Husqvarna FS 6600 Parts Manual

The Husqvarna FS 6600 is a professional-grade string trimmer/brushcutter designed for demanding clearing and maintenance tasks. This parts manual provides detailed diagrams, part numbers, and ordering information for all major assemblies and components to facilitate maintenance, repair, and safe operation of your FS 6600 power cutter. Below are key sections covering safety, identification, engine parts, cutting attachments, and maintenance schedules.

1. Safety Information & Symbols 2. Machine Identification & Specifications 3. Engine Assembly & Components 4. Drive Shaft & Gear Housing 5. Cutting Attachments & Guard 6. Handle & Control Systems 7. Fuel System & Air Filter 8. Ignition & Electrical System 9. Maintenance Schedule & Lubrication 10. Torque Specifications 11. Parts Ordering & Exploded Views

Safety Information & Symbols

Critical safety warnings and explanations of symbols found on the machine and in the manual.

SymbolDescription
⚠️General Warning - Read the manual before operation.
🔥Fire Hazard - Keep away from flammable materials; let engine cool before refueling.
💨Exhaust Fumes - Operate only in well-ventilated areas.
🛑Thrown Objects/Debris - Always wear eye and leg protection. Ensure guard is installed.
🔧Maintenance Alert - Disconnect spark plug before performing maintenance.
📏Safe Distance - Keep bystanders at least 15 meters away during operation.

WARNING! Failure to follow safety instructions can result in serious injury or death. Always use genuine Husqvarna parts.

Machine Identification & Specifications

Locate your model and serial number for accurate parts identification.

  1. Model: FS 6600
  2. Serial Number Location: Stamped on the engine block or gear housing.
  3. Engine Type: 2-stroke, air-cooled.
  4. Displacement: 94.3 cc (5.75 cu. in.)
  5. Power Output: 4.4 kW (6.0 hp)
  6. Fuel/Oil Ratio: 50:1 (Husqvarna XP+ 2-stroke oil recommended).
  7. Recommended Fuel: Minimum 90 Octane unleaded gasoline.
  8. Drive System: Solid drive shaft with bevel gear.
  9. Standard Cutting Attachment: Metal blade or heavy-duty trimmer head.
  10. Weight (without attachment): Approx. 9.8 kg (21.6 lbs).

Engine Assembly & Components

Detailed parts list for the 2-stroke engine assembly (Cylinder, Piston, Crankshaft).

Note: Use a torque wrench when assembling engine components. Refer to Section 10 for values.

Drive Shaft & Gear Housing

Parts for the power transmission from the engine to the cutting attachment.

Part DescriptionPart NumberQty
Solid Drive Shaft537 27 45-011
Drive Shaft Tube (Upper)537 27 46-011
Bevel Gear Set (17T/17T)537 27 47-011 Set
Gear Housing (Complete)537 27 48-011
Output Shaft & Bearing537 27 49-011
Grease Seal Kit537 27 50-011 Kit
Lock Nut (Output Shaft)537 27 51-011

Tip: Pack gear housing with high-quality grease (Husqvarna Grease) during assembly.

Cutting Attachments & Guard

Parts for the cutting head, blades, and safety guard.

  1. Blade Adapter/Lock Nut: Secures blade to output shaft.
  2. Circular Metal Blades: 3-tooth, 8-tooth, or multi-tooth blades for clearing.
  3. Heavy-Duty Trimmer Head: For heavy grass and brush (e.g., Husqvarna T35).
  4. Safety Guard: Deflector guard; must be correctly installed for operation.
  5. Guard Mounting Kit: Bolts, washers, and brackets.
  6. Blade Washer & Spacer Set: Ensures proper blade alignment and tension.

WARNING! Always use the correct guard for the attachment. Never operate without a guard.

Handle & Control Systems

Parts for the loop handle, controls, and harness attachment points.

Handle Assembly: Includes handlebar, vibration dampeners, and mounting clamp.

Throttle Control: Throttle trigger, throttle cable, lockout lever, and return spring.

Stop Switch: Ignition kill switch and wiring.

Harness Hooks & D-Rings: Attachment points for carrying harness.

Handle Screws & Bushings: All necessary hardware for assembly.

Fuel System & Air Filter

Components for fuel delivery and air intake.

  1. Fuel Tank: Polyethylene tank with cap and vent.
  2. Fuel Line Kit: Includes all fuel lines and primer bulb.
  3. Carburetor Kit: Complete carburetor (Zama C1U) or rebuild kit (diaphragms, gaskets, needle valve).
  4. Air Filter: Foam pre-filter and paper main filter element.
  5. Air Filter Cover: Cover with retaining clips or screw.

CAUTION! Use only clean, fresh fuel. Stale fuel is a common cause of starting and performance issues.

Ignition & Electrical System

Parts for starting and stopping the engine.

ComponentPart NumberFunction
Ignition Module (CDI)537 27 52-01Provides spark to the plug.
Spark Plug (NGK BPMR7A)537 27 53-01Standard plug. Gap: 0.5 mm (0.020 in).
Stop Switch Assembly537 27 54-01Grounds ignition to stop engine.
Wiring Harness537 27 55-01Connects switch to module.

Tip: Check spark plug condition and gap regularly. Replace if electrodes are worn.

Maintenance Schedule & Lubrication

Recommended service intervals for optimal performance and longevity.

Lubrication Points: Gear housing (grease), drive shaft joints (light oil), throttle linkage (light oil).

Torque Specifications

Critical fastener torque values to ensure safe and reliable assembly.

Fastener LocationTorque (Nm)Torque (ft-lbs)
Cylinder Head Nuts20-2214.8-16.2
Spark Plug25-3018.4-22.1
Output Shaft Lock Nut60-7044.3-51.6
Blade Mounting Nut35-4525.8-33.2
Handle Clamp Bolts15-1811.1-13.3
Gear Housing Screws8-105.9-7.4

Note: Use a calibrated torque wrench. Do not overtighten.

Parts Ordering & Exploded Views

How to order parts and use the exploded view diagrams.

  1. Always provide the Model (FS 6600) and Serial Number.
  2. Reference the relevant exploded view diagram number (e.g., "Fig. 3: Engine Assembly").
  3. Use the listed Part Number when ordering from an authorized Husqvarna dealer.
  4. Diagrams show the relationship and quantity of parts in each assembly.

Reset: For persistent engine issues, a factory reset of carburetor settings may be required.

Service & Support: Contact an authorized Husqvarna service dealer. For dealer locator and manuals: www.husqvarna.com.

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