STIHL 021, 023, 025 Chainsaw Service & Repair Manual (P/N 1123 020 1219)

• 216-page PDF bundle: 52-page STIHL 021/023/025 service manual (©2000); 58-page STIHL 021/023/025 1123-series spare parts list dated 07/2004; 48-page STIHL 024 1121-series spare parts list dated 07/2004; and a second, identical 58-page copy of the 1123 parts list.
• Engine repair coverage follows crankcase pressure and vacuum testing, oil-seal replacement without a full teardown, engine removal and installation, cylinder and piston service, piston-ring replacement, and crankshaft and bearing work.
• Clutch, drive, and chain-brake procedures address clutch drum and sprocket inspection, chain-brake function checks and internal service, plus front, side, and quick chain-tensioner configurations.
• Fuel and ignition sections cover carburetor leakage testing and removal, configuration-specific adjustment, tank-vent testing, fuel-line and manual-pump routing, ignition lead and module service, module air-gap setup, and flywheel removal and installation.
• Oil, starter, and handle-system work spans the pickup body, tank vent, drive worm and oil pump, rewind spring replacement and tensioning, AV buffers, handle housing, Master Control switch shaft, and throttle interlock.
• Illustrated parts plates identify the model-specific shortblocks, quick chain tensioner, oil pump, chain brake, ignition system, and carburetor groups, with factory part numbers for standard, Easy Start, and regional configurations.
• Shop reference data provides model specifications, component-specific torque tables, leakage and adjustment data, wear limits, servicing aids, and an application-based special-tool list.

Repair Scope and Model Differences

The 021, 023, and 025 share the same basic design, while the manual calls out the 023 L, Easy Start equipment, U.S. carburetor arrangements, and quick-chain-adjuster hardware where procedures differ. STIHL identifies the repair material as dealer service information; its depth and dependence on pressure/vacuum testers, a tachometer, torque wrenches, and model-specific fixtures make it best suited to trained small-engine technicians.

Two serial breaks matter before internal parts are ordered. On the 021 through serial number X 34 944 402, the connecting rod and its cylindrical rollers are serviceable separately; from X 34 944 403, the rod, crankshaft, and needle bearing form an inseparable assembly. The chain-brake mechanism also changes at X 28 310 254/255, with the earlier cam-lever and spring arrangement replaced by a flat-spring design.

The ©2000 and 07/2004 dates identify the documents, not a stated 2000–2004 model-year range. The 024 material is a parts-reference section only; the repair procedures apply to the 021, 023/023 L, and 025.

Carburetion, Ignition, and Test Coverage

Carburetor coverage is configuration-specific. Standard non-U.S. models other than the 023 L receive H, L, and idle adjustment guidance, while the 023 L and U.S. versions use a fixed high-speed jet and permit only limited idle correction. The repair manual also documents carburetor leakage testing, crankcase pressure and vacuum tests, fuel-tank vent checks, ignition spark evaluation, and the limits of workshop testing for the electronic ignition module.

Full assembly-by-assembly fault charts are not contained in this PDF. The manual repeatedly refers those charts, along with several standardized component procedures, to STIHL’s separate Standard Repairs, Troubleshooting handbook. That distinction matters if the purchase is intended primarily for symptom-based fault isolation.

Parts Identification and Special Tools

The 1123-series parts list separates WT-215/WT-286, WT-283C/WT-498A/WT-503/WT-313 USA, 023 L WT-360/WT-396, and C1Q-S11G carburetor assemblies. It also distinguishes 021, 023/023 L, and 025 shortblocks, Easy Start cylinders and handle housings, regional muffler equipment, air-filter versions, and quick-tensioner parts.

The tool table identifies equipment by both function and part number. Examples include carburetor/crankcase tester 1106 850 2905, oil-seal puller 5910 890 4400 with press sleeve 1123 893 2400, ignition setting gauge 1111 890 6400, and oil-pump installing tool 1123 890 2201. Lubricant and sealant applications are listed separately.

Two repair cautions are especially specific to this platform. Driving a DG screw into a new path in a polymer or light-alloy housing cuts a second thread and weakens the joint. On a quick-chain-adjuster housing, removing the rear guide-bar collar screw too quickly can damage the housing threads.

Fuel work, live engine and chain-brake checks, spring-loaded starter and brake parts, and high-voltage ignition service carry serious hazards. Follow the manual and the saw’s safety instructions, use the specified holding and test equipment, and leave dealer-level repairs to qualified personnel.