STIHL® FS 91

• Power Source
• Type: Gas
• Engine Specifications
• Engine Power: 1.27 bhp
• Displacement: 28.4 cc
• Cutting & Performance
• Cutting Width: 16.5 in.
• Fuel & Capacity
• Fuel Capacity: 24.0 oz.
• Weight
• Tool Weight: 12.8 lbs.

What is the STIHL FS 91 trimmer?
The STIHL FS 91 is a professional gas-powered trimmer designed for mowing, heavy grass trimming and demanding landscape-maintenance work.

Who is the STIHL FS 91 best suited for?
It is ideal for professional landscapers, grounds crews, acreage owners and property-maintenance teams who need a durable trimmer for regular heavy use.

What engine does the STIHL FS 91 use?
It uses a 28.4cc low-emission gas engine.

How much power does the STIHL FS 91 produce?
The listed engine output is approximately 1.27 bhp.

What is the cutting width of the STIHL FS 91?
It has a cutting width of approximately 16.5 inches.

What is the fuel capacity?
The fuel tank holds approximately 24 oz.

How does the FS 91 compare with the previous model?
STIHL states that its larger fuel tank provides approximately 30% longer runtime than the previous model.

Does the STIHL FS 91 require mixed fuel?
Yes. It uses gasoline mixed with approved two-stroke engine oil according to STIHL specifications.

What type of handle does the STIHL FS 91 use?
It uses a bike-style handle with redesigned rubberized grips.

Why is the bike handle useful?
It provides better leverage and supports a smooth side-to-side mowing motion across larger areas.

Can the bike handle be adjusted without tools?
Yes. A central wing nut allows tool-free handle adjustment.

Can the handle be rotated for storage or transport?
Yes. It can rotate approximately 90 degrees to reduce the machine’s width.

Should the STIHL FS 91 be used with a harness?
Yes. A compatible harness or shoulder carrying system helps distribute the machine’s weight and improve control.

What are the benefits of using a harness?
It transfers part of the load from the hands and arms to the shoulders, helping reduce fatigue during longer jobs.

What cutting head comes with the STIHL FS 91?
The supplied information lists a TapAction AutoCut cutting head, but the exact package contents should be confirmed before purchase.

How does the TapAction AutoCut head work?
The operator taps the cutting head on the ground while it is running to advance additional trimmer line.

Can the STIHL FS 91 use metal blades?
Yes. Its solid steel drive shaft accepts a range of approved heavy-duty cutting heads and metal blades.

Can the STIHL FS 91 be used for brush clearing?
Yes. With the correct approved metal attachment, it can handle thick weeds, dense grass and light brush.

Can it cut small saplings?
It may handle small woody growth with an approved blade, but it is not a replacement for a clearing saw or chainsaw.

What is the solid steel drive shaft?
It transfers engine power to the cutting attachment and supports heavier-duty cutting applications.

What is the fully lined drive shaft?
The shaft is internally lined to promote smoother operation and reduce vibration.

Does the STIHL FS 91 have an anti-vibration system?
Yes. The anti-vibration system helps reduce vibration transferred to the operator.

Why is reduced vibration important?
It improves comfort and can help reduce fatigue during extended professional use.

What is STIHL IntelliCarb technology?
The IntelliCarb compensating carburetor adjusts fuel metering as the air filter becomes dirty, helping maintain more consistent engine speed.

Does IntelliCarb eliminate air-filter maintenance?
No. The air filter still needs regular inspection, cleaning and replacement.

Is the air filter easy to access?
Yes. The removable air-filter cover allows faster cleaning or replacement.

How does the STIHL FS 91 start?
The simplified procedure involves pressing the primer, setting the semi-automatic choke and pulling the starter cord.

Does the STIHL FS 91 have electric start?
No. It uses a recoil pull-start system.

What is the one-touch stop feature?
The stop switch shuts off the engine with one press and automatically returns the controls to the starting position.

What is the purge pump primer?
The primer delivers fuel to the carburetor, helping reduce the number of starter pulls after the machine has been sitting.

Where are the operating controls located?
The main start, run, stop and throttle controls are built into the multi-function control handle.

What is the throttle trigger interlock?
It is a safety control that must be pressed before the throttle trigger can be activated.

What is the heavy-duty steel-on-steel clutch?
It is a centrifugal clutch designed to reduce slippage under demanding loads.

What is the upright translucent fuel tank?
The clear tank makes it easier to check the fuel level and refill the machine.

Does the STIHL FS 91 have protected control cables?
Yes. The cables are enclosed to reduce snagging and accidental damage.

Is the spark plug protected?
Yes. It is shielded from damage while remaining accessible for replacement.

Is the choke control protected?
Yes. The choke lever is positioned to help prevent accidental damage.

What is the protected spark-arrestor muffler?
It contains baffles and a screen designed to reduce noise and limit the release of sparks.

What is the high-tech polymer housing?
The housing uses lightweight, impact-resistant and corrosion-resistant polymer materials.

How much does the STIHL FS 91 weigh?
The listed tool weight is approximately 12.8 lb.

Does the listed weight include fuel and the cutting attachment?
The supplied information does not specify this clearly. Actual operating weight will depend on the attachment, harness and fuel level.

Is the STIHL FS 91 suitable for large properties?
Yes. Its professional engine, bike handle and 16.5-inch cutting width make it well suited to acreages and larger properties.

Can it be used for regular lawn trimming?
Yes. It can handle standard grass trimming as well as heavier vegetation when fitted with the correct attachment.

Is the STIHL FS 91 suitable for noise-sensitive areas?
It is a gas-powered machine, so a battery trimmer may be a better choice where reduced noise is important.

Does the STIHL FS 91 produce exhaust emissions?
Yes. It is gas powered, although the engine is designed to produce lower emissions than older engine designs.

What maintenance does the STIHL FS 91 require?
Routine care includes checking the air filter, spark plug, fuel system, cutting attachment, gearbox, clutch, guard and starter.

Should the cutting attachment be inspected before use?
Yes. Check the head or blade for wear, cracks, damage and secure installation before each job.

What protective equipment should be worn?
Wear eye and face protection, hearing protection, gloves, long pants, sturdy boots and suitable protective clothing.

Are the listed dimensions complete?
No. The secondary table lists zero values for width, height and length. Those entries should be removed or corrected before publishing.

What are the main benefits of the STIHL FS 91?
Its main benefits include a professional 28.4cc engine, bike handle, anti-vibration system, IntelliCarb technology and compatibility with approved metal blades.

Where can I buy the STIHL FS 91 trimmer in Canada?
The STIHL FS 91 trimmer is available in store from Arns Equipment in Calgary or online across Canada at arns.ca.