STIHL BG85 Blower Manual

The STIHL BG85 is a professional-grade handheld backpack blower designed for demanding cleanup tasks. It features a powerful 2-stroke engine, comfortable harness system, variable speed throttle, and a range of nozzles for different applications. Below are key sections for safety, features, operation, maintenance, troubleshooting, and specifications.

1. Features at a Glance 2. Safety Information 3. Assembly & Preparation 4. Specifications 5. Controls and Operation 6. Fuel & Lubrication 7. Maintenance Schedule 8. Storage Guidelines 10. Troubleshooting

Features at a Glance

Key components: Powerful 2-stroke engine, Comfortable backpack harness, Variable speed throttle, Tube lock for secure connection, Air volume control, and multiple nozzle options.

Feature	Description
Engine Type	STIHL 2-MIX 2-stroke engine
Displacement	64.8 cm³ (3.95 cu. in.)
Power Output	2.2 kW (3.0 hp)
Maximum Air Speed	Approx. 320 km/h (199 mph)
Maximum Air Volume	Approx. 1,100 m³/h (647 cfm)
Fuel Tank Capacity	1.0 L (33.8 fl. oz.)
Sound Power Level	112 dB(A)
Weight (without fuel)	9.5 kg (20.9 lbs)
Harness System	Padded backpack harness with quick-release buckles
Throttle Control	Variable speed with lock-on function

Safety Information

Read and understand all instructions before operating. Wear appropriate personal protective equipment (PPE).

Personal Protective Equipment: Always wear eye protection, hearing protection, long pants, sturdy gloves, and non-slip footwear.
Operating Area: Keep bystanders, especially children and pets, at least 15 meters (50 feet) away. Be aware of your surroundings.
Fuel Safety: Fuel only in a well-ventilated area, with the engine stopped and cool. Use only STIHL MotoMix® or a 50:1 gasoline/oil mixture with STIHL 2-stroke oil. Never smoke near fuel.
Starting & Operation: Start the blower on the ground in a clear area. Never carry the blower while starting. Keep a firm grip with both hands during operation.
Hot Surfaces: The muffler and engine become extremely hot during and after use. Allow to cool before touching or storing.

WARNING! Failure to follow safety instructions can result in serious injury or death. The blower can propel objects at high speed. Always direct the airflow away from people, animals, windows, and vehicles.

Assembly & Preparation

Unpack and inspect all parts. Assemble on a clean, flat surface.

Attach the Tube: Align the tube with the blower housing outlet. Push firmly until it clicks into place. Engage the tube lock lever to secure.
Attach the Nozzle: Slide the desired nozzle (round or flat) onto the end of the tube and tighten the clamping screw.
Install the Harness: Put on the backpack frame. Connect the shoulder straps and waist belt, adjusting for a snug, comfortable fit that places the blower unit high on your back.
Connect to Harness: Hook the blower unit onto the harness frame. Ensure all quick-release buckles are securely fastened.
Fueling: Clean the area around the fuel cap. Add the correct fuel/oil mixture to the fuel tank. Replace the cap and tighten securely. Wipe up any spills immediately.

CAUTION! Ensure all connections are secure before starting the engine. Do not operate with loose parts.

Specifications

Model: STIHL BG 85
Engine: STIHL 2-MIX single-cylinder 2-stroke
Displacement: 64.8 cm³
Power Output: 2.2 kW / 3.0 hp
Idle Speed: 2,800 rpm
Maximum Air Speed: 320 km/h (199 mph)
Maximum Air Volume: 1,100 m³/h (647 cfm)
Fuel/Oil Ratio: 50:1 (with STIHL 2-stroke oil)
Fuel Tank Capacity: 1.0 liter
Sound Power Level (LWA): 112 dB(A)
Vibration Levels (ah, K): Left: 4.0 m/s², Right: 4.0 m/s²
Weight (without fuel): 9.5 kg (20.9 lbs)
Warranty: Refer to your STIHL warranty statement.

Controls and Operation

Familiarize yourself with all controls before starting.

Main Controls: - Master Control Lever (STOP/START): Controls ignition and choke. Positions: STOP (0), START (warm start), CHOKE (cold start). - Throttle Trigger: Variable speed control. Squeeze to increase engine speed. - Throttle Trigger Lock: Locks the throttle in a mid-range position for starting. - Air Volume Control Slider: Located on the blower housing. Adjusts the balance between air speed and volume. - Tube Lock Lever: Secures the tube to the blower housing.

