STIHL Trimmer Owners Manual

The STIHL Trimmer is a professional-grade power tool designed for efficient grass trimming, brush clearing, and edge maintenance. This manual covers safety instructions, assembly, operation, maintenance, troubleshooting, and specifications for your STIHL trimmer model. Always read and understand this manual before using the equipment to ensure safe and proper operation.

1. Safety Instructions 2. Assembly & Preparation 3. Controls & Features 4. Operation Guidelines 5. Maintenance Schedule 6. Cutting Attachments 7. Fuel & Lubrication 8. Storage Guidelines 9. Troubleshooting 10. Specifications 11. Warranty & Support

Safety Instructions

Always wear proper personal protective equipment (PPE) including safety glasses, hearing protection, gloves, long pants, and sturdy boots. Keep bystanders and pets at a safe distance.

Hazard	Precaution
Kickback	Keep cutting attachment below waist level; maintain firm grip
Flying debris	Clear work area of stones, wire, and other objects
Fuel handling	Refuel outdoors only when engine is cool
Carbon monoxide	Never operate in enclosed or poorly ventilated areas
Hot surfaces	Avoid contact with muffler and engine during/after operation
Vibration	Take regular breaks to reduce fatigue
Electrical hazards	Keep away from power lines and electrical sources
Starting safety	Ensure trimmer head is clear of ground and obstacles
Transport	Engage chain brake (if equipped); carry with cutting attachment rearward
Children	Never allow children to operate or be near running equipment

Assembly & Preparation

Unpack all components and inspect for damage. Follow assembly steps in order.

Handle Assembly: Attitch handle to shaft using provided bolts; tighten securely.
Cutting Attachment: Install trimmer head or blade according to model specifications.
Fuel Mix: Prepare proper gasoline/oil mixture (typically 50:1 for 2-stroke engines).
Shoulder Strap: Adjust strap for comfortable, balanced operation.
Starting Position: Place trimmer on clear, level ground for starting.

WARNING! Never attempt assembly with engine running. Ensure all fasteners are tight before operation.

Controls & Features

Familiarize yourself with all controls before starting the engine.

Throttle Trigger: Controls engine speed; release to idle.
Throttle Trigger Lockout: Must be depressed before throttle can be engaged.
Stop Switch: Turns ignition off; move to "0" or "STOP" position.
Choke Control: Used for cold starting; move to choke position.
Purge Bulb: Press several times to prime fuel system (if equipped).
Decompression Valve: Reduces starting effort (on some models).
Handle Controls: Includes vibration-dampening system and adjustable handle positions.
Cutting Attachment Guard: Protects operator from debris; never operate without guard.

CAUTION! Know location and function of all controls. Practice starting and stopping before actual use.

Operation Guidelines

Starting Procedure: Set stop switch to "I", engage choke, press purge bulb, set on ground, pull starter cord briskly.
Warm-up: Allow engine to warm at idle for 30-60 seconds before applying load.
Cutting Technique: Swing trimmer in arc from right to left; cut with tip of line for best efficiency.
Slope Operation: Always stand across slope, not up or down; maintain secure footing.
Line Advancement: Tap trimmer head on ground at full throttle to advance cutting line (bump-feed models).
Shut Down: Release throttle, allow to idle 30 seconds, move stop switch to "0".
Carrying: Always carry with cutting attachment pointing away from body.

Maintenance Schedule

Regular maintenance ensures optimal performance and longevity.

Interval	Task	Procedure
Before each use	Inspection	Check for loose fasteners, damage, proper guard installation
Daily	Air filter	Clean or replace as needed; more often in dusty conditions
25 hours	Spark plug	Clean, check gap, replace if worn (typically 0.020")
50 hours	Fuel filter	Replace fuel filter in tank
100 hours	Carburetor	Inspect and clean; professional service recommended
Seasonal	Shaft lubrication	Grease drive shaft bearings (if equipped)
As needed	Cutting attachment	Replace worn line, sharpen blades, check balance

Cutting Attachments

Various attachments available for different applications.

