Stihl MS171 Chainsaw Manual

The Stihl MS171 is a lightweight, easy-to-handle chainsaw designed for homeowners and occasional users. It features a powerful gasoline engine with STIHL's easy-start technology, an anti-vibration system, an Ematic™ lubrication system for reduced oil consumption, and a Quickstop® Super chain brake for enhanced safety. Below are key sections for safety, features, assembly, operation, maintenance, and troubleshooting.

Features at a Glance

Key components: Engine, guide bar, saw chain, chain brake, throttle trigger, master control lever, fuel and oil caps.

Safety Information

Read all instructions before use. Wear proper PPE: safety glasses, hearing protection, gloves, chainsaw chaps, and sturdy boots.

1. Clear work area of obstacles and bystanders.
2. Inspect chainsaw before each use: check chain tension, sharpness, and lubrication.
3. Always engage chain brake when starting or carrying the saw.
4. Use proper cutting techniques; avoid kickback zone (upper tip of guide bar).

WARNING! Chainsaws are dangerous. Failure to follow safety rules can result in serious injury or death. Never operate when tired or under the influence.

Assembly & First-Time Setup

Unpack and inspect contents. Assemble guide bar and chain.

1. Attach guide bar: Loosen nuts, position bar on studs, align chain drive links with sprocket.
2. Install chain: Place chain over bar with cutters facing forward on top. Ensure it seats in bar groove.
3. Tension chain: Adjust tensioning screw until chain fits snug against bar but can be pulled by hand.
4. Fill fuel: Use STIHL MotoMix® pre-mixed fuel or mix 50:1 with STIHL HP Ultra oil and 89+ octane gasoline.
5. Fill bar & chain oil: Use STIHL chain oil or equivalent.

CAUTION! Ensure chain brake is engaged during assembly. Tighten all fasteners securely.

Specifications

• Engine Displacement: 30.1 cc (1.84 cu. in.)
• Power Output: 1.5 kW (2.0 bhp)
• Fuel Tank Volume: 0.25 L (8.5 fl. oz.)
• Oil Tank Volume: 0.15 L (5.1 fl. oz.)
• Guide Bar Lengths: Typically 12" to 16"
• Chain Pitch/Gauge: 3/8" PMM / 0.043" (1.1 mm)
• Weight (powerhead): Approx. 3.9 kg (8.6 lbs)
• Sound Power Level: 106 dB(A)
• Vibration Levels: Left/Right: 3.2 m/s², Front/Rear: 2.5 m/s²

Controls and Components

Front Handle: Contains throttle trigger and throttle trigger lockout. Rear Handle: Contains master control lever and start/stop switch.

Master Control Lever Positions: STOP (0), START (choke) position, RUN (normal operation). Chain Brake: Engage by pushing front hand guard forward; disengage by pulling back toward rear handle. Chain Tensioning: Screw located near guide bar mount. Fuel/Oil Caps: Twist to open/close; ensure tight seal.

Fuel & Lubrication

Use only high-quality, unleaded gasoline with minimum 89 octane mixed with STIHL HP Ultra oil at 50:1 ratio, or use STIHL MotoMix® pre-mixed fuel.

1. Fuel Mixing: Pour oil into clean container first, then add gasoline. Shake well.
2. Filling: Clean area around caps. Fill fuel and oil tanks to indicated levels.
3. Chain Lubrication: Check oil flow by running saw briefly over light-colored surface; look for oil line.

Tip: Never use automotive oil, dirty gasoline, or fuel older than 30 days. Store fuel in approved container.

Starting & Operating

Starting Procedure (Cold Engine):

1. Engage chain brake (push hand guard forward).
2. Press fuel pump bulb 5-10 times until fuel is visible.
3. Set master control lever to START (choke) position.
4. Place saw on firm ground, hold rear handle with right foot, pull starter handle slowly until resistance is felt, then pull briskly.
5. After engine fires, move lever to RUN position immediately.
6. Pull starter again to start. Allow to warm up at idle for 30 seconds.

Operating: Disengage chain brake by pulling hand guard back. Squeeze throttle trigger lockout and throttle to increase speed. Use proper cutting stance and techniques.

WARNING! Always start with chain brake engaged. Keep hands away from chain during and after operation.

Chain Maintenance

Regular maintenance ensures optimal performance and safety.

1. Chain Tension: Check frequently when new; adjust via tensioning screw. Proper tension: chain snug against bar but pulls freely.
2. Sharpening: Use STIHL filing kit or round file. Maintain correct filing angle (typically 30°). File all cutters evenly.
3. Depth Gauges: File down periodically to maintain proper height relative to cutters.
4. Guide Bar: Turn bar over regularly for even wear. Clean bar groove and oil holes.

CAUTION! Wear heavy gloves when handling chain. Ensure engine is off and cool.

Cleaning & Storage

Clean after each use. Unplug spark plug boot for safety.

1. Exterior: Wipe with clean cloth. Use brush to remove sawdust from air intake, cooling fins, and guide bar area.
2. Air Filter: Remove and clean regularly. Tap out debris or wash in soapy water (if foam). Dry completely before reinstalling.
3. Storage: Empty fuel tank and run engine until it stops to prevent carburetor issues. Store in dry, secure location away from children.

CAUTION! Never use water or solvents to clean engine. Keep air filter dry before reinstallation.

Warranty Information

STIHL Limited Warranty: Covers defects in materials/workmanship for a specified period from date of retail purchase. Proof of purchase required. Does not cover normal wear, misuse, or improper maintenance. For warranty service, contact an authorized STIHL servicing dealer. For support, visit www.stihlusa.com or contact 1-800-467-8445.

Troubleshooting

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

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