kg. It is compared with other weed eaters as a medium weight capacity or average, which is 10-12lbs. There is no denying, today's string trimmers have been built with less weight and more power. I remembered 20 something years ago, a powerful four-cycle string trimmer weighed close to 15-17 pounds. Now, the engines are more compact with more power than they ever had before. 

Pros / Cons 

All pieces of equipment in the residential and commercial sector have good and bad points. These are some of what we noticed to deliver the perfect Stihl FS91R review.


  • Robust, reliable, and durable
  • Great customer service
  • If properly maintained, it can last a long time, 5-7 years lifespan, if not more. 
  • Easy to maintenance
  • Excellent warranty
  • Little to no vibration
  • Usually starts on the first crank.
  • Lightweight for the amount of power
  • Easy to maneuver with the handle and straight shaft
  • Holds 30 percent more fuel than other weed eaters
  • Fuel efficient 


  • In some cases, it may be too much power. It can do a lot of damage if the string hits something it shouldn't.
  • Some reports have stated the fuel gets caked up in the carburetor. We recommend non-ethanol fuel with a fuel treatment. 


There is a two-year warranty on the string trimmer. Compared to other commercial weed eaters, this is relatively good news. Most weed eaters in the commercial sector of the competitors usually have a one-year warranty. This is also another guarantee added to the Stihl label on its reliability.

Our Rating

Performance:4.3 out of 5 stars (4.3 / 5)
Weight:4 out of 5 stars (4.0 / 5)
Durability:4.5 out of 5 stars (4.5 / 5)
Comfort:4.3 out of 5 stars (4.3 / 5)
Price:4 out of 5 stars (4.0 / 5)
Overall:4.2 out of 5 stars (4.2 / 5)


This string trimmer is sold at a very reasonable price for a commercial machine. Overall, the FS91R is one of the most popular weed eaters on the market so it commands a price that may be a little higher than others.

Wrapping It Up

As you all can see, this string trimmer packs a hefty punch and is perfect for commercial and residential use. The Stihl FS91R is a string trimmer you can rely on between the features, specs, and everything in between. 

What Do You Think?

I hope this Stihl FS91R review has helped you decide to get one yourself. Do you own one already? Let us know in the comments!

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Images are from Stihl.

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