Trimmer Head: Uses nylon line for grass and light weeds; line diameters from 0.080" to 0.155".
Circular Blades: Metal blades for heavy brush and saplings; available in 3-tooth to 80-tooth configurations.
Brush Knife: For medium brush; typically 4-8 teeth.
Clearing Blades: For very heavy vegetation; use with extreme caution.
Installation: Always disconnect spark plug before changing attachments.
Sharpening: Keep blades sharp; dull blades reduce efficiency and increase vibration.

WARNING! Always use STIHL-approved attachments. Never use metal blades for edging or near hard surfaces.

Fuel & Lubrication

Proper fuel mixture is critical for 2-stroke engine operation.

Fuel Type: Use fresh unleaded gasoline with minimum 89 octane (R+M)/2.
Oil: STIHL 2-stroke engine oil or equivalent meeting ISO-L-EGD standards.
Mix Ratio: Typically 50:1 (2.6 oz oil per gallon) for most STIHL trimmers.
Mixing: Add oil to gasoline in approved container; shake thoroughly.
Storage: Use fuel within 30 days; add fuel stabilizer for longer storage.
Gearbox Lubrication: Use STIHL gear oil; check level monthly.
Bar & Chain Oil: For brushcutter attachments; use proper viscosity for conditions.

CAUTION! Never use automotive oil or fuel with more than 10% ethanol. Never use straight gasoline.

Storage Guidelines

Proper storage prevents fuel system issues and corrosion.

Run carburetor dry: Let engine run until it stops from fuel exhaustion.
Clean thoroughly: Remove grass, dirt, and debris from entire unit.
Inspect: Check for wear or damage; address before next season.
Fuel tank: Either empty completely or fill completely with stabilized fuel.
Remove battery: For electric start models, remove and store battery separately.
Store properly: Keep in dry, secure location away from children.
Cover: Use breathable cover to prevent dust accumulation.

Tip: Consider professional end-of-season service for optimal spring startup.

Troubleshooting

Symptom	Possible Cause	Corrective Action
Engine won't start	Old fuel, clogged filter, flooded	Use fresh fuel mix, clean filter, wait 10 minutes if flooded
Engine starts then dies	Dirty carburetor, fuel line issue	Clean carburetor, check fuel lines for cracks
Poor performance	Dirty air filter, spark plug	Clean/replace air filter, check/replace spark plug
Excessive vibration	Unbalanced blade, bent shaft	Balance blade, inspect shaft for damage
Line won't advance	Empty spool, tangled line	Refill spool, untangle or replace line
Overheating	Dirty cooling fins, lean mixture	Clean cooling fins, check carburetor adjustment
Hard starting when warm	Faulty ignition coil	Check spark; replace coil if weak or inconsistent

Reset: For electronic ignition models, disconnect spark plug for 5 minutes to reset system.

Specifications

Engine Type: 2-stroke, single cylinder, air-cooled
Displacement: 25.4 cc to 40.2 cc (varies by model)
Power Output: 1.0 HP to 2.4 HP
Fuel Capacity: 14.9 fl oz to 26.9 fl oz
Weight: 10.6 lbs to 14.3 lbs (without cutting attachment)
Shaft Type: Straight or curved; solid or flexible drive
Sound Pressure: 94 dB(A) to 106 dB(A) at operator's ear
Vibration Levels: Front handle: 2.5 m/s² to 6.5 m/s²; Rear handle: 1.5 m/s² to 4.5 m/s²
Warranty: Limited warranty: 1 year consumer, 90 days commercial

Warranty & Support

STIHL offers limited warranties through authorized dealers. Register your product online for full warranty benefits.

Consumer Warranty: 1 year from date of purchase for residential use.
Commercial Warranty: 90 days from date of purchase for commercial use.
Emission Warranty: 2 years or 150 hours for emissions-related components.
Support: Contact authorized STIHL dealer for service and genuine parts.
Manual Updates: Check www.stihlusa.com for latest manual revisions.
Safety Training: Many dealers offer free operator training sessions.

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