STIHL 011 Chainsaw Repair Manual

The STIHL 011 is a professional-grade gasoline-powered chainsaw designed for demanding cutting tasks. This repair manual provides comprehensive information for maintenance, troubleshooting, and repair of the STIHL 011 chainsaw, including the engine, fuel system, ignition, chain drive, and safety components. Below are key sections covering safety, specifications, disassembly, maintenance procedures, and troubleshooting.

1. Safety Precautions 2. Specifications 3. Tools Required 4. Engine Disassembly 5. Fuel System Repair 6. Ignition System 7. Chain & Bar Maintenance 8. Carburetor Adjustment 9. Reassembly Guide 10. Troubleshooting 11. Parts Diagram

Safety Precautions

Always prioritize safety when performing repairs on a chainsaw.

PrecautionDescription
Disconnect Spark PlugAlways disconnect the spark plug wire before beginning any repair to prevent accidental starting.
Work in Well-Ventilated AreaGasoline fumes are flammable and hazardous; ensure proper ventilation.
Wear Protective GearUse safety glasses, gloves, and appropriate clothing to protect against sharp edges and debris.
Drain FuelDrain the fuel tank before working on the fuel system or carburetor.
Secure the ChainsawClamp or secure the saw in a stable position to prevent movement during repair.
Handle Sharp Components CarefullyThe chain and guide bar are extremely sharp; handle with heavy gloves.
Use Genuine STIHL PartsFor optimal performance and safety, use only STIHL-approved replacement parts.
Refer to Torque SpecificationsUse a torque wrench when reassembling critical components like cylinder head or clutch.

Specifications

Tools Required

Basic and specialized tools needed for repair.

  1. Spark Plug Wrench
  2. Socket Set (Metric: 8mm, 10mm, 13mm)
  3. Screwdrivers (Flathead and Phillips)
  4. Torx or Hex Key Set (for case screws)
  5. Compression Gauge
  6. Multimeter (for ignition testing)
  7. Carburetor Adjustment Tool (splined)
  8. Piston Stop Tool (for flywheel removal)
  9. Flywheel Puller (STIHL-specific or universal)
  10. Clutch Removal Tool (or appropriate spanner)

WARNING! Using incorrect tools can damage components. Use tools that fit properly.

Engine Disassembly

Step-by-step guide to disassemble the engine for major repairs.

  1. Remove the top cover and air filter cover.
  2. Disconnect the spark plug wire and fuel line.
  3. Remove the carburetor and intake manifold.
  4. Remove the muffler and cylinder cover.
  5. Secure the piston at Top Dead Center (TDC) using a piston stop.
  6. Remove the flywheel nut and use a puller to remove the flywheel.
  7. Remove the ignition coil and associated wiring.
  8. Unbolt and remove the cylinder from the crankcase.
  9. Remove the piston and connecting rod from the crankshaft (inspect wrist pin and bearing).
  10. For crankcase separation, remove all case screws and carefully separate halves.

CAUTION! Label or photograph all parts and connections during disassembly for correct reassembly.

Fuel System Repair

Diagnosing and repairing fuel delivery issues.

Components: Fuel tank, fuel filter, fuel lines, primer bulb (if equipped), carburetor.

  1. Inspect fuel lines for cracks, brittleness, or leaks. Replace if necessary.
  2. Check the fuel filter inside the tank; replace if clogged.
  3. Clean the carburetor: Disassemble, soak in carburetor cleaner, and blow out all passages with compressed air.
  4. Inspect the carburetor diaphragms and gaskets for tears or stiffness; replace the carburetor repair kit if needed.
  5. Test the fuel pump function by operating the primer bulb (if present) and checking for fuel flow.
  6. Ensure the tank vent is not clogged.

Tip: Always use fresh, properly mixed fuel to prevent carburetor issues.

Ignition System

Testing and replacing ignition components.

