stihl sg 20 manual

The STIHL SG 20 is a professional-grade battery-powered grass trimmer designed for efficient and quiet lawn maintenance. It features a brushless motor, an adjustable cutting head, a lightweight yet durable construction, and compatibility with the STIHL AK System battery platform. Below are key sections for safety, features, assembly, operation, maintenance, and troubleshooting.

Features at a Glance

Key components: Brushless electric motor, Adjustable cutting head, AK battery interface, Lightweight shaft, Ergonomic handle with controls, Safety guard.

Feature	Description
Power Source	STIHL AK Series battery (e.g., AK 20, AK 30)
Motor Type	Brushless, efficient, low maintenance
Cutting Width	Adjustable, up to 20 cm (approx. 8 inches)
Cutting Line	Automatic feed system (AFS)
Weight (without battery)	Approx. 2.5 kg (5.5 lbs)
Handle	D-loop handle with ergonomic grip
Noise Level	Low, suitable for residential areas
Safety Features	Two-hand operation, safety guard, instant stop

Safety Information

Read all instructions before use. Wear appropriate personal protective equipment (PPE).

1. Always wear safety glasses, hearing protection, long pants, and sturdy shoes.
2. Inspect the trimmer and cutting head before each use for damage or wear.
3. Ensure the work area is clear of people, pets, and obstacles.
4. Operate with both hands on the handles at all times.
5. Do not operate in wet conditions or rain.

WARNING! The cutting line rotates at high speed and can cause serious injury. Keep hands and feet away from the cutting head during operation. Never operate without the safety guard properly installed.

Assembly & First Use

Unpack all components. Assembly requires minimal tools.

1. Attach the handle: Slide onto shaft and tighten clamp screws securely.
2. Install the safety guard: Align and secure with provided screws.
3. Install the battery: Insert a compatible STIHL AK battery until it clicks.
4. Load the cutting line: Follow instructions on spool housing; ensure line is wound correctly and feeds freely.
5. Perform a function test: Press safety lock and throttle trigger to ensure motor runs and stops correctly.

CAUTION! Ensure all fasteners are tight before operation. Do not force components during assembly.

Specifications

• Model: STIHL SG 20
• Type: Battery-powered grass trimmer/brushcutter
• Motor: Brushless electric motor
• Battery System: STIHL AK Series (recommended AK 20 or higher)
• Cutting Width: Adjustable, max 20 cm (8 in)
• Line Diameter: 2.0 mm (0.08 in) standard
• Sound Pressure Level: < 85 dB(A)
• Vibration Level: < 2.5 m/s²
• Weight (excl. battery): Approx. 2.5 kg (5.5 lbs)

Controls and Operation

Handle contains main controls. Operation requires two-hand engagement.

Controls: On/Off switch, Safety lock lever, Throttle trigger, Battery charge indicator.

Starting: Press and hold safety lock lever, then squeeze throttle trigger. Release throttle to stop.

Operating Technique: Hold trimmer at a slight angle, sweeping from side to side. Keep cutting head parallel to ground for even cutting. Avoid forcing the tool; let the line speed do the work.

Line Feed: Tap head lightly on ground while running at full speed to advance fresh line (Automatic Feed System - AFS).

Cutting Head Adjustment

The cutting head angle can be adjusted for different trimming positions.

1. Stop motor and remove battery.
2. Loosen the adjustment knob on the head housing.
3. Rotate head to desired angle (multiple positions available).
4. Tighten knob securely.
5. Reinstall battery and test operation.

Tip: Adjust head for edging by rotating 90 degrees. Ensure knob is tight to prevent movement during use.

Battery & Charging

Use only STIHL AK Series batteries and approved chargers.

1. Charging: Insert battery into charger; connect to proper power outlet. LED indicates charging status.
2. Battery Care: Store batteries in a cool, dry place. Avoid complete discharge for long-term storage.
3. Run Time: Varies by battery capacity (AK 20: approx. 20-30 mins; AK 30: approx. 40-60 mins under typical load).
4. Battery Indicator: Check level via button on battery or on-tool indicator.

WARNING! Use only STIHL original batteries and chargers. Do not expose batteries to fire, water, or extreme temperatures. Do not disassemble.

Maintenance & Storage

Regular maintenance ensures optimal performance and longevity.

• After each use: Clean housing and guard with a dry cloth. Inspect for damage.
• Weekly: Check cutting head for wear, replace line spool as needed.
• Monthly: Inspect shaft and handle for loose fasteners; tighten if necessary.
• Storage: Remove battery. Store in a dry, dust-free location, out of reach of children.

CAUTION! Always remove battery before performing any maintenance. Do not use water or solvents for cleaning.

Troubleshooting

Symptom	Possible Cause	Corrective Action
Motor does not start	Battery empty/not connected	Charge battery; ensure it's fully inserted and clicks.
Line does not feed	Spool empty/jammed	Refill or replace spool; ensure line is wound correctly.
Reduced run time	Old battery/heavy load	Check battery health; avoid cutting thick weeds continuously.
Excessive vibration	Damaged cutting head/bent shaft	Inspect head and shaft; replace damaged parts.
Tool stops during use	Overload/overheating	Release trigger; allow motor to cool; reduce cutting load.

Reset: Remove battery for 60 seconds to reset electronics if tool behaves unexpectedly.

Warranty & Support

STIHL limited warranty applies. Register your product for full warranty benefits. For technical support, genuine parts, and service, contact an authorized STIHL dealer.

Support: Visit www.stihl.com for dealer locator, manuals, and FAQs. Contact your local STIHL dealer for service inquiries.

Disposal: Dispose of the product, battery, and packaging according to local environmental regulations. Do not dispose with household waste.