029 Stihl Chainsaw Repair Manual

The Stihl 029 chainsaw is a professional-grade gasoline-powered chainsaw known for its reliability and power. This comprehensive repair manual covers safety procedures, technical specifications, troubleshooting, maintenance, and step-by-step repair instructions for the engine, fuel system, ignition, chain drive, and other critical components. Essential for technicians and experienced users.

1. Safety Precautions 2. Specifications & Identification 3. Tools & Workshop Requirements 4. Routine Maintenance 5. Engine System Repair 6. Fuel System Repair 7. Ignition System Repair 8. Chain & Bar Assembly 9. Clutch & Drive System 10. Troubleshooting Guide 11. Parts List & Diagrams

Safety Precautions

Before any repair, ensure the chainsaw is off, cool, and the spark plug wire is disconnected. Wear appropriate personal protective equipment (PPE).

Hazard	Preventive Action
Fuel Fire/Explosion	Work in well-ventilated area; no sparks or flames; drain fuel before major repairs.
Sharp Chain Injury	Wear cut-resistant gloves; ensure chain brake is engaged; handle by handles only.
Hot Surfaces	Allow engine and muffler to cool completely before disassembly.
Spring Tension	Use proper tools when handling clutch, starter springs; they are under tension.
Electrical Shock	Disconnect spark plug wire and keep away from plug terminal during work.

Specifications & Identification

Identify your model via serial number plate. Key specifications for Stihl 029.

Engine Type: Single cylinder, 2-stroke, air-cooled.
Displacement: 56.5 cc (3.45 cu in).
Power Output: Approx. 3.0 kW (4.0 HP).
Fuel/Oil Mix: 50:1 (Stihl HP Ultra or equivalent).
Ignition System: Electronic, breakerless.
Bar Length Options: 16", 18", 20".
Chain Pitch/Gauge: .325" pitch, .063" gauge (standard).
Weight (Powerhead): Approx. 5.7 kg (12.6 lbs).

Tools & Workshop Requirements

Basic mechanic's tools plus Stihl specialty tools recommended.

Standard Tool Set: Screwdrivers, wrenches (metric), socket set, Torx bits.
Specialty Tools: Stihl piston stop, flywheel puller, clutch tool, compression tester.
Workshop: Clean, organized bench with good lighting. Parts cleaning solvent.
Torque Wrench: Essential for reassembly of cylinder, clutch, and other critical fasteners.

WARNING! Use only Stihl-approved tools for specific tasks to avoid damage.

Routine Maintenance

Regular maintenance prevents major failures and ensures optimal performance.

Daily/Pre-Use: Check chain tension and sharpness; inspect for loose fasteners; check fuel/oil levels.
Weekly/10 hrs: Clean air filter (replace if damaged); clean cooling fins; check spark plug condition.
Monthly/50 hrs: Clean fuel filter; inspect fuel lines for cracks; clean spark arrestor screen in muffler.
Seasonal/100 hrs: Replace spark plug; clean carburetor (external); inspect clutch drum and sprocket.

CAUTION! Always use genuine Stihl replacement parts for filters and plugs.

Engine System Repair

Covers cylinder, piston, crankshaft, and bearings.

Cylinder & Piston Removal: Remove muffler, carburetor, and intake. Use piston stop to hold crankshaft, remove cylinder bolts. Inspect cylinder walls for scoring; measure piston ring end gap.

Crankshaft & Bearings: Requires splitting the crankcase. Use a crankcase splitting tool. Inspect bearings for smooth rotation and no play. Replace seals during reassembly.

Reassembly: Use new gaskets. Lubricate piston rings and cylinder wall with 2-stroke oil. Torque cylinder bolts to specification (typically 20 Nm).

Fuel System Repair

Includes tank, lines, filter, and carburetor (Walbro or Zama).

