stihl hs 81 rc manual

The STIHL HS 81 RC is a professional-grade hedge trimmer designed for demanding trimming tasks. It features a powerful engine, a robust cutting blade, the STIHL Easy2Start™ system, an anti-vibration system, and the STIHL QuickStop® Plus inertia chain brake. Below are key sections for safety, features, operation, maintenance, and troubleshooting.

Features at a Glance

Key components: Powerful 2-stroke engine, Double-sided cutting blade with laser-cut teeth, STIHL Easy2Start™ system, Anti-vibration system, QuickStop® Plus inertia chain brake, Ergonomic handles.

Feature	Description
Engine	Powerful 2-stroke engine for professional use
Cutting Blade	Double-sided, 60 cm (24") length, laser-cut teeth
Starting System	STIHL Easy2Start™ for reduced pulling force
Vibration Damping	Anti-vibration system for reduced operator fatigue
Safety Feature	QuickStop® Plus inertia chain brake
Handle	Ergonomic rear handle with controls
Throttle Trigger	With throttle trigger lockout
Stop Switch	For immediate engine shutdown
Fuel Tank	Integrated, with fuel filter
Blade Guard	Protective cover for storage and transport

Safety Instructions

Read and understand all instructions before use. Wear appropriate PPE.

1. Personal Protective Equipment: Always wear safety glasses, hearing protection, gloves, sturdy boots, and close-fitting clothing.
2. Work Area Safety: Keep bystanders, children, and pets at a safe distance. Be aware of surroundings.
3. Tool Handling: Hold the tool firmly with both hands. Never operate with one hand.
4. Kickback Awareness: Be alert to potential kickback. Do not let the blade contact foreign objects.

WARNING! Risk of serious injury or death. Do not operate if tired, ill, or under the influence of drugs/alcohol. Always engage the chain brake when starting or carrying the tool.

Assembly & Preparation

Unpack and inspect contents. Assemble handle and attach blade guard.

1. Attach the Handle: Secure the rear handle to the engine housing using the provided screws and tool.
2. Fit the Blade Guard: Slide the protective blade guard onto the cutting blade before transport or storage.
3. Fuel Mixing: Use only STIHL 2-stroke engine oil mixed with unleaded gasoline (50:1 ratio). Shake well.
4. Fill Fuel Tank: Add the correct fuel/oil mixture to the fuel tank. Avoid spilling.
5. Fill Bar & Chain Oil: Fill the separate oil tank with STIHL chain oil for lubrication.

CAUTION! Fuel is highly flammable. Mix and refuel outdoors, away from sparks or flames. Wipe up any spills immediately.

Specifications

• Engine Power: High-performance 2-stroke engine.
• Cutting Length: 60 cm (24 inches).
• Tooth Spacing: 20 mm.
• Weight (powerhead): Approximately 5.8 kg (12.8 lbs).
• Fuel/Oil Ratio: 50:1 (STIHL 2-Stroke Oil).
• Fuel Tank Volume: 0.55 liters.
• Oil Tank Volume: 0.26 liters.
• Sound Power Level: Complies with relevant directives.
• Vibration Levels: Front/Rear handle values as per test standards.

Controls and Operation

Familiarize yourself with all controls before starting.

Controls: Stop Switch, Throttle Trigger with lockout, Throttle latch (for starting), Master Control Lever (for starting/choke), Chain Brake lever.

1. Starting (Cold Engine): Engage chain brake. Set Master Control lever to choke position. Press decompression valve (if equipped). Pull starter rope until engine fires. Move Master Control to half-throttle position. Pull starter rope to start. Briefly blip throttle to disengage starting throttle.
2. Starting (Warm Engine): Set Master Control lever to run position. Pull starter rope.
3. Operation: Disengage chain brake by pulling lever toward front handle. Squeeze throttle trigger to accelerate blade. Use smooth, sweeping motions. Do not force the tool.
4. Stopping: Release throttle trigger. Allow engine to idle. Press the stop switch to "0".

Fuel & Lubrication

Use only high-quality, fresh fuel and recommended oils.

1. Fuel: Unleaded gasoline with a minimum octane rating of 89 (RON). Mix with STIHL 2-Stroke Oil at 50:1.
2. Chain Oil: Use STIHL chain oil or a biodegradable alternative with good adhesion properties.
3. Refueling: Stop engine and allow to cool. Clean area around caps. Refill both fuel and oil tanks.

Tip: Never use fuel older than 30 days. Stale fuel is a common cause of starting and performance problems.

Maintenance & Cleaning

Regular maintenance ensures safety, performance, and longevity.

1. Air Filter: Clean regularly. Replace if damaged or excessively dirty.
2. Spark Plug: Check and clean electrode. Adjust gap to 0.5 mm. Replace if worn.
3. Fuel Filter: Replace annually or if clogged.
4. Exhaust Port & Spark Arrestor Screen: Clean carbon deposits to prevent overheating.
5. External Cleaning: Wipe down with a clean cloth. Keep cooling fins and air intakes clear.

WARNING! Always disconnect the spark plug boot before performing any maintenance.

Cutting Blade Care

A sharp, well-lubricated blade is essential for performance and safety.

1. Sharpening: Use a round file of the correct diameter. Maintain original tooth angles. Sharpen both sides equally.
2. Lubrication: The oil tank automatically lubricates the blade. Check oil flow before each use.
3. Inspection: Check for cracked, bent, or damaged teeth. Replace damaged blades immediately.
4. Tightening: Check blade mounting bolts periodically for tightness.

Storage

Prepare the tool properly for short or long-term storage.

1. Clean the tool thoroughly.
2. Drain the fuel tank and run the engine until it stops to clear the carburetor.
3. Remove the spark plug, add a few drops of engine oil into the cylinder, pull starter rope slowly, then reinstall plug.
4. Store in a dry, secure place, out of reach of children, with the blade guard installed.

CAUTION! Storing with fuel in the tank can lead to gumming of the carburetor. Always use the fuel drain screw or run the tank dry.

Regulatory Information

This product complies with relevant EU directives and standards for safety and environmental protection. The CE mark confirms conformity. Sound and vibration values are measured according to EN ISO 22868 and EN ISO 22867. Dispose of the product, batteries, and oils at the end of their life in accordance with local regulations. For genuine spare parts and service, contact your STIHL servicing dealer.

Troubleshooting

Symptom	Possible Cause	Corrective Action
Engine will not start	No fuel, flooded engine, dirty air filter, faulty spark plug	Check fuel; set choke to off and pull starter with throttle open; clean/replace filter; check/replace spark plug.
Engine runs poorly or lacks power	Dirty air/fuel filter, clogged spark arrestor, carburetor adjustment	Clean/replace filters; clean spark arrestor screen; have dealer adjust carburetor.
Excessive vibration	Loose parts, damaged blade, engine misfire	Tighten all bolts and nuts; inspect blade for damage; check engine condition.
Blade does not oil	Empty oil tank, clogged oil channel	Fill oil tank; clean oil output hole on guide bar; check oil pump.
Chain brake does not engage	Worn or dirty brake band, damaged mechanism	Clean brake components; have servicing dealer inspect and replace parts if necessary.

Service: For repairs beyond basic maintenance, contact your authorized STIHL servicing dealer. Use only genuine STIHL replacement parts.