The Stihl 020 AV is a professional-grade chainsaw featuring anti-vibration (AV) technology, a robust engine design, and durable construction for demanding forestry and arborist work. This service manual provides comprehensive instructions for maintenance, troubleshooting, repair, and safety procedures. Below are key sections covering specifications, maintenance schedules, engine service, fuel system, ignition, carburetor, chain and bar, troubleshooting, and parts diagrams.
Key technical specifications for the Stihl 020 AV chainsaw.
| Feature | Description |
|---|---|
| Engine Type | Single-cylinder, two-stroke, air-cooled |
| Displacement | 35.2 cc (2.15 cu. in.) |
| Power Output | Approx. 2.0 kW (2.7 hp) |
| Fuel Tank Capacity | 0.55 L (18.6 fl. oz.) |
| Oil Tank Capacity | 0.26 L (8.8 fl. oz.) |
| Guide Bar Lengths | 12" to 16" (30 cm to 40 cm) |
| Chain Pitch | 3/8" PM or .325" |
| Ignition System | Electronic, breakerless |
| Weight (powerhead) | Approx. 5.2 kg (11.5 lbs) |
| Anti-Vibration System | Stihl AV with rubber dampeners |
Essential safety procedures to follow before and during service.
WARNING! Fuel is highly flammable. No smoking. Drain fuel tank before major disassembly. Handle sharp chain with extreme care.
Recommended service intervals for optimal performance and longevity.
CAUTION! Adherence to the maintenance schedule is critical for safe operation and warranty compliance.
Servicing the fuel tank, lines, filter, and cap.
Components: Fuel tank, fuel filter, fuel lines (supply and return), vented fuel cap.
Procedure: 1. Drain fuel. 2. Remove tank cover. 3. Replace fuel filter and inspect lines for cracks/softness. 4. Clean tank interior. 5. Reassemble, ensuring lines are routed correctly and securely connected.
Testing and replacing the ignition module (coil), spark plug, and stop switch.
Tip: Use a Stihl diagnostic tester (if available) for precise ignition module testing.
Adjusting the Walbro or Zama carburetor. Factory settings are a starting point; final adjustment must be made with a warmed-up engine.
WARNING! An improperly adjusted H screw can cause immediate engine seizure due to lean mixture. Adjust in small increments.
Maintenance for the cutting chain, guide bar, and drive sprocket.
Chain Tension: Correct when chain snaps back after pulling away from bar rail. Adjust via side tensioner.
Bar Maintenance: Clean bar groove, flip bar regularly for even wear, check for "burring" on rails.
Sprocket: Inspect for wear (hook-shaped teeth). Replace if worn to prevent chain damage.
Sharpening: Use correct round file size. Maintain correct filing angle (typically 30°) and depth gauge settings.
Service of the AV mounts and dampeners.
Inspect rubber AV elements for cracking, hardening, or separation. Replace in sets if any are defective. Ensure all mounting bolts are tight to frame. Worn AV mounts transfer excessive vibration to operator.
| Symptom | Possible Cause | Corrective Action |
|---|---|---|
| Engine will not start | No spark, flooded, fuel issue | Check spark, plug condition. Dry plug if flooded. Check fuel flow, filter, lines. |
| Engine starts then dies | Clogged fuel filter, tank vent, carb adjustment | Replace fuel filter. Clean tank vent. Check carburetor L screw setting. |
| Lacks power/overheats | Dirty air filter, clogged muffler, lean H setting | Clean air filter. Clean spark arrestor screen. Richen H screw slightly. |
| Excessive vibration | Worn AV mounts, unbalanced clutch/flywheel, loose parts | Inspect and replace AV mounts. Check clutch balance and tightness. Tighten all fasteners. |
| Chain does not oil | Clogged oil passages, faulty oil pump, empty tank | Clean bar oil hole and saw's oil ports. Test/replace oil pump. Fill oil tank. |
Reset: For electronic issues, disconnect spark plug wire for 1 minute to reset module.
Service: For genuine Stihl parts and technical support, contact an authorized Stihl servicing dealer.