STIHL MS 440 Parts Manual

The STIHL MS 440 is a professional-grade chainsaw known for its power, durability, and reliability. This parts manual provides detailed information on the components, assembly, and maintenance of the MS 440 model. It is intended for professional users and service technicians to ensure proper identification, ordering, and replacement of parts. Below are key sections covering identification, major assemblies, engine components, fuel system, ignition, cooling, drive train, guide bar, chain, and maintenance procedures.

1. Identification and Specifications 2. Major Assemblies Overview 3. Engine Components 4. Fuel System Parts 5. Ignition System Components 6. Cooling and Air Filtration System 7. Drive Train and Clutch Assembly 8. Guide Bar and Chain Components 9. Maintenance and Replacement Intervals 10. Safety Information 11. Parts Ordering and Support

Identification and Specifications

Key identifiers: Model number (MS 440), Serial number location (on crankcase), Engine type, Displacement, Power output, Weight.

FeatureDescription
ModelSTIHL MS 440
Engine Type2-stroke, single cylinder
Displacement70.7 cc (4.3 cu. in.)
Power Output4.4 kW (6.0 hp)
Weight (powerhead)6.6 kg (14.6 lbs) without bar and chain
Fuel Tank Capacity750 ml (25.4 fl. oz.)
Oil Tank Capacity360 ml (12.2 fl. oz.)
Ignition SystemElectronic, capacitor discharge
Chain Pitch.325" or 3/8"
Guide Bar LengthRecommended 16" to 28"

Major Assemblies Overview

Primary assemblies of the STIHL MS 440 chainsaw.

  1. Crankcase Assembly: Houses crankshaft, bearings, and seals.
  2. Cylinder and Piston Assembly: Includes cylinder, piston, rings, and wrist pin.
  3. Fuel System Assembly: Tank, carburetor, fuel lines, filter, and pump.
  4. Ignition Assembly: Flywheel, ignition module, spark plug, and stop switch.
  5. Drive Train: Clutch, sprocket, and chain brake assembly.
  6. Handlebars and Housing: Front and rear handles, anti-vibration elements, and outer housing.

WARNING! Always disconnect the spark plug before disassembling any major components to prevent accidental starting.

Engine Components

Detailed list of internal combustion engine parts.

  1. Cylinder: Part number 1128 020 1201 - with decompression valve port.
  2. Piston: Part number 1128 030 2001 - includes piston rings and wrist pin.
  3. Crankshaft: Part number 1128 040 0600 - with integrated counterweights.
  4. Connecting Rod: Part number 1128 050 2000 - connects piston to crankshaft.
  5. Crankcase: Part number 1128 080 0601 - upper and lower halves.
  6. Bearings and Seals: Main bearings (6202 C3) and crankshaft seals.

CAUTION! Use genuine STIHL parts to maintain engine performance and warranty.

Fuel System Parts

Ignition System Components

Parts responsible for generating spark to ignite fuel mixture.

Flywheel: Part number 1128 400 0601 - with magnets for ignition and cooling fan.
Ignition Module: STIHL Electronic Ignition, part number 1128 400 1201.
Spark Plug: Bosch WSR 6 F or NGK BPMR 7A, gap 0.5 mm (0.020").
Stop Switch: Part number 1128 962 0600 - grounds ignition to stop engine.
Wiring Harness: Connects switch, module, and spark plug.

Cooling and Air Filtration System

Components that keep engine temperature controlled and air clean.

  1. Turn off engine and allow to cool before servicing air filter.
  2. Remove cover screws to access air filter housing.
  3. Clean or replace foam and mesh filter elements as needed.
  4. Inspect cooling fins on cylinder for debris blockage.

Tip: A clogged air filter is a common cause of poor engine performance and overheating.

Drive Train and Clutch Assembly

Parts that transfer engine power to the chain.

  1. Clutch Drum: Part number 1128 640 0601 - holds rim sprocket.
  2. Clutch Assembly: Centrifugal type, part number 1128 160 0601.
  3. Drive Sprocket: Rim sprocket type, part number 1128 007 1003 (.325") or 1128 007 1005 (3/8").
  4. Chain Brake: Band and handle assembly, part number 1128 790 0600.
  5. Oil Pump: Automatic and manual, part number 1128 650 0600.
  6. Oil Lines: Supply line from tank to pump, part number 1128 658 0600.

WARNING! Always wear protective gloves when handling the drive sprocket and clutch due to sharp edges.

Guide Bar and Chain Components

Cutting attachment parts for the MS 440.

Guide Bar: STIHL Rollomatic E or ES, lengths 16" to 28". Part numbers vary by length and pitch.
Saw Chain: STIHL 63PM or 26RM series, .325" or 3/8" pitch. Ensure correct gauge for bar.
Bar Nuts: Part number 0000 957 1002 - M8 x 1.25.
Chain Tensioner: Part number 1128 312 0600 - includes adjustment screw and pin.
Sprocket Nose: Replaceable tip on some bar models, part number 0000 350 7505.

Maintenance and Replacement Intervals

Recommended service schedule for optimal performance and safety.

ComponentIntervalAction
Air FilterDaily or 10 hoursClean with soap/water; replace if damaged.
Spark Plug100 hoursClean, re-gap, or replace.
Fuel Filter50 hoursReplace in-tank filter.
Chain Brake25 hoursTest function; inspect band for wear.
Bar and ChainAs neededSharpen chain; rotate bar; check for wear.
Clutch and Sprocket200 hoursInspect for wear; replace rim sprocket.
Cylinder Fins25 hoursClean debris for proper cooling.

Reset: N/A for mechanical parts manual.

Safety Information

Critical safety reminders when handling parts and performing maintenance.

CAUTION! Always use proper tools. Ensure the chainsaw is secure during disassembly. Replace worn or damaged parts immediately. Follow torque specifications for all fasteners. Use only STIHL-approved replacement parts and accessories.

Parts Ordering and Support

How to identify and order genuine STIHL MS 440 parts.

  1. Locate the serial number on the crankcase.
  2. Use the illustrated parts diagrams (IPL) for accurate part identification.
  3. Contact an authorized STIHL servicing dealer with the model and part numbers.
  4. For technical support, visit www.stihlusa.com or call 1-800-467-8445.

Service: 1-800-467-8445; www.stihlusa.com

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