STIHL BR 400 Parts Manual

The STIHL BR 400 is a professional-grade backpack blower designed for demanding commercial and residential use. This parts manual provides detailed diagrams, part numbers, and ordering information for all components of the BR 400 blower, including the engine assembly, fan housing, throttle controls, fuel system, carrying harness, and muffler. It is intended for authorized service technicians and users performing maintenance or repairs. Below are key sections for identification, engine parts, blower tube assembly, controls, fuel system, and ordering.

1. Machine Identification & Specifications 2. Safety & General Information 3. Engine Assembly Parts 4. Fan Housing & Impeller 5. Blower Tube & Nozzle 6. Throttle Control & Handle Assembly 7. Fuel System & Carburetor 8. Carrying Harness & Frame 9. Muffler & Exhaust System 10. Fasteners, Decals & Miscellaneous 11. Parts Ordering & Exploded Views

Machine Identification & Specifications

Locate the serial number plate on the blower housing. Key specifications: 2-stroke engine, displacement, air volume, and maximum air speed.

Feature	Description
Model	STIHL BR 400
Engine Type	2-stroke, single-cylinder, air-cooled
Displacement	64.8 cm³ (3.95 cu. in.)
Power Output	2.5 kW (3.4 hp)
Maximum Air Speed	Approx. 300 km/h (186 mph)
Air Volume	Approx. 1,100 m³/h (647 cfm)
Fuel/Oil Mix	50:1 (STIHL HP Ultra oil)
Dry Weight	Approx. 9.5 kg (20.9 lbs)
Sound Power Level	112 dB(A)
Vibration Levels	Left/Right Handle: m/s²

Safety & General Information

Before disassembly, read the original instruction manual. Use genuine STIHL parts only.

Safety: Disconnect spark plug boot before working. Allow engine to cool.
Tools: Use appropriate STIHL or equivalent tools (e.g., splined socket for clutch).
Torque Values: Refer to specifications; do not overtighten.
Cleanliness: Keep work area clean; prevent dirt from entering engine.

WARNING! Risk of injury. Use proper personal protective equipment (PPE). Fuel is highly flammable.

Engine Assembly Parts

Cylinder, piston, crankshaft, connecting rod, bearings, seals, and crankcase components.

Cylinder: Part number 1128 020 2001 (with cylinder fins).
Piston: Part number 1128 030 2001 (includes rings and wrist pin).
Crankshaft: Part number 1128 040 2005.
Crankcase: Part number 1128 050 2001 (includes halves).
Main Bearings & Seals: Refer to exploded view for numbers.

Note: Always replace crankshaft seals when rebuilding engine.

Fan Housing & Impeller

Fan Housing: Part number 4128 851 0600. Includes air intake cover.
Impeller (Fan Wheel): Part number 4128 852 0601. Balanced assembly.
Impeller Nut: Part number 9012 851 6010. Left-hand thread.
Clutch Assembly: Part number 1128 160 2001. Centrifugal type.
Starter Housing: Part number 4128 855 0600. Includes recoil mechanism.
Anti-Vibration Mounts: Part numbers vary; replace in sets.

Blower Tube & Nozzle

Tube sections, locking rings, and nozzle components.

Main Tube: Part number 4128 771 0600. Extension Tube: Part number 4128 772 0600. Nozzle: Part number 4128 773 0601. Locking Lever: Part number 4128 774 0600. Tube Seal: Part number 4128 775 0600.

Assembly: Insert tube into housing, align marks, engage locking lever until secure.

Throttle Control & Handle Assembly

Throttle trigger, cable, lockout, handle, and control levers.

Turn off engine and remove spark plug boot.
Remove handle cover screws to access throttle linkage.
Disconnect throttle cable from carburetor lever.
Replace worn trigger or cable (Part number 1128 131 2000 for cable).
Reassemble, ensuring throttle moves freely and returns.

Tip: Lubricate throttle cable ends with light oil during assembly.

Fuel System & Carburetor

Fuel tank, cap, filter, lines, carburetor, and purge bulb.

Fuel Tank: Part number 4128 351 0600. Includes mounting points.
Fuel Cap: Part number 0000 350 3505. Ventilated.
Fuel Filter: Part number 0000 350 3501. In-tank type.
Carburetor (C1Q-S167): Part number 1128 120 2002. Includes gaskets.
Purge Bulb: Part number 1128 121 2000.
Fuel Lines: Part numbers 1128 122 2000 (supply) and 1128 123 2000 (return).

WARNING! Drain fuel before servicing. Use only ethanol-resistant fuel lines.

Carrying Harness & Frame

Harness straps, buckles, back pad, and frame connections.

Muffler & Exhaust System

Muffler body, spark arrestor screen, gasket, and mounting bolts.

CAUTION! Muffler gets extremely hot. Allow to cool completely before handling.

Fasteners, Decals & Miscellaneous

STIHL uses specific screws, washers, and clips. Decals include safety warnings and model identification.

Fastener Kit: Part number 9005 850 7720 (example). Decal Set: Part number 4128 891 0600. Spark Plug: BOSCH WSR 6 F or equivalent. Air Filter: Part number 1128 140 2001.

Parts Ordering & Exploded Views

Symptom / Part Needed	Diagram Reference	Ordering Information
Engine will not start	Group 1: Engine	Check spark plug, fuel filter, carburetor diaphragm.
Loss of air power	Group 4: Fan Housing	Inspect impeller for damage/cracks; check tube seals.
Excessive vibration	Group 5: Anti-Vibration	Replace all anti-vibration mounts and dampers.
Throttle stuck/binding	Group 6: Controls	Replace throttle cable and lubricate linkage.
Fuel leak	Group 7: Fuel System	Replace fuel lines, tank grommet, or carburetor gaskets.

Exploded Views: Refer to official STIHL BR 400 IPL (Illustrated Parts List) for detailed diagrams.

Genuine Parts: Order through authorized STIHL dealers only. Provide model and serial number.