FS 100 RX

FS 100 RX
A professional grass trimmer that delivers big power in a lightweight package.

Model Features

  • Reduced-Emission Engine Technology - Caring for Nature
    The STIHL Inc. “Caring for Nature” seal identifies its powered products that are more environmentally conscious, producing zero or low exhaust emissions. STIHL Inc. defines “low exhaust emissions” as being cleaner than EPA and/or CARB exhaust emission standards.

    More information

  • Built in the USA
    Indicates products that are built in the United States from domestic and foreign parts and components.

    More information

  • Cutting Heads & Blades Selection Chart
    Need help selecting a cutting head or blade for your STIHL trimmer or brushcutter?

    Click here to view the Cutting Heads & Blades Selection Chart (PDF Format).
  • Loop Handle (R)
    Loop handle grass trimmers and brushcutters are ideal for trimming between bushes and shrubs and other areas where space is limited.
  • Shoulder Strap / Carrying System
    Using a shoulder strap or carrying system helps distribute the weight of the equipment for increased operator comfort and improved maneuverability.
  • Multi-Function Control Handle
    Having easy access to all of the controls on one comfortable handle makes it easy to complete tasks so the operator’s hand never has to leave the handle.
  • Purge Pump Primer
    By pressing the bulb, this small fuel pump delivers fuel to the carburetor, reducing the number of starting pulls needed after an extended break between uses.
  • Upright Translucent Fuel Tank
    Allows operator to easily check fuel level before starting work. Upright position makes it easier to refill.
  • Protected Spark Arrestor Muffler
    Has large baffles which reduce noise level and contains a screen designed to reduce the emission of sparks.
  • Protected Spark Plug
    Protected yet easy to change.
  • Heavy-Duty Steel-On-Steel Clutch
    Centrifugal clutch is designed to reduce slippage.
  • Protected or Enclosed Control Cables
    Eliminate dangling and loose wires.
  • Air Filter Cover
    Easily removed for fast and easy filter cleaning or replacement.
  • Throttle Trigger Interlock
    Must be depressed before the trigger can be activated.
  • Start/Run/Stop Controls on Handle
  • Protected Choke Lever/Knob
    Helps prevent damage.
  • High Tech Polymer Housing
    Housings are lightweight, withstand greater impact and are corrosion-resistant.
  • Fully Lined Drive Shaft
    Provides smooth operation and less vibration.
  • Adjustable Front Handle
    Adjusts for comfort.


31.4 cc (1.9 cu. in.)
1.05 kW (1.4 bhp)
4.9 kg (10.8 lbs.)
530 cc (18.0 oz.)
*Weight without cutting attachment or deflector.

Important Information

WARNING! Improper use of any trimmer/brushcutter can cause serious or fatal injury. Read, understand and follow all safety instructions in your instruction manual. To reduce the risk of injury from blade contact, circular saw blades may be used on FS brushcutters that have a limitstop, a bicycle handle and double shoulder harness and not on FS brushcutters with a "J" handle or loop handle. Other rigid blades may be used on FS brushcutters having a bicycle handle, a "J" handle or a loop handle equipped with a barrier bar. To reduce the risk of eye injury always wear proper eye protection. Always use the appropriate deflector for the type of cutting attachment, as explained in your instruction manual.

Note: STIHL engine products with the Caring for Nature logo are cleaner than EPA Standards for exhaust emissions.

Note: STIHL recommends use of fuel with no more than 10% Ethanol content. Using fuel with greater than 10% Ethanol content may cause damage to your equipment and may void your STIHL warranty. Learn More…

WARNING! Improper use of any power tool may cause serious or fatal injury. Read, understand and follow carefully the operating and safety instructions in your instruction manual before using such products.

STIHL products sold through U.S. STIHL Dealers are for distribution in the United States only.


FS 100 RX is rated 4.5 out of 5 by 67.
Rated 2 out of 5 by from Poor Dealer Product Knowlege and Parts Support It's a good enough trimmer I suppose. The employees at ACE the hardware store where I bought it knew nothing about it. They happily sold me a brush cutter blade with it even though it could not be used with this model (which was a prime reason I bought it). Of course by the time I found this out, I had used the trimmer and it was not returnable...Also, it's 2017. Why can't I buy parts online, or at least look them up to order them and have them shipped to a dealer? Every time I need an out of stock part, I have to make two trips to the dealer, once to order it and once to pick it it. Not convenient when you live a ways out of town. Most people are more than capable of matching up a picture of a part to what they need and ordering it...All in all a decent product but the whole Stihl experience (parts and dealer support) is lacking.
Date published: 2017-01-10
Rated 5 out of 5 by from A beast of a trimmer I recently purchased the Stihl FS 100 RX for my lawn care business. I was looking for a trimmer with plenty of power and torque for regular trimming as well as heavy duty trimming. I also wanted a lightweight trimmer that wouldn't wear me out by the end of the day. I was able to find all of those qualities in the Stihl FS 100 RX. I have no issues using this trimmer for weekly lawn maintenance as well as heavy duty grass clearing jobs. It is definitely one beast of a trimmer that will be a very valuable item in my lawn care business.
Date published: 2016-11-20
Rated 5 out of 5 by from Impressive Trimmer This trimmer is very impressive. It is very very powerful. I am 15 years old and am still getting used to this power. I mow quite a few lawns every week, so I needed to buy a reliable trimmer. I use this for trimming and edging and it works great.
Date published: 2016-11-09
Rated 4 out of 5 by from Works great....but Light weight, powerful. It does throw grass on you as you use. Don't like that. Overall I like it.
Date published: 2016-09-14
Rated 5 out of 5 by from Amazing My favorite trimmer in my fleet. It's my go to trimmer
Date published: 2016-08-28
Rated 5 out of 5 by from Great heavy duty trimmer Finally had to upgrade to a professional trimmer for my new property. Went with this after testing several brands and models at our organic farm. Few months old now, have run it several times for multiple hours, and it eats everything in its path, including saplings. Light weight and powerful, it's a pleasure to use this trimmer!
Date published: 2016-08-16
Rated 5 out of 5 by from Great trimmer! I purchased this trimmer 2 weeks ago and I was blown away! Tremendous power and versatility. Owned another brand for 15+ years. I didn't realize want a great trimmer was until I started this beast! I'll be back!
Date published: 2016-08-04
Rated 1 out of 5 by from Lacks power!!! This trimmer is like using a pair of scissors compared to my echos. I haven't owned it long enough to see how dependable it is. I suppose it's good if you use it for only weekly yards. I do like how it's light weight, but that's about it. I bought this solely for the light weight compared to my echos, but was disappointed when I bought this similar sized trimmer as my srm-266 only to find out it had half the power.
Date published: 2016-08-04
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Standard Features

  • Common Features for Trimmers
    View the features common to many STIHL trimmers.

You Will Also Need

For Your Safety


How to Wind a STIHL Trimmer Head - Video
How to Start Your FS 100 RX Trimmer - Video
Cutting Heads & Blades Selection Chart (PDF)
Download Instructions on How to Rewind Your Trimmer Head (PDF)
Product Instruction Manual (PDF)
Product Safety Manual (PDF)
STIHL Limited Warranty
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