STIHL Gas Trimmer Manual

The STIHL Gas Trimmer is a professional-grade, two-stroke engine powered trimmer designed for efficient grass and weed cutting. It features a lightweight yet durable construction, anti-vibration system, easy-start technology, adjustable handle, and a high-performance cutting head. Below are key sections for safety, features, assembly, operation, maintenance, and troubleshooting.

Features at a Glance

Key components: Two-stroke engine, Anti-vibration system, Easy-start technology, Adjustable handle, Quick-stop inertia chain brake, High-performance cutting head, Fuel tank, Throttle trigger, Stop switch.

Feature	Description
Two-stroke engine	High power-to-weight ratio for efficient cutting
Anti-vibration system	Reduces operator fatigue during extended use
Easy-start technology	Simplifies starting with reduced pull force
Adjustable handle	Customizable for operator comfort and control
Quick-stop inertia chain brake	Enhances safety by stopping cutting head rapidly
High-performance cutting head	Durable trimmer line for efficient grass and weed cutting
Fuel tank	Integrated tank for gasoline/oil mixture
Throttle trigger	Variable speed control for cutting power
Stop switch	Immediately stops engine when engaged

Safety Information

Read all instructions before operation. Wear appropriate safety gear.

1. Personal Protective Equipment: Always wear safety glasses, hearing protection, gloves, long pants, and sturdy boots.
2. Operating Area: Clear work area of bystanders, pets, and obstacles. Be aware of hidden objects like wires or rocks.
3. Fuel Safety: Mix fuel outdoors, away from sparks or flames. Store fuel in approved containers.
4. Hot Surfaces: Avoid contact with muffler and engine during and immediately after operation.

WARNING! Gas trimmers can cause serious injury. Never operate without proper training and safety gear. Keep hands and feet away from cutting head at all times.

Assembly Instructions

Unpack and inspect all parts. Assembly requires basic tools.

1. Attach handle: Align handle with shaft and secure with provided bolts.
2. Install cutting head: Follow instructions for specific trimmer model to attach cutting head securely.
3. Adjust handle position: Loosen adjustment knob, set handle to comfortable position, and retighten.
4. Add fuel mixture: Prepare correct gasoline/oil mix and fill tank (see Fuel section).

CAUTION! Ensure all fasteners are tightened securely before operation. Do not force parts during assembly.

Specifications

• Engine Type: Two-stroke, air-cooled.
• Displacement: Varies by model (e.g., 25.4 cc).
• Power Output: High torque for demanding cutting tasks.
• Fuel Tank Capacity: Approximately 14.9 fl oz (440 ml).
• Cutting Swath: Up to 17 inches (varies by head and line).
• Weight: Approximately 10.6 lbs (4.8 kg) without fuel.
• Sound Power Level: Typically 100 dB(A). Wear hearing protection.
• Vibration Level: Reduced by anti-vibration system.

Controls and Operation

Familiarize yourself with all controls before starting.

Main Controls: Throttle trigger (variable speed), Stop switch (emergency stop), Choke lever (cold starts), Primer bulb (fuel priming), Throttle lock (safety lock).

Operation: Hold trimmer firmly with both hands. Keep cutting head parallel to ground and use sweeping motions. Do not raise cutting head above waist level. Always be aware of kickback potential.

Fuel and Oil Mixing

Use fresh, unleaded gasoline (minimum 89 octane) and STIHL two-stroke engine oil.

1. Mix ratio: Typically 50:1 (2.6 fl oz oil per 1 gallon gasoline). Check manual for specific model.
2. Mixing container: Use approved fuel can. Add gasoline first, then oil. Shake thoroughly.
3. Storage: Use fuel within 30 days. Do not mix more than needed for immediate use.

Tip: Never use automotive oil or straight gasoline. Improper mix can cause engine damage.

Starting and Stopping

Follow proper starting procedure to avoid injury and damage.

1. Cold Start: Set stop switch to "I" (run). Set choke to full. Press primer bulb 5 times. Pull starter cord briskly until engine fires. Move choke to half position. Pull starter cord again to start. Warm up for 30 seconds.
2. Warm Start: Choke off. Press primer bulb once if needed. Pull starter cord.
3. Stopping: Release throttle trigger. Allow engine to idle briefly. Move stop switch to "0" (stop).

WARNING! Keep firm footing when pulling starter cord. Never drop-start or throw starter cord.

Cutting Techniques

Proper technique ensures efficiency and safety.

1. Basic Trimming: Hold cutting head parallel to ground, about 2 inches above soil. Use sweeping side-to-side motion.
2. Edging: Tilt trimmer to cut vertical edges along sidewalks or driveways.
3. Tall Weeds: Use tip of line for cutting. Avoid forcing trimmer through dense growth.
4. Line Advancement: Tap cutting head on ground (while running at high speed) to advance fresh line.

CAUTION! Never use metal blades or attachments not approved by STIHL. Avoid cutting near fences, buildings, or hard surfaces that could damage line or cause kickback.

Maintenance & Cleaning

Regular maintenance ensures optimal performance and longevity.

After each use: Clean exterior with dry cloth. Check for loose fasteners. Inspect cutting head for wear.

Weekly: Clean air filter. Check spark plug. Inspect fuel lines for cracks.

Monthly: Clean cooling fins. Check anti-vibration elements. Lubricate drive shaft (if applicable).

CAUTION! Always disconnect spark plug wire before performing maintenance. Allow engine to cool completely.

Storage Guidelines

Proper storage prevents fuel system issues and corrosion.

1. Short-term (under 30 days): Store in dry location with fuel tank full.
2. Long-term: Drain fuel tank completely. Run engine until it stops to clear carburetor. Remove spark plug and add teaspoon of oil to cylinder. Pull starter cord slowly to distribute oil. Reinstall spark plug. Store in dry, covered area.

WARNING! Never store trimmer with fuel in tank in enclosed spaces or near heat sources.

Troubleshooting

Symptom	Possible Cause	Corrective Action
Engine won't start	Old fuel, clogged filter, spark plug	Use fresh fuel mix; clean/replace air filter; check/replace spark plug.
Engine runs poorly	Dirty carburetor, fuel line issue	Clean carburetor; inspect fuel lines for cracks or blockages.
Excessive vibration	Loose components, bent shaft	Tighten all fasteners; inspect shaft for damage.
Line not advancing	Worn head, tangled line	Replace cutting head or spool; reload line correctly.
Loss of power	Clogged exhaust, compression loss	Clean spark arrestor screen; check cylinder and piston.

Service: For repairs beyond basic maintenance, contact authorized STIHL servicing dealer.

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