Stihl MS 250 C Manual

The Stihl MS 250 C is a lightweight, professional-grade chainsaw featuring a powerful 45.4 cc engine, STIHL Quickstop® inertia chain brake, Ematic™ lubrication system, and STIHL ErgoStart™ for easy starting. It is 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 engine, STIHL Quickstop® inertia chain brake, Ematic™ lubrication system, side-access chain tensioner, STIHL ErgoStart™, and anti-vibration system.

Feature	Description
Engine Displacement	45.4 cc, 2-stroke engine
Guide Bar Lengths	16" or 18" (depending on model)
Chain Brake	STIHL Quickstop® inertia-activated
Lubrication System	Ematic™ for efficient oil use
Starting System	STIHL ErgoStart™ for reduced pull force
Anti-Vibration	Dampens vibration for user comfort
Fuel Tank Capacity	Approx. 14.9 fl. oz. (0.44 L)
Oil Tank Capacity	Approx. 8.5 fl. oz. (0.25 L)
Weight (without bar/chain)	Approx. 10.8 lbs (4.9 kg)
Chain Pitch/Gauge	.325" / .063" (typically)

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. Clear Work Area: Ensure bystanders and pets are at least 15 feet away.
3. Kickback Awareness: Be aware of kickback zone (upper quadrant of bar tip).
4. Chain Brake Test: Test inertia brake before each use by pulling throttle trigger and pushing front hand guard forward.
5. Fuel Safety: Refuel in well-ventilated area, away from ignition sources. Use STIHL MotoMix® or 50:1 fuel/oil mix.

WARNING! Failure to follow safety instructions can result in serious injury or death. Keep hands away from moving chain.

Assembly & Preparation

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, ensure cutting teeth face forward on top of bar.
3. Tension chain: Use side-access tensioner to adjust until chain snaps back when pulled from bar.
4. Fill tanks: Add fuel mix to fuel tank and STIHL chain oil to oil tank.
5. Check controls: Ensure throttle trigger, throttle lockout, and master control lever function properly.

CAUTION! Always wear gloves when handling chain. Chain must be properly tensioned to prevent derailment.

Specifications

• Engine: 45.4 cc single-cylinder 2-stroke air-cooled.
• Power Output: 2.6 kW (3.5 bhp).
• Idle Speed: 2,800 rpm.
• Maximum Power Speed: 13,000 rpm.
• Fuel/Oil Ratio: 50:1 (STIHL 2-stroke oil).
• Sound Pressure Level: Approx. 106 dB(A).
• Vibration Level (front/rear): Approx. 4.5/2.5 m/s².
• Chain Oil: STIHL chain oil or equivalent.
• Warranty: Limited warranty for personal use.

Controls and Components

Master Control Lever: Combines choke, throttle lock, and stop functions. Throttle Trigger: Controls engine speed. Throttle Lockout: Must be depressed to engage throttle. Chain Brake/Hand Guard: Stops chain if activated. Decompression Valve: Reduces starting effort. Side-Access Chain Tensioner: For easy chain adjustment.

Maintenance Points: Air filter cover, spark plug, fuel and oil caps, muffler.

Starting & Stopping

Cold Start:

1. Set chain brake to ON (forward position).
2. Press decompression valve (if equipped).
3. Move master control lever to choke position (full down).
4. Pull starter rope until engine fires (1-2 pulls).
5. Move master control lever to half-throttle position (mid-up).
6. Pull starter rope to start. Allow to idle briefly.
7. Blip throttle to disengage fast idle.

Warm Start: Master control lever in run position (mid-up). No choke.

Stopping: Release throttle, move master control lever to STOP position.

Tip: Always engage chain brake when starting or carrying saw.

Operation & Cutting Techniques

Hold saw firmly: Left hand on front handle, right on rear. Maintain secure footing.

1. Felling: Plan escape path. Use notch and back cut techniques.
2. Limbing: Cut branches from bottom to top. Use bar as a lever.
3. Bucking: Support log. Cut from top side. Avoid pinching bar.
4. Kickback Prevention: Do not cut with bar tip. Keep saw at waist level or below.
5. Chain Lubrication: Check oil flow by pointing bar at light surface and running at full throttle; oil line should appear.

WARNING! Do not operate above shoulder height. Beware of reactive forces.

Maintenance & Cleaning

Perform daily maintenance before operation.

1. Air Filter: Clean regularly with compressed air or soapy water. Replace if damaged.
2. Spark Plug: Check gap (0.020"). Clean or replace as needed.
3. Fuel Filter: Replace annually or if clogged.
4. Muffler: Remove and clean spark arrestor screen.
5. Exterior: Wipe with damp cloth. Keep cooling fins clean.

CAUTION! Disconnect spark plug wire before performing maintenance. Use only STIHL-approved parts.

Chain & Bar Care

Proper chain maintenance ensures performance and safety.

1. Sharpening: Use round file (typically 5/32" or 3/16") and file guide. Maintain 30° cutting angle.
2. Depth Gauges: File down to proper height (use depth gauge tool).
3. Bar Maintenance: Clean bar groove. Flip bar weekly for even wear.
4. Tension: Check frequently when chain is warm. Adjust so chain snaps back.
5. Lubrication: Always use proper chain oil. Check oiler output.

Tip: A sharp chain reduces effort and kickback risk.

Storage

For storage over 30 days:

1. Drain fuel tank and run engine until it stops.
2. Remove spark plug, add 1 tsp of oil through spark plug hole, pull starter 2-3 times, reinstall plug.
3. Clean entire saw, especially air filter and cooling fins.
4. Loosen chain tension. Store in dry, cool place.
5. Remove battery (if electric start model).

CAUTION! Never store with fuel in tank for extended periods. Use fuel stabilizer if necessary.

Troubleshooting

Symptom	Possible Cause	Corrective Action
Engine won't start	No spark, flooded, old fuel	Check spark plug; use fresh fuel; follow starting procedure.
Engine runs poorly	Dirty air filter, clogged fuel filter	Clean/replace air filter; replace fuel filter.
Chain doesn't turn	Chain brake engaged, low oil, worn sprocket	Disengage brake; check oiler; inspect clutch/sprocket.
Excessive vibration	Loose parts, unbalanced chain	Tighten all fasteners; sharpen chain evenly.
Chain throws oil	Over-oiling, wrong oil viscosity	Adjust oiler (if adjustable); use correct oil.
Chain dulls quickly	Cutting dirty wood, improper filing	Avoid ground contact; sharpen correctly.

Service: For repairs, contact authorized STIHL servicing dealer.

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