STIHL FS 106 Manual

The STIHL FS 106 is a lightweight, straight-shaft grass trimmer/brushcutter designed for residential and professional use. It features a 2-stroke engine with electronic ignition, a loop handle for comfortable operation, a tap-and-go trimmer head for easy line advancement, a debris-deflecting metal shield, and a bicycle-style throttle trigger. Below are key sections for safety, features, operation, maintenance, troubleshooting, and specifications.

Features at a Glance

Key components: 2-stroke engine, Straight shaft, Loop handle, Throttle trigger with lockout, Stop switch, Metal debris shield, Tap-and-go trimmer head, Fuel tank, Primer bulb.

Feature	Description
Engine Type	STIHL 2-stroke, single cylinder, air-cooled
Displacement	27.2 cm³ (1.66 cu. in.)
Power Output	0.9 kW (1.2 bhp)
Fuel System	Diaphragm carburetor with manual choke
Ignition System	Electronic, non-adjustable
Starting System	Rewind starter with decompression valve
Shaft	Straight, solid drive shaft
Handle	Loop handle with vibration damping
Cutting Attachment	Standard tap-and-go trimmer head for line
Weight (without cutting attachment)	Approx. 5.2 kg (11.5 lbs)

Safety Instructions

Read and understand all instructions before use. Always wear proper PPE.

1. Personal Protective Equipment (PPE): Always wear safety glasses, hearing protection, sturdy gloves, long pants, and closed-toe shoes.
2. Clear Work Area: Remove stones, sticks, wire, and other debris before operation.
3. Fuel Safety: Refuel outdoors only, with engine stopped and cool. Use STIHL MotoMix or proper gasoline/oil mixture.
4. Operation: Keep bystanders and pets at least 15 meters away. Hold unit firmly with both hands.
5. Transport: Carry unit with engine stopped, cutting attachment covered, and away from body.

WARNING! Risk of serious injury or death from blade thrust, thrown objects, and carbon monoxide poisoning. Never operate indoors or in poorly ventilated areas.

Assembly & Preparation

Unpack and inspect contents. Assemble handle, attach cutting tool, and add fuel.

1. Handle Assembly: Attach loop handle to shaft at desired position using supplied hardware.
2. Cutting Attachment: Install standard trimmer head or optional blade according to instructions, ensuring it is securely fastened.
3. Fuel Mix: Use STIHL 2-stroke engine oil mixed with unleaded gasoline (min. 89 octane) at a 50:1 ratio (or as specified for your oil). Shake well in approved fuel can.
4. Priming: Press primer bulb 5-10 times until fuel is visible in the bulb.
5. Starting Position: Place unit on firm, flat ground. Engage the chain brake (if applicable) or ensure cutting attachment is clear.

CAUTION! Ensure all fasteners are tight before operation. Do not use damaged parts.

Specifications

• Model: STIHL FS 106.
• Engine Power: 0.9 kW (1.2 bhp).
• Displacement: 27.2 cm³.
• Fuel Tank Volume: 0.47 liters (0.12 US gal).
• Oil Tank Volume: (For gearbox) 0.05 liters.
• Sound Pressure Level: Approx. 96 dB(A).
• Vibration Level: Left/Right handle: Approx. 4.5/6.5 m/s².
• Max. Recommended Cutting Diameter (Line): 430 mm (17 in).
• Drive System: Solid steel shaft with spiral bevel gears.
• Warranty: Limited warranty, terms vary by region.

Controls and Operation

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

Starting Procedure (Cold Engine):

1. Press fuel tank cap to vent.
2. Move choke lever to cold start position (full choke).
3. Press primer bulb 5-10 times.
4. Place unit on ground, hold securely.
5. Pull starter rope briskly until engine fires (usually 1-3 pulls).
6. Immediately move choke lever to warm start/half-choke position.
7. Pull starter rope again to start engine.
8. Allow engine to warm up at idle for 30 seconds.

Operation: Squeeze throttle trigger lockout and throttle trigger to increase speed. Use a smooth, sweeping motion from right to left for trimming.

Fuel & Lubrication

Use fresh, unleaded gasoline with a minimum octane rating of 89. Mix with a high-quality 2-stroke engine oil designed for air-cooled engines at a 50:1 ratio (unless your specific oil specifies otherwise).

1. Fuel Mixture: Always mix fuel in a clean, approved fuel can. Never mix directly in the machine's tank.
2. Gearbox Lubrication: Lubricate the gearbox with STIHL gear oil (or equivalent) after every 25 hours of operation or as needed.
3. Storage: For storage over 30 days, drain all fuel from the tank and run the engine until it stops to prevent gumming in the carburetor.

Tip: STIHL MotoMix pre-mixed fuel is recommended to ensure optimal performance and reduce carburetor issues.

Cutting Attachments

Supports trimmer heads for nylon line and optional metal blades for brush clearing.

1. Standard Tap-and-Go Head: To advance line, tap the head firmly on the ground while the engine is running at high speed.
2. Line Replacement: Turn off engine. Remove spool, wind new line (max diameter 2.0 mm) as directed, and reassemble.
3. Metal Blade Installation: Use only STIHL-approved blades. Ensure the correct blade guard is installed. Tighten mounting nut securely with the provided wrench.
4. Inspection: Regularly check cutting attachment for wear, damage, or loose parts. Replace worn line or damaged blades immediately.

WARNING! Always stop the engine before inspecting, cleaning, or replacing the cutting attachment. Ensure the unit cannot accidentally start.

Maintenance & Storage

Regular maintenance ensures long life and safe operation.

Interval	Task
Before each use	Check for loose fasteners, fuel leaks, and damage. Inspect cutting attachment.
Every 25 hours	Clean air filter. Check spark plug. Lubricate gearbox.
Every 100 hours	Replace spark plug. Clean fuel filter (in tank). Check fuel lines.
Season end / Long storage	Drain fuel. Run engine dry. Clean entire unit. Store in dry place.

Cleaning: Use a brush or cloth. Keep cooling fins and air intake clear of debris.

Troubleshooting

Symptom	Possible Cause	Corrective Action
Engine will not start	No fuel, flooded, bad spark plug, choke position	Check fuel; wait if flooded; check/replace spark plug; ensure correct choke setting.
Engine starts but dies	Clogged air/fuel filter, carburetor adjustment	Clean/replace air filter; check fuel filter; may need carb adjustment by dealer.
Loss of power	Dirty air filter, old fuel, clogged spark arrestor	Clean air filter; use fresh fuel; clean spark arrestor screen.
Excessive vibration	Damaged cutting attachment, bent shaft, loose parts	Inspect and replace damaged cutter; check shaft; tighten all fasteners.
Line not advancing	Empty spool, line tangled, worn bump head	Refill spool; rewind line properly; replace tap-and-go mechanism if worn.

Service: For major repairs or carburetor adjustment, contact an authorized STIHL servicing dealer.

Warranty & Support

STIHL Limited Warranty: Covers defects in material and workmanship for a specified period from date of retail purchase. Proof of purchase required. Warranty does not cover damage from misuse, neglect, improper fuel, or unauthorized repairs. For the full warranty terms, see your STIHL warranty statement or dealer.

For technical support, parts, or to locate a dealer:

• Visit: www.stihlusa.com
• Customer Service: 1-800-467-8445

Always use genuine STIHL replacement parts to maintain performance, safety, and warranty coverage.