Operating Manual for Stihl Magnum Back Pack Blower

The Stihl Magnum Back Pack Blower is a professional-grade, high-performance blower designed for demanding landscaping and debris clearing tasks. It features a powerful 2-stroke engine, ergonomic backpack harness, variable speed throttle, anti-vibration system, and multiple nozzle attachments. Below are key sections for safety, features, assembly, operation, maintenance, and troubleshooting.

Features at a Glance

Key components: High-torque 2-stroke engine, Backpack harness with padded straps, Telescopic blower tube, Variable speed throttle control, Air volume control lever, Fuel tank with quick-fill cap, Spark arrestor muffler.

Assembly & Setup

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

1. Attach harness: Connect backpack frame to harness straps; adjust for fit.
2. Install blower tube: Insert telescopic tube into engine housing; secure with locking collar.
3. Attach nozzle: Select desired nozzle (round/flat) and secure to tube end.
4. Fuel mixture: Prepare 50:1 gasoline to 2-stroke oil mixture; fill tank.
5. Check all fasteners: Ensure all screws and connections are tight.

WARNING! Always wear protective gloves during assembly. Ensure blower is on stable surface.

Safety Instructions

Read all instructions before operation. Always wear appropriate PPE.

1. Personal Protective Equipment: Wear safety glasses, hearing protection, gloves, long pants, and sturdy shoes.
2. Operating Area: Clear work area of bystanders, especially children and pets.
3. Fuel Safety: Refuel in well-ventilated area with engine off and cool. No smoking.
4. Starting Procedure: Place blower on ground; ensure tube is clear before starting.
5. Operating Position: Keep firm footing; do not overreach. Maintain balance at all times.

CAUTION! Never operate blower in enclosed spaces. Carbon monoxide poisoning hazard.

Specifications

• Engine Displacement: 79.2 cc (4.83 cu. in.)
• Power Output: 4.1 HP
• Maximum Air Velocity: 200 mph
• Maximum Air Volume: 885 CFM
• Fuel Capacity: 1.9 U.S. quarts (1.8 liters)
• Dry Weight: 24.7 lbs (11.2 kg)
• Sound Power Level: 112 dB(A)
• Vibration Levels: Front handle: 4.2 m/s²; Rear handle: 5.8 m/s²
• Warranty: Limited 2-year commercial warranty

Controls and Functions

Main controls located on handle and engine housing.

Handle Controls: Throttle trigger, Cruise control lock, Air volume adjustment lever, Harness quick-release buckle.

Engine Housing: ON/OFF switch, Choke lever, Primer bulb, Fuel tank cap, Recoil starter grip, Muffler guard.

Adjustments: Harness strap length, Telescopic tube length, Nozzle rotation, Air volume control.

Operating Instructions

Starting, operation, and shutdown procedures.

1. Pre-start check: Ensure harness is properly adjusted; clear area of debris.
2. Starting: Set switch to ON; set choke; press primer 5 times; pull starter cord firmly.
3. Warm-up: Allow engine to run at idle for 1-2 minutes before applying load.
4. Operation: Adjust air volume for task; use sweeping motions for best results.
5. Shutdown: Release throttle; allow engine to idle for 30 seconds; turn switch to OFF.
6. Transport: Always carry with tube pointing downward.

Tip: For heavy debris, use lower air volume with flat nozzle. For leaves, use high volume with round nozzle.

Maintenance & Cleaning

Regular maintenance ensures optimal performance and longevity.

1. Daily: Clean air filter; check for loose fasteners; inspect tube for obstructions.
2. Weekly: Clean spark arrestor screen; check fuel lines for cracks.
3. Monthly: Replace spark plug; clean cooling fins; check harness straps.
4. Seasonal: Replace fuel filter; clean carburetor; inspect anti-vibration mounts.
5. Storage: Run engine dry or add fuel stabilizer for long-term storage.

WARNING! Always disconnect spark plug wire before performing maintenance.

Storage Guidelines

Proper storage prevents fuel system issues and corrosion.

1. Short-term (under 30 days): Add fuel stabilizer; run engine for 5 minutes.
2. Long-term (over 30 days): Drain fuel tank and carburetor; run until engine stops.
3. Clean entire unit: Remove debris from cooling fins, tube, and housing.
4. Storage location: Cool, dry place away from direct sunlight and ignition sources.
5. Harness care: Hang harness separately to maintain shape.

CAUTION! Never store blower with fuel in tank for extended periods without stabilizer.

Warranty Information

Stihl Limited Warranty: 2-year commercial warranty from date of purchase. Warranty covers defects in materials and workmanship. Not covered: Normal wear, misuse, improper maintenance, unauthorized repairs. Keep original receipt as proof of purchase. For warranty service, contact authorized Stihl dealer.

Regulatory Compliance

EPA Phase 3 Certified: Meets emission standards for handheld engines. CARB Certified: Complies with California Air Resources Board requirements. USDA Approved: Spark arrestor meets Forest Service standards. ANSI B175.2: Complies with safety standards for handheld powered equipment. For emissions compliance information, visit www.stihlusa.com or contact 1-800-467-8445.

Troubleshooting

Service: For repairs, contact authorized Stihl dealer only.

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