STIHL MS 441 Parts Manual

The STIHL MS 441 is a professional-grade chainsaw featuring a powerful engine, advanced anti-vibration system, and STIHL QuickStop® inertia chain brake. This parts manual provides detailed diagrams, part numbers, and ordering information for maintenance and repair. Below are key sections covering safety, engine components, cutting attachments, fuel system, ignition, and assembly instructions.

Features at a Glance

Key components: Cylinder, piston, crankshaft, carburetor, ignition module, fuel tank, oil tank, chain brake, guide bar, and cutting chain.

Feature	Description
Engine Displacement	70.7 cc (4.3 cu. in.)
Power Output	4.4 kW (6.0 bhp)
Fuel Tank Volume	0.73 L (24.7 fl. oz.)
Oil Tank Volume	0.36 L (12.2 fl. oz.)
Weight (powerhead)	6.6 kg (14.6 lbs)
Guide Bar Lengths	16" to 25" (40 cm to 63 cm)
Ignition System	Electronic, capacitor discharge
Anti-Vibration	STIHL Advanced AV System
Chain Brake	STIHL QuickStop® Inertia
Carburetor	STIHL HD-12

Safety Information

Always wear protective equipment. Disconnect spark plug before servicing.

1. Use STIHL-approved parts only for repairs.
2. Ensure chainsaw is cool before disassembly.
3. Follow torque specifications during reassembly.
4. Dispose of used parts and fluids according to local regulations.

WARNING! Failure to use genuine STIHL parts may void warranty and compromise safety. Always refer to the service manual for detailed procedures.

Engine Components

Cylinder, piston, crankshaft, connecting rod, bearings, seals.

1. Cylinder Assembly: Includes cylinder, decompression valve, spark plug.
2. Piston Assembly: Piston, rings, wrist pin, circlips.
3. Crankshaft Assembly: Crankshaft, main bearings, seals.
4. Crankcase: Upper and lower halves, gaskets.

CAUTION! Handle piston and cylinder with care to avoid scratching surfaces. Lubricate bearings during assembly.

Cutting Attachment Parts

• Guide Bar: STIHL Rollomatic® E, lengths 16" to 25".
• Cutting Chain: STIHL Oilomatic® chains (3/8" pitch, .063" gauge).
• Sprocket: Rim sprocket or spur sprocket assembly.
• Clutch: Centrifugal clutch, drum, springs.
• Chain Tensioner: Front tensioner with adjustment screw.
• Bar Nuts: M8 nuts and washers for bar mounting.
• Chain Catcher: Prevents broken chain from striking operator.
• Bumper Spike: For securing saw during cutting.

Fuel System Parts

Fuel tank, cap, filter, lines, carburetor, primer bulb.

Carburetor: STIHL HD-12 with adjustment screws (H, L, LA). Fuel Lines: Supply and return lines. Fuel Filter: In-tank filter. Air Filter: Two-stage foam and felt element.

Maintenance: Replace fuel filter annually; clean air filter regularly; inspect fuel lines for cracks.

Ignition System Parts

Ignition module, spark plug, stop switch, wiring harness.

1. Disconnect spark plug wire before servicing ignition.
2. Check module air gap (0.3 mm / 0.012 in).
3. Use specified spark plug: Bosch WSR6F or equivalent.

Tip: Test ignition with a spark tester; replace module if no spark.

Anti-Vibration System

AV buffers, springs, and mounts reduce vibration to handles.

1. Front AV Mounts: Rubber buffers at engine front.
2. Rear AV Mounts: Springs and buffers at rear handle.
3. Inspect for wear: Replace if cracked or deformed.
4. Reassemble with proper alignment to maintain effectiveness.

WARNING! Worn AV components increase vibration and operator fatigue. Replace as a set.

Assembly Instructions

Follow sequence for engine reassembly and component installation.

1. Crankcase Assembly: Install crankshaft, bearings, seals; apply sealant to case halves.
2. Piston/Cylinder: Install piston on rod, align ring gaps; slide cylinder over piston.
3. Carburetor/Fuel System: Mount carburetor, connect fuel lines, install air filter.
4. Ignition: Set module gap, mount module, connect stop switch.
5. AV System: Install buffers and springs before attaching handles.
6. Cutting Attachment: Install clutch, sprocket, bar, chain; adjust tension.

CAUTION! Use torque wrench; do not overtighten fasteners.

Torque Specifications

Critical fasteners and their torque values.

Component	Torque	Notes
Cylinder bolts	10 Nm (88 in-lb)	Apply in crisscross pattern
Clutch nut	40 Nm (30 ft-lb)	Left-hand thread
Flywheel nut	40 Nm (30 ft-lb)	Use holder tool
Guide bar nuts	10 Nm (88 in-lb)	Even tension
Spark plug	25 Nm (18 ft-lb)	Do not overtighten
Muffler bolts	8 Nm (71 in-lb)	Replace gasket

Exploded Diagrams

Refer to diagrams for part identification and assembly order.

Diagram 1: Engine Assembly (crankshaft, piston, cylinder). Diagram 2: Fuel System (tank, carburetor, lines). Diagram 3: Ignition System (module, coil, wiring). Diagram 4: Cutting Attachment (clutch, bar, chain). Diagram 5: Anti-Vibration System (buffers, springs).

Note: Part numbers correspond to STIHL genuine parts catalog.

Troubleshooting & Part Replacement

Symptom	Possible Cause	Part Replacement
Engine won't start	Ignition module, spark plug	Replace spark plug; test and replace ignition module if faulty.
Loss of power	Piston/cylinder wear, clogged muffler	Inspect cylinder scoring; replace piston/cylinder set; clean/replace muffler.
Oil leakage	Crankcase seals, gaskets	Replace crankshaft seals and crankcase gaskets.
Excessive vibration	Worn AV buffers	Replace front and rear AV buffer sets.
Chain won't oil	Oil pump, lines, bar groove	Replace oil pump; clean/replace oil lines; check bar oil hole.

Ordering Parts: Use STIHL part numbers from diagrams. Contact authorized STIHL dealer.

Support: STIHL Incorporated, 1-800-467-8445; www.stihlusa.com