STIHL BG55 Parts Manual

The STIHL BG55 is a professional-grade handheld leaf blower designed for demanding residential and commercial applications. This parts manual provides detailed exploded views, part numbers, and ordering information for the BG55 blower, including the engine assembly, fuel system, ignition system, air filtration, carburetion, starter assembly, fan housing, exhaust system, controls, and housing components. Below are key sections for identification, assembly groups, ordering, and maintenance.

1. Product Identification & Safety 2. Engine Assembly Parts 3. Fuel System Parts 4. Ignition & Electrical Parts 5. Air Filtration & Carburetor Parts 6. Starter Assembly Parts 7. Fan Housing & Blower Tube Parts 8. Exhaust System Parts 9. Controls & Housing Parts 10. Fasteners & Hardware 11. Parts Ordering & Exploded Views

Product Identification & Safety

Locate the serial number on the engine housing. Always refer to this number when ordering parts. Use only genuine STIHL replacement parts.

ComponentDescription
Model DesignationSTIHL BG55 Handheld Leaf Blower
Engine Type2-stroke, single-cylinder, air-cooled
Displacement27.2 cc (1.66 cu. in.)
Ignition SystemElectronic, capacitor discharge (CDI)
Fuel/Oil Mix50:1 (STIHL HP Ultra oil recommended)
Serial Number LocationStamped on engine housing near muffler
Safety SymbolsRefer to original operator's manual for all safety warnings
Personal Protective EquipmentAlways wear eye and hearing protection during operation

Engine Assembly Parts

Crankcase, cylinder, piston, connecting rod, crankshaft, bearings, and seals.

  1. Cylinder Assembly: Includes cylinder, cylinder head, and mounting studs.
  2. Piston Assembly: Piston, piston rings, wrist pin, and circlips.
  3. Crankshaft Assembly: Crankshaft, main bearings, and oil seals.
  4. Crankcase: Upper and lower halves with gasket.

WARNING! Engine disassembly requires special tools and expertise. Incorrect assembly can cause engine failure or personal injury.

Fuel System Parts

Fuel tank, cap, lines, filter, and primer bulb.

  1. Fuel Tank: Polyethylene tank with integrated mounting points.
  2. Fuel Cap: Venting type with tether.
  3. Fuel Lines: Supply and return lines (different diameters).
  4. Fuel Filter: In-tank sintered bronze filter.
  5. Primer Bulb: For carburetor pre-filling.

CAUTION! Use only ethanol-resistant fuel lines. Inspect lines regularly for cracks and replace as a set.

Ignition & Electrical Parts

Air Filtration & Carburetor Parts

Air filter, cover, carburetor, and intake components.

Air Filter: Felt and foam dual-stage filter element. Carburetor: Zama C1Q-S series diaphragm carburetor. Includes gaskets, diaphragms, metering lever, needle valve, and adjustment screws (LA, H, idle).

Install: Ensure all gaskets are properly seated. Adjust: Final carburetor adjustment should be performed with a tachometer.

Starter Assembly Parts

Rewind starter, pulley, spring, rope, and handle.

  1. Turn off unit and allow to cool before servicing starter.
  2. Disassemble in a controlled manner; starter spring is under tension.
  3. Replace frayed starter rope immediately.

Tip: Lubricate starter pulley bushing with light grease during reassembly.

Fan Housing & Blower Tube Parts

Impeller, fan housing, blower tube, and nozzle.

  1. Impeller: Plastic fan; inspect for cracks or missing blades.
  2. Fan Housing: Directs airflow; includes mounting points to engine.
  3. Blower Tube: Two-part telescoping tube with locking mechanism.
  4. Nozzle: Concentrates airflow; replace if cracked.
  5. Anti-Vibration Elements: Rubber mounts between engine and housing.
  6. Air Intake Cover: Protects fan and directs cooling air.

WARNING! Do not operate with damaged impeller or housing. Can cause catastrophic failure.

Exhaust System Parts

Muffler, spark arrestor screen, gasket, and mounting hardware.

Muffler: Reduces noise and directs exhaust. Spark Arrestor: Mesh screen (must be cleaned regularly to prevent carbon buildup). Gasket: Seal between cylinder and muffler.

Controls & Housing Parts

Throttle trigger, lockout lever, throttle cable, main housing, and handles.

CAUTION! Ensure throttle cable moves freely and returns to idle automatically. Replace kinked or frayed cables.

Fasteners & Hardware

All screws, nuts, washers, clips, and retainers specific to the BG55. Most are metric. Use correct torque specifications.

Copyright © 2025 STIHL. STIHL is a registered trademark. For genuine parts, see your authorized STIHL dealer. For support, visit www.stihlusa.com or contact 1-800-467-8445.

Parts Ordering & Exploded Views

Symptom / Part NeededReferenceAction
Engine won't startFuel/Carb/Ignition GroupsCheck spark, fuel delivery, and carburetor diaphragms using exploded views 2, 3, 5, 6.
Loss of power/airflowFan/Exhaust GroupsInspect impeller and muffler screen using views 7 & 9.
Fuel leakFuel System GroupReplace fuel lines, tank, or cap using view 4.
Excessive vibrationAV Mounts/FanCheck anti-vibration mounts and impeller balance using views 7 & 10.
Starter rope brokenStarter GroupReplace rope and spring using view 7.

Ordering: Use the 11-digit STIHL part number from the illustrated parts list. Provide serial number to dealer.

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

STIHL BG55 Parts Manual © - All Rights Reserved 2025