STIHL BR400 Backpack Blower Parts Manual

The STIHL BR400 is a professional-grade backpack blower designed for demanding commercial and residential use. This manual provides detailed parts diagrams, part numbers, and ordering information for the BR400 model. Below are key sections covering safety, parts identification, assembly diagrams, maintenance parts, and ordering procedures.

1. Features at a Glance 2. Safety Information 3. Parts Identification 4. Assembly Diagrams 5. Engine Components 6. Blower Tube & Nozzle 7. Harness & Frame 8. Maintenance Parts 9. Ordering Information 10. Warranty & Support 11. Troubleshooting Parts Guide

Features at a Glance

Key components: 2-stroke engine, backpack harness system, adjustable blower tube, anti-vibration system, and easy-start technology.

FeatureDescription
Engine Type2-stroke, single cylinder, air-cooled
Displacement40.2 cc (2.45 cu. in.)
Power Output1.6 kW (2.2 bhp)
Fuel Tank Capacity1.0 L (33.8 fl. oz.)
Weight (without fuel)9.5 kg (20.9 lbs)
Sound Pressure Level112 dB(A)
Vibration Level (left/right)3.5/4.5 m/s²
Air Speed85 m/s (186 mph)
Air Volume900 m³/h (530 cfm)
Harness SystemPadded backpack with adjustable straps

Safety Information

Always wear appropriate personal protective equipment (PPE) including eye protection, hearing protection, gloves, and sturdy footwear.

  1. Read the operator's manual before assembly or operation.
  2. Use only STIHL-approved parts and accessories.
  3. Ensure the engine is stopped and cool before performing maintenance.
  4. Use only STIHL branded lubricants and fuel mixtures.

WARNING! Improper maintenance or use of non-genuine parts can cause serious injury or damage to the equipment. Always disconnect the spark plug before servicing.

Parts Identification

Refer to the numbered diagrams in this manual to identify parts. Each part has a corresponding part number for ordering.

  1. Engine Assembly: Includes cylinder, piston, carburetor, ignition system.
  2. Blower Housing: Main housing containing the impeller and fan.
  3. Air Filter System: Pre-filter, main filter element, and cover.
  4. Fuel System: Tank, cap, lines, filter, and carburetor components.
  5. Exhaust System: Muffler, spark arrestor screen, and mounting hardware.

CAUTION! Use only STIHL genuine parts to maintain performance and safety standards.

Assembly Diagrams

Engine Components

Part numbers for key engine components. Refer to Diagram 2.

Cylinder Group: Cylinder (1123 140 2001), Piston (1123 030 2001), Piston Rings (1123 030 2002). Crankcase: Crankcase half, left (1123 020 2001), Crankcase half, right (1123 020 2002). Crankshaft: Crankshaft assembly (1123 130 2001). Carburetor: Zama C1Q-S266 (1123 120 2001). Ignition: Ignition coil (1123 400 2001), Spark plug (BP7ES).

Blower Tube & Nozzle

Components for the air delivery system. Refer to Diagram 8.

  1. Blower Tube Assembly: Main tube (1123 790 2001).
  2. Nozzle: Standard nozzle (1123 790 2002), Concentrator nozzle (1123 790 2003).
  3. Tube Clamp: Quick-release clamp (1123 790 2004).
  4. Throttle Cable: Control cable assembly (1123 790 2005).

Tip: Inspect the blower tube and nozzle regularly for cracks or damage that can affect performance.

Harness & Frame

Parts for the backpack frame and harness system. Refer to Diagram 7.

  1. Frame: Main backpack frame (1123 810 2001).
  2. Harness Straps: Shoulder straps, left & right (1123 810 2002/2003).
  3. Waist Belt: Padded waist belt (1123 810 2004).
  4. Padding: Back padding kit (1123 810 2005).
  5. Mounting Brackets: Frame to blower mounting brackets (1123 810 2006).

WARNING! A damaged harness or frame can cause the unit to fall, resulting in injury. Inspect before each use.

Maintenance Parts

Common replacement parts for routine maintenance.

Part DescriptionPart NumberReplacement Interval
Air Filter Element1123 140 200325 hours or as needed
Fuel Filter1123 350 2001100 hours or annually
Spark PlugBP7ES100 hours
Impeller1123 790 2006Inspect for damage
Muffler Spark Arrestor Screen1123 150 200150 hours (clean), 200 hours (replace)
Starter Rope1123 080 2001As needed

Ordering Information

To order parts, contact an authorized STIHL servicing dealer with the part number and serial number of your unit.

  1. Locate the serial number on the blower housing.
  2. Use the diagrams in this manual to identify the required part number.
  3. Provide both numbers to your STIHL dealer.
  4. For warranty claims, proof of purchase from an authorized dealer is required.

CAUTION! Using non-genuine STIHL parts will void the warranty and may compromise safety.

Warranty & Support

STIHL Limited Warranty: 1-year commercial warranty, 2-year consumer warranty from date of retail purchase. Warranty covers defects in material and workmanship. Normal wear items (filters, spark plugs, etc.) are not covered.

For technical support and dealer locations, visit www.stihlusa.com or contact STIHL Incorporated at 1-800-GO-STIHL (1-800-467-8445).

Troubleshooting Parts Guide

SymptomPossible Faulty PartPart Number / Action
Engine will not startSpark plug, Ignition coil, Fuel filterReplace spark plug (BP7ES); test/replace coil (1123 400 2001); replace fuel filter (1123 350 2001).
Loss of powerAir filter, Muffler screen, Piston/cylinderClean/replace air filter (1123 140 2003); clean spark arrestor screen (1123 150 2001); inspect cylinder/piston.
Excessive vibrationImpeller, Engine mountsInspect/replace impeller (1123 790 2006); check/tighten engine mounting bolts.
Air leak at tubeTube clamp, Nozzle gasketTighten/replace quick-release clamp (1123 790 2004); inspect nozzle seal.
Harness strap brokenShoulder strapReplace shoulder strap assembly (1123 810 2002/2003).

Note: For complex repairs, take your BR400 to an authorized STIHL servicing dealer.

Support: 1-800-GO-STIHL; www.stihlusa.com

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