MS 440 STIHL Manual

The STIHL MS 440 is a professional-grade chainsaw designed for demanding forestry and arborist work. It features a powerful engine with advanced anti-vibration system, electronic ignition, quickstop chain brake, and STIHL's Ematic lubrication system. Below are key sections for safety, features, operation, maintenance, troubleshooting, and technical specifications.

Features at a Glance

Key components: Engine with decompression valve, anti-vibration system, side-access chain tensioner, quickstop inertia chain brake, and STIHL Oilomatic saw chain.

Safety Information

Read and understand all instructions before operation. Always wear proper PPE.

1. Personal Protective Equipment (PPE): Always wear chainsaw chaps, safety helmet with face shield and hearing protection, gloves, and steel-toed boots.
2. Work Area Safety: Clear work area of obstacles and bystanders. Maintain secure footing.
3. Chain Brake Check: Test chain brake function before each use.
4. Kickback Zone: Avoid contact with upper quadrant of guide bar tip.

WARNING! Chainsaw operation is inherently dangerous. Failure to follow safety instructions can result in serious injury or death.

Assembly & Preparation

Assemble guide bar and chain. Fill with fuel and oil.

1. Attach guide bar: Remove side cover, position bar over studs, ensure tensioning pin engages in bar hole.
2. Install chain: Place chain over sprocket and bar, ensure cutting teeth face forward on top of bar.
3. Tension chain: Use side-access tensioner to achieve proper tension (chain should snap back when pulled from bar).
4. Fuel mixture: Use 50:1 mixture of unleaded gasoline (min. 89 octane) and STIHL HP Ultra 2-cycle oil.
5. Chain oil: Fill oil tank with STIHL chain oil or equivalent.

CAUTION! Use only STIHL-approved fuel and oil mixtures. Improper fuel can cause engine damage.

Technical Specifications

• Engine Type: 2-stroke, single cylinder, air-cooled.
• Bore x Stroke: 50 mm x 36 mm (1.97" x 1.42").
• Idle Speed: 2,800 rpm.
• Maximum Power Speed: 9,000 rpm.
• Spark Plug: Bosch WSR 6 F or NGK BPMR 7A, gap 0.5 mm (0.020").
• Carburetor: STIHL HD-12 with fuel pump.
• Fuel/Oil Ratio: 50:1 (2% oil).
• Sound Pressure Level: 112 dB(A).
• Vibration Levels: Left/Right 4.5 m/s², Front/Rear 2.5 m/s².
• Warranty: 12 months commercial use, 24 months private use.

Controls and Components

Main controls located on rear handle and between handles.

Right Side: Throttle trigger with interlock, choke lever, master control lever (stop/run/choke), decompression valve.

Left Side: Chain brake handle, front hand guard, oil filler cap.

Rear: Fuel filler cap, rear handle with vibration damping, starter grip.

Between Handles: Throttle lockout, chain catcher, spark plug cover.

Starting & Stopping Procedure

Cold Start (with decompression valve):

1. Engage chain brake by pushing handle forward.
2. Press decompression valve (if equipped).
3. Set master control lever to choke position (full down).
4. Press throttle lockout and squeeze throttle trigger once.
5. Place saw on ground, secure with foot in rear handle.
6. Pull starter rope briskly until engine fires (1-3 pulls).
7. Move master control lever to half-throttle position (middle).
8. Pull starter rope until engine starts.
9. Briefly blip throttle to disengage fast idle.

Stopping: Release throttle, allow engine to idle, push master control lever up to STOP position.

Operation Guidelines

Proper cutting techniques for safety and efficiency.

1. Bucking: Cut from top of log whenever possible. Use supporting cuts for large logs.
2. Limbing: Stand on left side of trunk. Cut branches from bottom to top.
3. Felling: Plan escape path (45° angle to rear). Make notch cut 1/3 of tree diameter. Make felling cut 2-5 cm above notch hinge.
4. Kickback Prevention: Maintain firm grip, don't overreach, never cut with bar tip.
5. Chain Lubrication: Check oil flow by pointing bar at light surface; look for oil line.

Tip: Keep chain sharp. A dull chain increases effort and risk of kickback.

Maintenance Schedule

Regular maintenance ensures optimal performance and longevity.

Chain & Bar Care

Proper chain maintenance is critical for safe operation.

1. Sharpening: Use correct round file size (typically 5.5 mm / 7/32"). Maintain 30° cutting angle, 10° top plate angle. File all cutters to equal length.
2. Depth Gauges: Check and file depth gauges with flat file and gauge tool. Maintain 0.65 mm (0.025") below cutter top plate.
3. Bar Maintenance: Clean bar groove weekly. Flip bar monthly for even wear. Dress bar rails with flat file when burred.
4. Tension: Chain should be snug against bar but pull freely. Re-tension when chain sags from bottom of bar.

WARNING! Always wear gloves when handling chain. Disconnect spark plug wire before maintenance.

Storage Instructions

Proper storage prevents fuel system issues and corrosion.

1. Short-term (under 30 days): Fill fuel tank to prevent condensation. Run engine dry of fuel in carburetor.
2. Long-term (over 30 days): Drain all fuel from tank and carburetor. Remove chain and store in oil. Clean entire saw thoroughly.
3. Battery (if electric start): Remove battery, store in cool dry place, charge every 3 months.

CAUTION! Store in dry location away from heat sources and flammable materials.

Troubleshooting

Service: For major repairs, contact authorized STIHL servicing dealer. Use only STIHL original parts.

Technical Support: 1-800-467-8445 (USA) or visit www.stihlusa.com