STIHL MS 380 Manual

The STIHL MS 380 is a professional-grade chainsaw designed for demanding forestry and arborist work. It features a powerful engine, robust construction, advanced safety systems including a chain brake and throttle lockout, anti-vibration handles, and STIHL's Quickstop® inertia-activated chain brake. Below are key sections for safety, features, assembly, operation, maintenance, and troubleshooting.

1. Features at a Glance 2. Safety Information 3. Assembly & Preparation 4. Specifications 5. Controls and Components 6. Starting & Operation 7. Maintenance Schedule 8. Chain & Bar Care 9. Fuel & Lubrication 10. Storage 11. Troubleshooting

Features at a Glance

Key components: High-performance engine with decompression valve, anti-vibration system, Quickstop® chain brake, side-access chain tensioner, tool-free air filter cover, and STIHL Ematic™ lubrication system.

FeatureDescription
Engine Displacement64.1 cc professional engine
Power OutputHigh torque for demanding cuts
Anti-Vibration SystemReduces operator fatigue
Quickstop® Inertia Chain BrakeStops chain in milliseconds if kickback occurs
Side-Access Chain TensionerEasy chain adjustment without tools
STIHL Ematic™ SystemEfficient chain lubrication
Decompression ValveEasier starting
Throttle LockoutPrevents accidental throttle activation
Fuel Tank Capacity0.81 US qt (0.77 liter)
Oil Tank Capacity0.51 US qt (0.48 liter)

Safety Information

Read and understand all safety warnings before operation.

  1. Personal Protective Equipment (PPE): Always wear chainsaw chaps, safety glasses, hearing protection, gloves, and steel-toed boots.
  2. Kickback Zone: Avoid contact with the upper quadrant of the guide bar tip.
  3. Chain Brake: Test function before each use. Engage when carrying or moving short distances.
  4. Fuel Safety: Refuel in well-ventilated area, engine off and cool. Use STIHL MotoMix® or 50:1 mix with high-quality oil.

WARNING! Kickback can cause severe injury or death. Maintain secure footing, grip handles firmly, and never operate above shoulder height.

Assembly & Preparation

Unpack and inspect contents. Assemble on clean, stable surface.

  1. Attach guide bar and chain: Place bar on studs, loop chain over sprocket and bar with cutters facing forward, tension correctly.
  2. Fill fuel tank: Use STIHL MotoMix® or mix 50:1 with STIHL HP Ultra oil and 89+ octane gasoline.
  3. Fill oil tank: Use STIHL chainsaw bar and chain oil.
  4. Check chain tension: Chain should snap back when pulled from bar; adjust via side tensioner if loose.

CAUTION! Ensure chain brake is disengaged during assembly. Wear gloves when handling chain.

Specifications

Controls and Components

Master Control Lever: Combines stop switch, choke, and fast idle. Throttle Trigger & Lockout: Must depress lockout to activate throttle. Chain Brake Lever: Manual engagement; inertia-activated. Decompression Valve: Reduces cylinder pressure for easier starting. Side-Access Chain Tensioner: Located near guide bar mount.

Main Components: Fuel Cap, Oil Cap, Air Filter Cover, Spark Plug, Muffler, Handle, Rear Handle Guard, Chain Catcher.

Starting & Operation

Cold Start:

  1. Engage chain brake. Set Master Control to choke (full down).
  2. Press decompression valve (if equipped).
  3. Place on ground, hold rear handle with right foot, pull starter cord sharply until engine fires.
  4. Move Master Control to half-throttle position, pull until starts.
  5. Blip throttle to disengage fast idle.

Warm Start: Master Control in run position (horizontal). Do not touch throttle.

Cutting Techniques: Use full throttle when cutting. Let chain do the work; do not force. Beware of pinch points, tension/compression in wood.

Maintenance Schedule

IntervalTask
Daily/Before UseCheck chain tension, sharpness, brake function; clean air filter; inspect for damage
Every 10 HoursClean spark arrestor screen; check fuel filter
Every 20 HoursReplace air filter; clean cooling fins; check spark plug
Every 100 HoursClean carburetor; check anti-vibration elements
AnnuallyProfessional servicing recommended

Tip: Always disconnect spark plug wire before performing maintenance.

Chain & Bar Care

Sharpening: Use correct round file size for chain. Maintain 30° cutting angle, 10° top plate angle. File all cutters evenly. Depth gauges: File to 0.025" (0.65 mm) with depth gauge tool. Bar Maintenance: Clean bar groove weekly. Flip bar weekly for even wear. Lubricate sprocket tip regularly.

WARNING! Dull chain increases kickback risk and operator fatigue. Always stop engine for chain maintenance.

Fuel & Lubrication

Fuel: Use 89+ octane unleaded gasoline mixed 50:1 with STIHL HP Ultra oil. For pre-mix, use STIHL MotoMix®. Do not use fuel older than 60 days. Bar & Chain Oil: Use STIHL chainsaw oil or equivalent for temperatures above 14°F (-10°C). For colder temps, use STIHL Arctic oil. Check oil flow: Run at full throttle over light surface; should see oil line.

Storage

For storage over 30 days:

  1. Drain fuel tank and run carburetor dry.
  2. Remove chain, clean and soak in oil.
  3. Clean entire saw, especially cooling fins and air filter.
  4. Store in dry place, cover to prevent dust.
  5. Remove spark plug, add teaspoon of oil, pull starter 2-3 times, reinstall plug.

CAUTION! Never store with fuel in tank; gumming can damage carburetor.

Troubleshooting

SymptomPossible CauseCorrective Action
Engine won't startNo spark, flooded, old fuelCheck spark plug; use fresh fuel; follow correct starting procedure.
Engine runs then diesClogged fuel filter, air filter, carburetorReplace fuel filter; clean air filter; service carburetor.
Loss of powerDirty air filter, clogged spark arrestor, dull chainClean/replace air filter; clean spark arrestor; sharpen chain.
Chain won't turnBrake engaged, clutch worn, chain too tightDisengage brake; inspect clutch; adjust chain tension.
Excessive vibrationLoose components, worn AV mounts, unbalanced chainTighten all fasteners; replace AV mounts; sharpen chain evenly.
Chain throws oilOil pump set too high, wrong oil viscosityAdjust oiler (if adjustable); use correct oil for temperature.

Service: For repairs beyond basic maintenance, contact authorized STIHL servicing dealer.

STIHL Technical Support: 1-800-467-8445 | www.stihlusa.com

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