The Stihl 028 is a professional-grade chainsaw known for its reliability and power. This service manual provides comprehensive instructions for maintenance, troubleshooting, and repair of the Stihl 028 chainsaw, including the 028 AV Super model. It covers engine specifications, fuel system, ignition system, chain brake, lubrication, and electrical components. Below are key sections for safety, specifications, maintenance procedures, troubleshooting, and parts diagrams.
Always wear protective equipment: safety glasses, gloves, hearing protection, and chainsaw chaps. Work in a well-ventilated area. Disconnect spark plug before servicing. Use genuine Stihl parts.
| Hazard | Prevention |
|---|---|
| Fuel fire/explosion | No smoking; fuel outdoors only |
| Chain contact | Engage chain brake when not cutting |
| Kickback | Use reduced-kickback chain; grip firmly |
| Carbon monoxide | Operate outdoors only |
| Hot surfaces | Allow engine to cool before servicing |
Daily/Before Use: Check chain tension, sharpness, lubrication. Weekly: Clean air filter, check spark plug. Monthly: Clean cooling fins, inspect fuel filter. Annually: Replace spark plug, clean carburetor, check clutch and sprocket.
WARNING! Use only Stihl-approved lubricants and fuels.
Cylinder & Piston: Inspect for scoring; replace if worn. Carburetor Adjustment: Use tachometer for idle (2800 RPM) and high speed (13,500 RPM max). Muffler: Clean spark arrestor screen every 50 hours.
Compression Test: Should be 120-150 psi. Low compression indicates worn piston/rings.
Fuel Tank: Clean annually. Fuel Lines: Replace if cracked or leaking. Carburetor (Walbro or Zama): Clean jets; rebuild kit includes gaskets, diaphragms. Fuel Filter: Located in tank; replace when clogged.
CAUTION! Drain fuel before storing over 30 days to prevent varnish.
Ignition Module: Test with multimeter (primary resistance 0.5-1.5 Ω). Spark Plug: BPMR7A (NGK) or equivalent, gap 0.5 mm. Stop Switch: Check continuity. Flywheel: Torque to 40 Nm (30 ft-lbs).
Chain Tension: Adjust so chain snaps back when pulled. Bar: Flip monthly for even wear; clean groove and oil holes. Sprocket: Replace if worn (clutch drum sprocket). Chain Brake: Test function; replace band if damaged.
Tip: Lubricate chain with oil at every refueling.
| Symptom | Possible Cause | Corrective Action |
|---|---|---|
| Engine won't start | No spark, fuel, or compression | Check spark plug, fuel filter, carburetor, compression. |
| Engine runs poorly | Clogged air filter, carb adjustment | Clean air filter; adjust carburetor H/L screws. |
| Chain doesn't turn | Clutch worn, sprocket damaged | Inspect clutch springs/shoes; replace sprocket. |
| Excessive vibration | Loose parts, unbalanced chain | Tighten bolts; balance chain; check anti-vibration mounts. |
| Oil not lubricating | Clogged oiler, wrong oil | Clean oil passages; use Stihl chain oil. |
Refer to manual for exploded views: Cylinder group, crankcase, fuel system, ignition, clutch, chain brake, handle, bar & chain. Part numbers listed for ordering.
Note: Use torque wrench for accurate tightening.
Stihl limited warranty applies when serviced by authorized dealers. For technical support, contact Stihl USA at 1-800-467-8445 or visit www.stihlusa.com. Manual part number: 0000 400 4703. Copyright © Stihl Incorporated. All rights reserved.