STIHL 029/039 Chainsaw Service & Parts Manual Set

The exploded views identify installed component positions alongside the service procedures. STIHL states that the two saws share nearly the same design and that model-specific differences are identified where they matter.

The service manual refers to separate Technical Information bulletins for engineering changes introduced after publication; those bulletins are not included in this download.

Searchable PDFs and Service-Manual Bookmarks

Text search and diagram detail: Both PDFs support text search. The service manual has chapter and subsection bookmarks; the parts list has an index but no embedded bookmarks. Enlarging the automatic-choke schematic makes its small legend easier to read.

ZIP download containing two printable English PDFs, 96 pages total. That total includes the service manual’s title/introduction and contents pages and the parts list’s index page.

Engine, Cutting Drive, and Fuel-System Service

This selected content overview is not a complete table of contents. Other topics include front-to-side chain-tensioner conversion and sleeve modification for the piston snap-ring installing tool.

• Engine repair: Exhaust and spark-arrestor service, pressure and vacuum leak testing, oil-seal replacement, engine removal, and internal work on the cylinder, piston, rings, crankshaft, bearings, and engine pan.

• Clutch and cutting drive: Clutch drum, spur and rim sprockets, centrifugal clutch, chain-brake disassembly and assembly, front and side chain tensioners, and bar-mounting studs.

• Ignition, starter, and controls: Spark fault isolation, ignition-module replacement and air-gap setting, flywheel removal, stop-circuit wiring, starter rope and rewind-spring service, and Master Control repairs.

• Fuel-system diagnosis and repair: Carburetor removal, leak testing, internal service and adjustment, tank ventilation, fuel pickup and hose work, plus automatic-choke component testing.

• Troubleshooting charts: Six system charts address the engine, ignition, fuel delivery, rewind starter, chain lubrication, and clutch/chain-brake drive. A separate automatic-choke flowchart supports fault isolation.

• Illustrated parts identification: Twelve exploded assembly views provide reference numbers, quantities, and part numbers for the cylinder groups, engine housing, oil pump and clutch, chain brake, ignition, starter, handle housing, carburetors, and tools.

Written for STIHL servicing dealers and staff, this material assumes workshop experience and access to the specified measuring and service tools.

Engine Assemblies and Housing Repairs

The engine chapter explains the saw’s nonconventional crankcase arrangement, in which the cylinder, piston, crankshaft, and engine pan form the power unit. Step-by-step procedures document cylinder-to-pan sealing, correct crankshaft and piston orientation, and ring installation.

Replacement assemblies: The crankshaft is replaced as a complete connecting-rod and needle-bearing assembly. Replacement cylinders are supplied with their corresponding pistons. Low-compression machines carrying an “N” suffix require the matching special piston.

Repair coverage extends beyond the powerhead. Separate chapters deal with the AV buffer system, front and handle housings, throttle interlock, switch shaft, and one-piece fuel-tank/engine-housing replacement.

Chain lubrication: The adjustable oil-pump section covers removal and internal service, including the pump piston, control bolt, springs, and seals. Related procedures address the suction hose, pickup body, and oil-tank vent.

Component-specific torque tables, leak-test specifications, ignition settings, carburetor data, cutting-attachment specifications, capacities, and approved service aids are included.

Carburetors and Automatic-Choke Diagnosis

The service manual explains the shared Zama/Walbro diaphragm-carburetor construction and identifies differences where individual parts or assembly details change. The companion parts list distinguishes HD-19B, HD-18B for the US-market 029, HD-21B for the US-market 039, and HD-5 configurations, including fixed-jet and high-altitude parts.

Automatic-choke coverage includes operating theory, temperature-dependent action, the control valve, bellows, foam and sintered filters, hose connections, and carburetor linkage. It documents leak checks and removed-component tests as well as inspection of the installed system.

Diagnostic illustrations: The Automatic Choke schematic and Ignition System troubleshooting flowchart are supported by Pressure Test and Vacuum Test setup illustrations. Chain Brake assembly views and the Oil Pump, Clutch exploded illustration show component relationships.

This is not a full wiring-diagram publication; electrical repair is limited to the breakerless magneto ignition, stop circuit, related wiring, and their diagnostic chart.

Parts Changes, Service Tools, and Repair Cautions

The parts list flags a 029 piston/ring change at machine-number notation X 39 305 257 (46.97), a US muffler change at X 39 304 256, dated component revisions, and Brazil-, USA-, Australia-, and Canada-specific parts. These distinctions help prevent ordering from the wrong exploded view or carburetor group.

Leak-testing equipment: The service-tool table gives applications and STIHL part numbers, including carburetor/crankcase tester 1106 850 2905 and vacuum pump 0000 850 3500.

Other specified tools include ignition setting gauge 1127 890 6400, piston-ring clamping strap 1127 893 2600, and clutch-spring assembly hook 5910 890 2800.

The clutch uses a left-hand thread, and STIHL warns that substituting another piston stop for the specified locking strip can damage the piston. The DG fasteners form permanent threads in polymer and light-alloy parts; starting one on a new path instead of the existing thread can damage the housing.

Ignition high voltage, fuel handling, the tensioned chain-brake and rewind springs, and sharp cutting components require normal professional workshop precautions.

Preview: Ignition Air Gap and Bellows Leak-Test Data

For ignition-module installation, the manual specifies a 0.15–0.3 mm air gap between the flywheel and ignition module, with a dedicated setting gauge listed for that job.

For automatic-choke diagnosis, the bellows leakage test uses approximately 0.1 bar (1.45 psi), with pressure remaining constant for one minute. The section covers testing with the bellows removed or still installed.