The Husqvarna FS520 is a professional-grade string trimmer/brushcutter designed for demanding clearing and maintenance work. This parts manual provides detailed diagrams, part numbers, and ordering information for the FS520 powerhead, cutting attachments, and related accessories. It is intended for authorized service technicians and end-users to assist in the identification, maintenance, and repair of the unit. Below are key sections covering safety, components, assembly, and parts lists.
This manual contains proprietary information for the Husqvarna FS520. Always refer to the original operator's manual for safety and operating instructions before use.
| Safety Symbol | Meaning |
|---|---|
| ⚠️ WARNING | Indicates a potentially hazardous situation which, if not avoided, could result in death or serious injury. |
| ⚠️ CAUTION | Indicates a potentially hazardous situation which, if not avoided, may result in minor or moderate injury or property damage. |
| ℹ️ NOTE | Indicates important information, tips, or conditions for correct operation. |
WARNING! Always disconnect the spark plug cap before performing any maintenance or parts replacement. Use only genuine Husqvarna replacement parts.
Reference diagram for main housing, covers, and structural components.
CAUTION! Ensure all screws and fasteners are tightened to specified torque values during reassembly.
Cylinder, piston, crankshaft, and connecting rod assembly.
| Part Number | Description | Qty |
|---|---|---|
| 503 87 47-01 | Cylinder, Complete | 1 |
| 503 87 48-01 | Piston Assembly (including rings, pin, circlips) | 1 |
| 501 84 43-02 | Crankshaft Assembly | 1 |
| 530 03 09-25 | Main Bearings (set) | 1 |
| 501 84 44-01 | Connecting Rod | 1 |
| 530 03 10-25 | Crankcase Seal Kit | 1 |
Components for fuel delivery and mixture. The FS520 typically uses a Walbro or Zama carburetor.
Tip: Always clean the air filter and check the fuel filter regularly for optimal performance.
Components responsible for generating spark.
WARNING! Never test for spark with the spark plug removed and the electrode grounded against the cylinder unless the fuel system is disconnected. Risk of fire.
Transmits power from the engine to the cutting attachment.
| Part Number | Description | Notes |
|---|---|---|
| 537 33 70-01 | Drive Shaft, Complete | Rigid type |
| 501 87 80-01 | Gearbox Housing | Bevel gear, 28:1 ratio |
| 530 03 11-25 | Gear Set (Pinion & Bevel Gear) | Includes shims |
| 530 03 12-25 | Gearbox Seal Kit | Prevents oil leaks |
| 501 87 81-01 | Output Shaft | Attachment point for trimmer head/blade |
Parts for the standard trimmer head and optional blades.
CAUTION! Always use the correct guard for the cutting attachment. Ensure the blade is sharp, balanced, and undamaged.
Components for operator control and comfort.
Recommended service intervals for key components.
| Component | Daily/Before Use | Every 50 Hours | Every 100 Hours/Season |
|---|---|---|---|
| Air Filter | Check, clean if dirty | Clean | Replace |
| Spark Plug | Visual check | Clean, check gap | Replace |
| Fuel Filter | - | - | Replace |
| Gearbox Grease | Check for leaks | - | Re-grease (specific grease) |
| External Screws/Nuts | Check tightness | Tighten | - |
| Carburetor Adjustment | - | Check idle & max speed | Service if needed |
Always provide the model number (FS520) and serial number when ordering parts. Serial number is located on a decal on the engine housing.
Genuine Husqvarna Parts: Designed to meet original specifications for safety, performance, and durability.
Warranty: Husqvarna branded products are covered by a commercial warranty. Proof of purchase from an authorized dealer is required. Warranty does not cover parts damaged by misuse, lack of maintenance, or use of non-genuine parts.
Support: For technical assistance, parts diagrams, and dealer location, visit www.husqvarna.com or contact your local authorized Husqvarna service dealer.