Starting Procedure (Cold Engine): 1. Press the fuel pump bulb at least 5 times. 2. Set the Master Control lever to CHOKE (full left). 3. Lock the throttle trigger by pressing the lock button and squeezing the trigger, then release the trigger. 4. Place the blower unit firmly on the ground. Hold it down with your foot through the rear handle. 5. Pull the starter rope briskly until the engine fires (usually 2-5 pulls). 6. Immediately move the Master Control lever to the START (half-throttle) position. 7. Pull the starter rope again to start the engine. 8. Allow the engine to warm up for 30-60 seconds before applying full throttle.

Stopping: Move the Master Control lever to STOP (0).

Fuel & Lubrication

Fuel Mixture: Use only high-quality unleaded gasoline with a minimum octane rating of 89 (RON). Mix with STIHL 2-stroke engine oil at a 50:1 ratio. For ultimate convenience and engine protection, use STIHL MotoMix® premixed fuel (50:1).

Mixing Instructions: 1. Use a clean, approved fuel can. 2. Add half the gasoline. 3. Add the entire amount of STIHL 2-stroke oil. 4. Close the can and shake vigorously. 5. Add the remaining gasoline and shake again.

Lubrication: The engine is lubricated by the oil in the fuel mixture. The gearbox is filled with grease at the factory and requires no routine lubrication under normal use.

WARNING! Gasoline is extremely flammable. Store fuel in a cool, well-ventilated place away from sparks, flames, or heat sources. Never store fuel or a fueled machine indoors.

Maintenance Schedule

Interval	Task
Before each use	Check for loose fasteners, damage, and fuel leaks. Clean air intake and exterior.
Daily	Clean the blower tube and nozzle of debris. Check the spark plug boot is secure.
Every 3 months or 50 hours	Clean or replace the air filter. Check the spark plug condition and gap.
Every 6 months or 100 hours	Clean the cooling fins and exhaust area. Check fuel filter and fuel lines.
Annually or 300 hours	Have the carburetor adjusted and engine compression checked by an authorized STIHL servicing dealer.

Air Filter Service: A dirty air filter reduces power and can damage the engine. Clean the foam filter in warm, soapy water, rinse, dry, and re-oil with STIHL air filter oil.

Storage Guidelines

Short-Term (less than 30 days): Store in a dry, secure location out of reach of children.

Long-Term (more than 30 days): 1. Fuel System: Run the engine until it stops from fuel starvation to empty the carburetor. This prevents gum deposits. 2. Cleaning: Thoroughly clean the entire blower, especially the cooling fins and air intake. 3. Spark Plug: Remove the spark plug, pour a teaspoon of 2-stroke oil into the cylinder, pull the starter rope slowly 2-3 times to coat internal parts, and reinstall the plug. 4. Storage: Store in a dry, dust-free, and well-ventilated area, preferably covered.

CAUTION! Never store the blower with fuel in the tank indoors or in an enclosed space due to fire and fume hazards.

Troubleshooting

Symptom	Possible Cause	Corrective Action
Engine will not start	1. Master Control in STOP. 2. No fuel. 3. Flooded engine. 4. Dirty air filter. 5. Faulty spark plug.	1. Move to START/CHOKE. 2. Refuel. 3. Move lever to START, hold throttle wide open, pull starter 10+ times. 4. Clean/replace air filter. 5. Clean, gap, or replace spark plug.
Engine starts but dies	1. Choke still on. 2. Dirty fuel filter. 3. Carburetor adjustment.	1. Move Master Control to START. 2. Replace fuel filter. 3. See authorized STIHL dealer.
Loss of power	1. Dirty air filter. 2. Clogged fuel filter. 3. Clogged spark arrestor screen.	1. Clean air filter. 2. Replace fuel filter. 3. Clean spark arrestor screen (dealer service).
Excessive vibration	1. Loose parts. 2. Damaged impeller/fan.	1. Tighten all fasteners. 2. Stop use immediately and contact dealer.
Airflow seems weak	1. Tube not fully connected. 2. Debris in tube/nozzle. 3. Worn impeller.	1. Check tube lock. 2. Clean tube and nozzle. 3. Contact dealer for inspection.

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