FS 110 STIHL Manual

The FS 110 is a professional-grade string trimmer/brushcutter from STIHL, featuring a powerful 2-stroke engine, lightweight design, ergonomic handles, Easy2Start™ system, anti-vibration technology, and compatibility with various cutting attachments. Below are key sections for safety, features, operation, maintenance, and troubleshooting.

Features at a Glance

Key components: 2-stroke engine, Ergonomic loop handle, Shoulder strap attachment points, Anti-vibration system, Easy2Start™, Quick-release shaft coupling, Transparent fuel tank.

Feature	Description
Engine Type	2-stroke, single cylinder, air-cooled
Displacement	27.2 cm³ (1.7 cu. in.)
Power Output	0.9 kW (1.2 bhp)
Fuel Tank Capacity	0.53 liters (18 fl. oz.)
Weight (without cutting attachment)	5.2 kg (11.5 lbs)
Starting System	Easy2Start™ with decompression valve
Anti-Vibration System	Integrated dampers in handle and shaft
Shaft	Straight, steel drive shaft
Cutting Attachment Options	Trimmer head, circular brush knife, grass blade
Warranty	STIHL warranty terms apply

Safety Information

Read all instructions before operation. Wear appropriate PPE.

1. Personal Protective Equipment: Wear safety glasses, hearing protection, gloves, long pants, and sturdy boots.
2. Work Area Safety: Clear area of bystanders, especially children and pets. Be aware of hidden obstacles.
3. Fuel Safety: Refuel outdoors, engine off and cool. Use STIHL MotoMix® or proper 2-stroke mix. No smoking.
4. Operation: Hold unit firmly with both hands. Maintain secure footing. Do not operate above shoulder height.

WARNING! Rotating cutting attachments can cause serious injury or death. Keep hands and feet away. Never operate without proper guard installed.

Assembly & Preparation

Unpack and inspect contents. Assemble according to instructions.

1. Attach handle: Secure loop handle to shaft at desired position using provided bolts.
2. Install cutting attachment: Ensure engine is off. Attach trimmer head or blade, securing with retaining nut using appropriate wrench.
3. Install guard: Always install the correct cutting attachment guard before operation.
4. Attach shoulder strap: Connect strap to designated points on the unit for balanced operation.
5. Fuel mix: Use STIHL 2-stroke engine oil mixed with unleaded gasoline (50:1 ratio) or pre-mixed STIHL MotoMix®.

CAUTION! Ensure all fasteners are tightened securely before starting.

Specifications

• Engine: STIHL 2-MIX engine, 27.2 cm³.
• Fuel/Oil: Unleaded gasoline min. 89 octane with STIHL 2-stroke oil (50:1) or STIHL MotoMix®.
• Sound Power Level: 106 dB(A) (measured per ISO 22868).
• Vibration Levels: Left handle: 4.2 m/s², Right handle: 5.8 m/s² (measured per ISO 22867).
• Idle Speed: 2,800 rpm.
• Maximum Power Speed: 9,000 rpm.
• Recommended Cutting Attachments: STIHL PolyCut head, Circular Brush Knife, 3-tooth grass blade.
• Emissions Compliance: Meets EPA Phase 3 and CARS regulations.

Controls and Operation

Main Controls: Throttle trigger lockout, Throttle trigger, Stop switch, Choke lever, Primer bulb, Decompression valve.

Starting Procedure (Cold Engine):

1. Press fuel pump bulb at least 5 times.
2. Move choke lever to cold start position (full choke).
3. Press decompression valve (if equipped).
4. Place unit on firm ground. Hold handle firmly with one hand, press throttle trigger lockout and pull starter handle with other hand.
5. After engine fires, move choke lever to half-choke or run position.
6. Allow engine to warm up at idle for ~30 seconds before applying throttle.

Operation: Use a smooth, sweeping motion. Avoid forcing the tool. Let the cutting attachment do the work.

Fuel & Lubrication

Use fresh, clean fuel. STIHL recommends MotoMix® for optimum performance and reduced carburetor issues.

1. Fuel Mix (if mixing yourself): Use a clean, approved fuel container. Mix 50:1 ratio (2% oil). Add 2.6 fl. oz. of STIHL 2-stroke oil to 1 gallon of unleaded gasoline (min. 89 octane). Shake gently.
2. Refueling: Stop engine and allow to cool. Clean area around fuel cap. Fill tank, avoiding overfill. Tighten cap securely.
3. Gearbox Lubrication: Lubricate gearbox with STIHL gear oil after every 25 hours of operation or as needed.

Tip: Never use fuel older than 60 days. Drain fuel for long-term storage.

Cutting Attachments

Supports various STIHL-approved attachments.

1. Trimmer Head (PolyCut): For grass and light weeds. Tap head on ground to advance line (Tap-n-Go®).
2. Circular Brush Knife: For thick weeds and light brush up to 1/4 inch diameter.
3. 3-Tooth Grass Blade: For heavy grass and saplings.
4. Installation: Ensure unit is off. Use appropriate wrench to secure attachment. Always install matching guard.
5. Inspection: Check cutting attachment for damage, cracks, or excessive wear before each use. Replace if damaged.

WARNING! Always use the correct guard for the cutting attachment. Never operate with a damaged or missing guard.

Maintenance Schedule

Regular maintenance ensures performance and longevity.

Interval	Task
Before each use	Check for loose fasteners, damage. Inspect cutting attachment and guard.
Daily	Clean exterior. Check air filter, clean if dirty.
Every 25 hours	Clean spark plug. Check fuel filter. Lubricate gearbox.
Every 50 hours	Replace spark plug. Clean cooling fins. Check anti-vibration elements.
As needed	Replace air filter, fuel filter, starter rope.

CAUTION! Disconnect spark plug boot before performing any maintenance.

Storage Guidelines

Prepare unit for storage to prevent fuel system issues.

1. Drain fuel tank completely. Run engine until it stops to clear carburetor.
2. Remove spark plug, add a teaspoon of engine oil into cylinder. Pull starter rope slowly to distribute oil, then reinstall plug.
3. Clean entire unit thoroughly.
4. Store in a dry, secure place, out of reach of children.
5. Protect cutting attachment from corrosion with a light oil coating.

CAUTION! Never store unit with fuel in the tank for more than 30 days.

Warranty Information

STIHL Limited Warranty: Covers defects in materials and workmanship for a specified period from date of retail purchase. Proof of purchase required. Warranty does not cover normal wear, misuse, neglect, or use of non-STIHL parts/fuel. For complete warranty terms, see your STIHL Owner's Manual or visit www.stihlusa.com. For warranty service, contact an authorized STIHL servicing dealer.

Troubleshooting

Symptom	Possible Cause	Corrective Action
Engine will not start	No fuel, flooded, spark plug, switch off	Check fuel, dry spark plug, ensure stop switch is on, check for spark.
Engine starts then dies	Clogged fuel filter, dirty air filter, vent	Replace fuel filter, clean air filter, check tank vent.
Loss of power	Dirty air filter, clogged spark arrestor, old fuel	Clean/replace air filter, clean spark arrestor screen, use fresh fuel.
Excessive vibration	Damaged cutting attachment, loose parts	Inspect and replace damaged blade/head. Tighten all fasteners.
Line not advancing	Empty spool, tangled line, worn head	Refill spool with correct line, untangle, replace head if worn.

Service: For repairs beyond basic maintenance, take your FS 110 to an authorized STIHL dealer.

Support: 1-800-467-8445; www.stihlusa.com