Stihl MS250C Owners Manual

The Stihl MS250C is a lightweight, professional-grade chainsaw featuring a powerful 45.4 cc engine with STIHL Quickstop® inertia chain brake, Ematic™ lubrication system, side-access chain tensioner, easy-start system, and anti-vibration system. Designed for demanding cutting tasks such as felling, limbing, and bucking. Below are key sections for safety, features, assembly, operation, maintenance, and troubleshooting.

Features at a Glance

Key components: 45.4 cc 2-stroke engine, STIHL Quickstop® inertia chain brake, Ematic™ lubrication system, side-access chain tensioner, decompression valve, anti-vibration system, and tool-free air filter cover.

Assembly & Preparation

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

1. Attach guide bar and chain: Ensure chain brake is disengaged, align bar, fit chain with cutters facing forward, tighten bar nuts.
2. Fill fuel tank: Use STIHL MotoMix® pre-mixed fuel or mix 50:1 with STIHL HP Ultra oil and 89+ octane gasoline.
3. Fill chain oil tank: Use STIHL chain oil or equivalent.
4. Check chain tension: Chain should be snug against bar but pull freely.

WARNING! Always wear appropriate PPE: safety glasses, hearing protection, gloves, chainsaw chaps, and sturdy boots. Never operate without proper training.

First-Time Operation

Perform pre-operation checks before starting.

1. Check chain tension and lubrication: Chain should move freely when pulled; oiler functioning.
2. Prime fuel system: Press primer bulb 5-7 times until fuel is visible.
3. Set master control lever: Move to cold start position (choke).
4. Start engine: Place on ground, hold front handle with left hand, step on rear handle, pull starter rope briskly.
5. Warm up: After engine starts, move master control to run position and allow 30 seconds warm-up.

CAUTION! Ensure clear work area, secure footing, and no bystanders within 15 feet.

Specifications

• Engine: 45.4 cc single-cylinder 2-stroke air-cooled.
• Power Output: 2.6 kW (3.5 hp).
• Fuel/Oil Mix: 50:1 (STIHL HP Ultra oil).
• Guide Bar Options: 16", 18".
• Chain Pitch/Gauge: 3/8" PMM, .050".
• Weight (powerhead): Approx. 10.8 lbs (4.9 kg).
• Sound Pressure Level: Approx. 106 dB(A).
• Vibration Levels: Front/rear handles meet ISO standards.
• Warranty: Limited warranty for personal/commercial use.

Controls and Functions

Master Control Lever: Combines choke, run, stop functions. Throttle Trigger: Controls engine speed. Throttle Trigger Lockout: Must be depressed to engage throttle. Chain Brake Lever: Manual activation; inertia-activated. Decompression Valve: Reduces starting effort. Chain Catcher: Helps reduce risk of broken chain.

Operation: Start with brake engaged; disengage by pulling front hand guard toward operator. Use proper grip: left hand on front handle, right on rear. Maintain secure footing and balance at all times.

Chain & Bar Maintenance

Regular maintenance ensures optimal performance and safety.

1. Chain sharpening: Use round file and guide; maintain 30° cutting angle, 10° top plate angle.
2. Chain tension: Check frequently when hot; adjust via side tensioner.
3. Bar maintenance: Clean bar groove, flip bar regularly for even wear.
4. Lubrication: Ensure oiler is working; adjust flow if needed.

Tip: Always stop engine and allow to cool before performing maintenance. Wear gloves when handling chain.

Engine Operation

For efficient and safe cutting.

1. Starting: Follow cold/hot start procedure using master control lever.
2. Cutting techniques: Use lower quadrant of bar for cutting; avoid tip contact to prevent kickback.
3. Fuel management: Use fresh fuel mix; empty tank for storage over 30 days.
4. Air filter: Clean regularly; replace if damaged.
5. Spark plug: Check gap (0.020"); replace if fouled.

WARNING! Never operate chainsaw above shoulder height or with one hand. Always be aware of kickback zone.

Safety Features

STIHL Quickstop® Inertia Chain Brake: Automatically stops chain in kickback event. Chain Catcher: Reduces risk from broken chain. Throttle Trigger Lockout: Prevents accidental throttle engagement. Right-Hand Guard: Protects from chain contact. Anti-Vibration System: Reduces operator fatigue.

Care & Storage

Clean after each use. Remove debris from air intake, cooling fins, and guide bar. Empty fuel tank for long-term storage. Store in dry, secure location out of reach of children.

CAUTION! Never use pressure washer; avoid water near air filter and carburetor. Store fuel in approved container away from ignition sources.

Regulatory Information

EPA and CARB compliant for emissions. Meets ANSI B175.1 safety standards. Copyright © STIHL Incorporated. All rights reserved. For genuine parts and accessories, use only STIHL-approved products. For support, visit www.stihlusa.com or contact 1-800-467-8445.

Troubleshooting

Service: For repairs, see authorized STIHL servicing dealer. Do not attempt major repairs without proper training.

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