Drain fuel tank completely.
Remove carburetor cover and air filter assembly.
Disconnect fuel and impulse lines. Note routing for reassembly.
Remove carburetor mounting nuts.
For rebuild: Disassemble diaphragm covers, check diaphragms, gaskets, and needle valve. Clean all jets with compressed air.
Reinstall with new gaskets. Adjust H and L mixture screws to base settings (typically 1 turn out).

Tip: Always replace fuel lines and filter during a carburetor service.

Ignition System Repair

Testing and replacement of ignition module (coil), spark plug, and stop switch.

Testing Ignition Module: Use a spark tester. Disconnect spark plug wire, attach tester, pull starter. Should see strong blue spark. Check air gap between coil legs and flywheel (0.3 mm).

Flywheel Removal: Use flywheel puller. Do not hammer. Inspect magnets for cracks.

Stop Switch Circuit: If saw won't start, disconnect wire from coil to eliminate switch as cause.

Component	Test/Procedure
Spark Plug	Check gap (0.5 mm), replace if electrodes are worn or fouled.
Ignition Coil	Resistance test (primary: ~0.5 Ω, secondary: ~5-10 kΩ). Values outside range indicate failure.

Chain & Bar Assembly

Proper maintenance of cutting attachment is critical for safety and performance.

Bar Maintenance: Clean bar groove weekly. File down burrs on bar rails. Flip bar regularly for even wear.
Chain Sharpening: Use correct round file size (.325" chain uses 4.0 mm file). Maintain correct filing angle (typically 30°). Ensure all cutters are uniform length.
Chain Tension: Adjust so chain snaps back lightly when pulled from bar. Tighten bar nuts after adjustment.
Sprocket (Rim/Sprocket): Inspect for wear. Replace if teeth are hooked or worn unevenly.

WARNING! Always wear gloves when handling chain. A dull chain is dangerous and increases kickback risk.

Clutch & Drive System

Clutch removal, inspection, and drum/sprocket service.

Clutch Removal: Use clutch holding tool. Rotate clutch nut clockwise (left-hand thread) to remove. Inspect clutch shoes for wear and springs for fatigue.

Bearing & Drum: Check clutch drum bearing for smooth rotation. Replace needle bearing if rough. Inspect drum for deep scoring from the chain.

Reassembly: Lubricate bearing. Torque clutch nut to specification (approx. 40 Nm). Ensure chain brake band is correctly positioned if reassembling brake assembly.

Troubleshooting Guide

Symptom	Possible Cause	Corrective Action
Engine won't start	No spark, flooded, fuel issue	Check spark, plug condition. Dry plug, choke off, pull. Check fuel lines, filter, carburetor.
Engine starts then dies	Fuel starvation, air leak	Clean fuel filter, check tank vent. Inspect carburetor diaphragms. Check crankcase seals for leaks.
Loss of power under load	Clogged air filter, exhaust screen, poor compression	Clean/replace air filter. Clean spark arrestor. Perform compression test (should be >120 psi).
Chain won't turn	Clutch worn, sprocket seized, brake engaged	Inspect clutch shoes and springs. Check sprocket bearing. Disengage chain brake.
Excessive vibration	Loose components, unbalanced flywheel, bent crankshaft	Tighten all fasteners. Inspect flywheel key. Check crankshaft runout.

Reset: For electronic ignition issues, no user reset available.

Parts List & Diagrams

Reference exploded-view diagrams for part numbers and assembly order. Always use genuine Stihl parts (crankshaft seals, gaskets, bearings) to ensure longevity and performance.

Engine Group: Piston, rings, cylinder, gaskets, crankshaft assembly.
Fuel Group: Carburetor kit, fuel line, filter, tank.
Ignition Group: Ignition module, spark plug, flywheel, stop switch.
Clutch/Drive Group: Clutch assembly, drum, rim sprocket, needle bearing.
Cutting Attachment: Guide bar, chain, sprocket nose, bar nuts.

Service: For technical support and parts, contact an authorized Stihl dealer or visit www.stihlusa.com.