Stihl BG72 Leaf Blower Manual

The Stihl BG72 is a professional-grade backpack leaf blower designed for demanding commercial and residential use. It features a powerful 2-stroke engine, comfortable backpack harness, variable speed control, 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 9. Troubleshooting 10. Warranty Information

Features at a Glance

Key components: Powerful 2-stroke engine, Backpack harness system, Throttle trigger with lock, Air volume control, Blower tube with adjustable nozzle, Fuel tank, Primer bulb, Spark plug, and Air filter.

Feature	Description
Engine Type	2-stroke, single cylinder, air-cooled
Displacement	28.4 cc (1.73 cu. in.)
Power Output	1.1 kW (1.5 hp)
Fuel Tank Capacity	1.0 L (33.8 fl. oz.)
Air Volume	Up to 650 m³/h (383 cfm)
Air Speed	Up to 75 m/s (168 mph)
Sound Pressure Level	Typically 112 dB(A)
Weight (dry)	Approx. 8.5 kg (18.7 lbs)
Harness System	Padded backpack with adjustable straps
Throttle Control	Variable speed with lock-on function

Safety Information

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

Always wear hearing protection, eye protection, and sturdy gloves.
Operate in well-ventilated areas only; exhaust contains carbon monoxide.
Keep bystanders, pets, and children at least 15 meters away.
Inspect unit before each use for damage or loose parts.
Use only STIHL-approved fuel mixture (50:1 gasoline to 2-stroke oil).

WARNING! Risk of fire and explosion. Do not operate near flammable materials or in enclosed spaces. Never refuel while engine is hot or running.

Assembly & Preparation

Unpack and inspect all parts. Assemble according to diagram.

Attach harness: Connect backpack frame to blower unit with supplied bolts.
Install blower tube: Push tube onto engine outlet until it clicks securely.
Attach nozzle: Select appropriate nozzle (round or flat) and secure to tube.
Adjust harness: Put on backpack, adjust shoulder and waist straps for comfort and balance.
Fuel mixture: Prepare 50:1 mix with 89+ octane gasoline and STIHL HP Ultra oil.

CAUTION! Ensure all fasteners are tight before operation. Do not force connections.

Specifications

Model: BG72 Professional Backpack Blower.
Engine: STIHL 2-MIX engine technology for reduced emissions.
Ignition System: Electronic, capacitor discharge.
Carburetor: Diaphragm type with adjustable high-speed jet.
Starting System: Rewind starter with decompression valve.
Vibration Damping: Anti-vibration system in handles and harness.
Warranty: Limited commercial warranty (see section 11).
Compliance: Meets EPA Phase III and CARB regulations.

Controls and Operation

Master Control Lever: Combines stop switch, choke, and run positions. Throttle Trigger: Variable speed control with lock button. Air Volume Control: Dial on side of unit to adjust airflow.

Starting Procedure:

Place unit on flat, clear ground.
Set Master Control to choke position (cold start).
Press primer bulb 5-10 times until fuel is visible.
Pull starter rope briskly until engine fires.
Move Master Control to run position.
Squeeze throttle trigger to operate.

Operating Tips: Use sweeping motions. Adjust air volume for material type. Avoid pointing nozzle at people, animals, or debris that could become projectiles.

Fuel & Lubrication

Use only fresh, unleaded gasoline with minimum 89 octane. Mix with STIHL HP Ultra 2-stroke oil at 50:1 ratio.

Clean area around fuel cap before opening.
Pour correct amount of oil into approved fuel container.
Add gasoline, close container, and shake thoroughly.
Fill fuel tank to 80% capacity to allow for expansion.
Wipe any spilled fuel immediately.

Tip: Use fuel within 30 days. Add fuel stabilizer if storing longer than 30 days.

Maintenance Schedule

Regular maintenance ensures optimal performance and longevity.

Interval	Task
Before each use	Check for loose fasteners, inspect air filter, test throttle operation
Every 10 hours	Clean air filter, check spark plug condition
Every 25 hours	Clean spark arrestor screen, inspect fuel filter
Every 50 hours	Replace air filter, check carburetor adjustment
Every 100 hours	Replace spark plug, clean combustion chamber
Annually	Inspect all hoses and connections, replace fuel lines if cracked

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

Storage

Proper storage prevents fuel system issues and corrosion.

Drain fuel tank completely or add fuel stabilizer.
Run engine until it stops to clear carburetor.
Remove spark plug and add 1 teaspoon of oil through spark plug hole.
Pull starter rope slowly to distribute oil, then reinstall plug.
Clean entire unit, especially cooling fins and air intake.
Store in dry, well-ventilated area, protected from moisture.

CAUTION! Never store with fuel in tank for more than 30 days without stabilizer.

Troubleshooting

Symptom	Possible Cause	Corrective Action
Engine won't start	Old fuel, clogged filter, no spark	Use fresh fuel mix, clean/replace air filter, check spark plug gap (0.5 mm).
Engine starts then dies	Clogged fuel filter, carburetor issue	Replace fuel filter, clean carburetor jets, check fuel line.
Loss of power	Dirty air filter, clogged spark arrestor	Clean air filter, remove and clean spark arrestor screen.
Excessive vibration	Loose components, bent impeller	Tighten all fasteners, inspect impeller for damage.
Unusual noise	Worn bearings, foreign object in impeller	Inspect impeller housing, check bearings for wear.

Reset: For electronic issues, disconnect spark plug wire for 30 seconds.

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

Warranty Information

STIHL BG72 comes with a limited warranty. Commercial use: 90-day warranty from date of purchase. Residential use: 1-year warranty. Warranty covers defects in materials and workmanship. Not covered: Normal wear, misuse, improper maintenance, or use of non-STIHL parts. Proof of purchase required. For warranty claims, contact authorized STIHL dealer or STIHL Incorporated at 1-800-467-8445 or visit www.stihlusa.com.