1994–2004 Stihl FS 36, FS 40 & FS 44 Brushcutter Service Manual with Parts List

This STIHL service manual covers FS 36, FS 40, and FS 44 brushcutters, accompanied by an illustrated parts list for the 4130 series with FS 44 R variant references.

• Engine repair: Cylinder and piston replacement, crankshaft and bearing service, oil seal replacement, and crankcase pressure and vacuum testing.

• Fuel system: Diaphragm-carburetor overhaul, leakage testing and adjustment, plus fuel-pump, pickup-body, fuel-hose, air-filter and tank-vent service.

• Ignition diagnosis: Breakerless magneto troubleshooting, ignition-module and flywheel checks, spark-plug assessment, and short-circuit wire and stop-switch service.

• Starter and clutch: Starter-rope, rewind-spring and pawl replacement, clutch disassembly and assembly, and component-specific tightening specifications.

• Controls and cutting-tool drive: Handle supports, throttle cables, loop handles, two-handed handlebars, AV mounts, bearing housings, FS 44 gearhead repair and deflector shields.

• Parts identification: Numbered exploded views and part-number tables distinguish carburetor versions, drive-tube assemblies and earlier gearheads.

The manual is intended for STIHL servicing dealers and staff, with procedures requiring dedicated pressing tools and leakage-test equipment.

Engine Repair and Crankcase Leak Diagnosis

The engine section covers cylinder and piston removal, piston-ring replacement, crankshaft removal, and crankcase bearing and oil seal installation. The piston and connecting rod form an assembly; replacement cylinders are supplied with a matching piston.

Separate vacuum tests for the intake diaphragm and crankshaft oil seal help distinguish causes of rough running and unstable idle. The oil-seal test addresses leakage that may remain undetected under positive pressure. Tool references include carburetor/crankcase tester 1106 850 2905 and vacuum pump 0000 850 3500.

Carburetor Service and Variant Identification

The carburetor chapter covers metering and pump diaphragms, the inlet needle and control lever, valve jet, control valve, and throttle and choke shafts. Adjustment guidance includes high- and low-speed baseline settings and altitude corrections.

The parts list provides separate WT-160B, WT-492A (USA), and WT-327 (USA) exploded views and parts tables. These identify the named variants; the repair procedures are presented in the main diaphragm-carburetor section.

The adjustment discussion explains how an overly lean high-speed setting can damage the engine through overheating and insufficient lubrication.

Ignition Troubleshooting and Rewind Starter Repair

The ignition section explains fixed, nonadjustable timing and operational checks of the ignition module. Its troubleshooting flowchart links spark-test results to ignition and fuel-system faults; accompanying illustrations show FS 44 short-circuit wire routing and control-handle connections.

Starter procedures distinguish rope replacement with the fan housing installed from rope-rotor removal and spring replacement. Excessive rewind-spring tension can break the spring.

Ignition work involves high voltage; servicing should be performed or reviewed by a qualified technician.

Bearing Housings, Gearheads and Handle Assemblies

The cutting-tool drive section distinguishes FS 36 flanged plain bearings, FS 40 needle bearings, and the FS 44 bevel-gear head. Gearhead servicing covers bearing and pinion assembly and lubrication; the drive pinion and bevel gear are supplied as a matched set.

AV-system repair applies to FS 40 and FS 44. The drive-shaft section explains that a faulty flexible liner requires replacement of the complete drive tube.

The appended catalog includes Crankcase/Cylinder, Ignition System/Rewind Starter, and Gear Head FS 44 illustrations. Model references and earlier-design entries support component identification before parts are selected.

A Preview of Fastener Torques and Carburetor Test Data

These examples are a small selection of the manual's fastening and leakage-test specifications.

For the covered brushcutters, the torque tables specify 14 Nm (10.3 lbf.ft) for cylinder-to-crankcase fastening and 17 Nm (12.5 lbf.ft) for the clutch-to-crankshaft connection. The tables also address fasteners used in light-alloy and reinforced-polymer components.

The fuel-system specifications give 0.8 bar (11.6 psi) gauge pressure for carburetor leakage testing.

Searchable PDF and Included Parts Catalog

Text search and bookmarks: Text search is available in both sections. Embedded bookmarks provide detailed service-manual navigation and a single entry to the parts list.

One printable, 118-page PDF combines a 72-page English service manual with a 46-page parts list dated July 2004, with German, English and French parts descriptions. The parts-list cover/contents page and final symbol-key page are already included in those totals.