The Jonsered 2050 is a professional-grade chainsaw designed for demanding forestry and arborist work. This parts manual provides comprehensive diagrams, part numbers, and ordering information for the complete assembly, including the engine, cutting system, fuel system, ignition, and safety components. Below are key sections for identification, engine parts, cutting attachment, fuel system, ignition system, and maintenance.
Locate the model and serial number plate on the rear of the saw body, near the handle. Key specifications for the Jonsered 2050.
| Feature | Description |
|---|---|
| Engine Displacement | 50.1 cm³ (3.06 cu. in.) |
| Power Output | 3.0 kW (4.0 hp) |
| Fuel Tank Volume | 0.55 L (18.6 fl. oz.) |
| Oil Tank Volume | 0.26 L (8.8 fl. oz.) |
| Recommended Guide Bar Length | 40 cm (16 in.) - 50 cm (20 in.) |
| Chain Pitch | 3/8" or .325" |
| Chain Gauge | 1.5 mm (.058") or 1.3 mm (.050") |
| Ignition System | Electronic (CDI) |
| Weight (Powerhead only) | 5.2 kg (11.5 lbs) |
| Sound Power Level (LWA) | 114 dB(A) |
Overall exploded view showing the relationship between major assemblies.
WARNING! Always disconnect the spark plug wire before disassembling any parts. Use proper tools to avoid injury.
Detailed parts list for the engine block, piston, cylinder, and crankshaft.
CAUTION! Ensure all gaskets (Part # 503 25 51-02) are replaced during reassembly to prevent air leaks.
Components for fuel delivery and mixture. Carburetor: Zama C1M or Walbro equivalent.
Fuel Tank: Part # 501 87 65-01. Includes tank vent (Part # 503 22 72-01). Fuel Filter: In-tank, Part # 503 22 73-01. Fuel Line: 3mm ID, Part # 503 22 74-01. Carburetor Kit: Includes gaskets, diaphragms, needle valve. Kit # 503 22 75-01. Air Filter: Dual-stage foam/felt. Part # 501 87 66-01.
CDI ignition module, spark plug, wiring, and stop switch.
Tip: Check for cracked insulation on wires and secure connections.
Recoil starter housing, rope, pulley, and spring.
WARNING! The recoil spring is under high tension. Wear safety glasses and gloves when servicing.
Inertia-activated chain brake parts list and inspection points.
Critical fastener torque values. Use a calibrated torque wrench.
CAUTION! Overtightening can strip threads; undertightening can cause failure.
| Fastener | Torque (Nm) | Torque (ft-lbs) |
|---|---|---|
| Cylinder Base Nuts | 10-12 | 7.4-8.9 |
| Spark Plug | 20-25 | 14.8-18.4 |
| Clutch Nut | 35-40 | 25.8-29.5 |
| Guide Bar Nuts | 9-11 | 6.6-8.1 |
| Flywheel Nut | 40-45 | 29.5-33.2 |
| Starter Housing Screws | 4-5 | 3.0-3.7 |
Always provide the model number (2050), serial number, and the part number from this manual when ordering. Contact an authorized Jonsered dealer or visit the official parts website. Copyright © Jonsered. Jonsered is a trademark of Husqvarna AB. Parts are subject to change without notice.
| Symptom | Possible Cause | Corrective Action |
|---|---|---|
| Engine will not start | No spark, fuel, or compression | Check spark plug, fuel filter, carburetor diaphragm, and cylinder compression. |
| Engine runs poorly | Clogged air filter, incorrect carb adjustment | Clean/replace air filter; adjust H and L needles per manual. |
| Chain does not turn | Clutch worn, sprocket damaged, brake engaged | Inspect clutch shoes and springs; check sprocket; disengage chain brake. |
| Excessive vibration | Loose components, unbalanced chain, damaged AV mounts | Tighten all fasteners; balance chain; inspect anti-vibration mounts (Part # 503 22 80-01). |
| Oil not feeding to bar | Clogged oil passages, faulty pump, wrong oil | Clean oil ports; inspect oil pump (Part # 501 87 71-01); use recommended bar & chain oil. |
Warranty: Refer to your original Jonsered warranty documentation. Typically 1 year commercial, 2 year private use.
Service: For technical support, contact your local authorized Jonsered service center.