ComponentTest ProcedureSpecification
Spark PlugInspect electrode gap (0.5mm / 0.020"). Clean or replace.NGK BPMR7A or equivalent.
Ignition CoilUse multimeter to check primary and secondary resistance.Primary: ~0.5-2 Ω; Secondary: ~5-15 kΩ (refer to manual).
Flywheel & MagnetsInspect for cracks or damage. Check air gap between coil and flywheel (0.2-0.4mm).Magnets must be strong; replace if weak.
Stop Switch WireCheck for continuity to ground when switch is off; should be open circuit when on.Repair or replace broken wires.

WARNING! A weak spark can cause hard starting or poor performance. Replace faulty components.

Chain & Bar Maintenance

Proper care of the cutting system.

  1. Chain Sharpening: Use a round file matching the chain pitch. Maintain correct filing angle (typically 30°).
  2. Bar Maintenance: Clean the bar groove and oil holes. Flip the bar regularly for even wear.
  3. Chain Tension: Adjust so the chain snaps back lightly when pulled from the bar. It should not sag.
  4. Sprocket Inspection: Check the drive sprocket (rim or spur) for wear; replace if teeth are hooked.
  5. Oil System: Ensure the automatic oiler is working. Clean oil passages and check oil pump function.

CAUTION! A dull or loose chain is dangerous and increases the risk of kickback.

Carburetor Adjustment

Setting the idle, low-speed (L), and high-speed (H) mixture screws.

Initial Settings (if carburetor was rebuilt): Turn both L and H screws gently clockwise until seated, then back out 1 turn each. Idle speed screw: back out until throttle plate just closes.

  1. Start the engine and let it warm up for several minutes.
  2. Idle Speed (LA or T): Adjust so chain does not move and engine runs smoothly.
  3. Low-Speed (L) Mixture: Adjust for fastest, smoothest idle, then enrich slightly (turn counterclockwise) for good acceleration.
  4. High-Speed (H) Mixture: Under load (cutting), adjust for maximum power without leaning out (high RPM with no "four-stroking" sound).
  5. Re-check idle speed after mixture adjustments.

WARNING! An overly lean H mixture can cause engine seizure. Always final-tune under load.

Reassembly Guide

Critical steps for reassembling the chainsaw.

  1. Clean all parts thoroughly before assembly.
  2. Lubricate the crankshaft bearings and piston rings with 2-stroke oil.
  3. Install new crankcase seals and gaskets.
  4. Assemble crankcase halves, ensuring proper alignment. Torque case screws in a crisscross pattern to specification.
  5. Install the cylinder, using a new base gasket. Torque cylinder nuts evenly.
  6. Install the piston with the arrow facing the exhaust port. Secure with circlips.
  7. Install the flywheel, tightening the nut to the specified torque.
  8. Set the ignition coil air gap using a feeler gauge.
  9. Reinstall the carburetor, fuel lines, and air filter assembly.
  10. Fill with fresh fuel mix, start, and adjust carburetor as described in Section 9.

Tip: Perform a compression test after reassembly. Good compression should be above 120 psi.

Troubleshooting

SymptomPossible CauseCorrective Action
Engine won't startNo spark, flooded, fuel issueCheck spark, dry plug, verify fuel delivery and compression.
Engine starts then diesClogged fuel filter, bad fuel line, carburetor issueInspect fuel system, clean/replace filter/lines, rebuild carb.
Lacks power under loadClogged air filter, exhaust port carbon, lean H mixtureClean air filter, decarbonize muffler/ports, adjust H screw.
Chain does not oilClogged oil passages, faulty oil pump, empty tankClean bar groove/holes, check pump drive, fill oil.
Excessive vibrationLoose components, unbalanced flywheel, worn AV mountsTighten all fasteners, inspect flywheel, replace anti-vibration mounts.
Engine runs unevenly or surgesAir leak, dirty carburetor, faulty ignitionPressure test crankcase, clean carb, check coil/wiring.

Reset: After major repairs, reset carburetor to factory settings and retune.

Service: For genuine parts and technical support, contact an authorized STIHL dealer.

Parts Diagram

Refer to the official STIHL 011 IPL (Illustrated Parts List) for exploded views and part numbers. Key assembly groups include:

Note: Always use the correct part number when ordering replacements. Serial number of your saw may be required.

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