Stihl Chainsaw MS250 C Manual

The Stihl MS250 C is a lightweight, professional-grade chainsaw featuring a 45.4 cc engine, STIHL Quickstop® inertia chain brake, Ematic™ lubrication system, side-access chain tensioner, and STIHL Easy2Start™ system. It is designed for demanding cutting tasks including 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 engine, STIHL Quickstop® inertia chain brake, Ematic™ lubrication system, side-access chain tensioner, STIHL Easy2Start™, and anti-vibration system.

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 sturdy boots.
2. Chain Brake Check: Test the inertia chain brake before each use.
3. Clear Work Area: Ensure no bystanders, pets, or obstacles within 15 feet.
4. Fuel Safety: Refuel in a well-ventilated area, away from ignition sources. Use STIHL MotoMix® or 50:1 fuel/oil mix.
5. Kickback Zone: Avoid contact with the upper quarter of the guide bar tip.

WARNING! Failure to follow safety instructions can result in serious injury or death. Never operate a chainsaw while fatigued or under the influence.

Assembly & Preparation

Unpack and inspect contents. Assemble guide bar and chain.

1. Attach Guide Bar & Chain: Remove bar nuts and cover. Fit chain onto bar with cutters facing forward. Place bar onto studs, ensuring chain engages sprocket. Replace cover and hand-tighten nuts.
2. Tension Chain: Use side-access tensioner screw. Lift bar tip up, tighten until chain fits snugly against bar but can be pulled by hand. Retighten bar nuts.
3. Fill Fuel & Oil: Use approved 2-stroke engine oil mixed 50:1 with unleaded gasoline (min. 89 octane) or STIHL MotoMix®. Fill chain oil tank with STIHL chain oil.
4. Check Controls: Ensure throttle trigger, throttle lockout, and chain brake function properly.

CAUTION! Always wear protective gloves when handling the chain. Ensure chain is properly tensioned before starting.

Specifications

• Engine: 45.4 cc single-cylinder 2-stroke air-cooled engine.
• Power Output: 2.6 kW (3.5 bhp).
• Fuel/Oil Ratio: 50:1 (STIHL 2-stroke oil).
• Ignition System: Electronic, capacitor discharge.
• Chain Pitch/Gauge: 3/8" PMM3 (Picco Micro Mini 3) / .050".
• Sound Pressure Level: Approx. 106 dB(A).
• Vibration Levels: Front/Rear handle: Approx. 4.5/2.5 m/s².
• Warranty: Limited warranty for personal use. See dealer for details.

Controls and Components

Main Controls: Front Handle with hand guard, Rear Handle, Throttle Trigger, Throttle Lockout, Master Control Lever (combines choke, stop control, and run positions), Chain Brake lever, and Decompression Valve.

Master Control Lever Positions: - STOP (0): Engine off. - RUN (I): Normal operation. - CHOKE (⏺): Cold start position. - START (⏺ with arrow): For Easy2Start™ engagement.

Other Features: Side-access chain tensioner, Chain catcher, Right-hand guard, and Spark arrestor muffler (standard).

Starting & Stopping

Starting (Cold Engine with Easy2Start™):

1. Engage chain brake by pushing lever forward until it clicks.
2. Press decompression valve (if equipped).
3. Set Master Control Lever to CHOKE (⏺).
4. Press the primer bulb 5-10 times until fuel is visible.
5. Place saw on firm ground. Hold rear handle with right foot, grip front handle with left hand. Pull starter handle slowly until resistance is felt, then pull briskly. Engine should start after 1-3 pulls.
6. Immediately move Master Control Lever to RUN (I).

Stopping: Release throttle, let engine idle. Move Master Control Lever to STOP (0).

Tip: Always engage the chain brake when starting, carrying, or not actively cutting.

Operating Instructions

Proper cutting techniques for safety and efficiency.

1. Felling (Cutting down a tree): Plan escape path (45° behind tree). Make notch cut (1/3 tree diameter). Make felling cut, leaving hinge wood. Use wedges if needed.
2. Limbing (Removing branches): Stand uphill. Cut from trunk outward. Use top of bar for downward cuts, bottom for upward cuts.
3. Bucking (Cutting logs): Support log. Cut from top, avoid pinching bar. Use undercut if needed.
4. General: Maintain firm grip, stand with balanced stance. Let the chain do the work; do not force the saw. Keep chain sharp and properly lubricated.

WARNING! Beware of kickback. Never cut with the upper quarter of the bar tip. Always hold saw with both hands.

Maintenance Schedule

Regular maintenance ensures optimal performance and longevity.

CAUTION! Disconnect spark plug wire before performing any maintenance.

Chain & Bar Care

Proper care extends life of cutting components.

1. Sharpening: Use correct round file size (typically 4.0 mm). Maintain 30° filing angle. File all cutters evenly. Check depth gauges with gauge tool.
2. Lubrication: Always use STIHL chain oil. Check oil flow by running saw briefly over light-colored surface; oil line should appear.
3. Bar Maintenance: Clean bar groove regularly. Flip bar weekly for even wear. Dress bar rails with flat file if burred.
4. Tension: Chain should be snug but pull freely by hand. Re-tension when chain sags (check frequently when new).

Storage

Prepare saw for storage to prevent fuel system issues.

1. Drain fuel tank and run engine until it stops to clear carburetor.
2. Remove chain, clean, and soak in oil. Clean guide bar and coat with oil.
3. Clean entire saw, especially cooling fins and air filter.
4. Store in a dry, secure place, out of reach of children.

CAUTION! Never store saw with fuel in the tank for more than 30 days. Use fuel stabilizer if necessary.

Troubleshooting

Service: For repairs not covered in this manual, contact an authorized STIHL servicing dealer. Use only STIHL replacement parts.

Support: Visit www.stihlusa.com or contact STIHL customer service.