Stihl Chainsaw MS250 C Manual

The Stihl MS250 C is a lightweight, professional-grade gasoline chainsaw featuring STIHL Quickstop® inertia chain brake, STIHL Ematic™ lubrication system, side-access chain tensioner, anti-vibration system, and a powerful engine for demanding cutting tasks. 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 & Stopping 7. Operating Instructions 8. Maintenance Schedule 9. Chain & Bar Care 10. Storage Guidelines 11. Troubleshooting

Features at a Glance

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

Feature	Description
Engine Displacement	45.4 cc, 2-stroke engine
Power Output	2.6 kW (3.5 bhp)
Guide Bar Lengths	16" (40 cm) or 18" (45 cm) options
Chain Brake	STIHL Quickstop® inertia-activated
Lubrication System	STIHL Ematic™ for reduced oil consumption
Chain Tensioning	Side-access, tool-free adjustment
Anti-Vibration System	Reduces operator fatigue
Fuel Tank Capacity	0.5 liters (16.9 fl. oz)
Oil Tank Capacity	0.26 liters (8.8 fl. oz)
Weight (powerhead)	5.2 kg (11.5 lbs)

Safety Information

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

Keep bystanders at least 10 feet away.
Never operate with one hand.
Ensure chain brake functions before each use.
Use proper fuel mix (50:1 STIHL HP Ultra oil).
Do not operate when fatigued or under influence.

WARNING! Chainsaw kickback can cause severe injury. Always hold saw firmly with both hands.

Assembly & Preparation

Unpack and inspect contents. Assemble guide bar and chain.

Attach guide bar: Remove bar cover nuts, position bar, align chain, replace nuts hand-tight.
Tension chain: Use side-access wheel to adjust until snug against bar bottom.
Check oil flow: Fill oil tank, run saw briefly over cardboard to verify chain lubrication.
Fuel mix: Use 89 octane minimum gasoline with STIHL HP Ultra oil at 50:1 ratio.

CAUTION! Chain must be properly tensioned—snug but able to be pulled around bar by hand.

Specifications

Engine: 45.4 cc single-cylinder 2-stroke.
Powerhead Weight: 5.2 kg (11.5 lbs).
Fuel Consumption: Approx. 560 g/kWh.
Sound Pressure Level: 106 dB(A).
Vibration Levels: Front handle 4.2 m/s², rear handle 4.8 m/s².
Ignition System: STIHL Electronic Ignition (CDI).
Carburetor: Diaphragm-type with manual choke.
Recommended Fuel: 89 octane unleaded + STIHL HP Ultra oil (50:1).
Warranty: Limited 1-year consumer warranty.

Controls and Components

Main controls: Throttle trigger, throttle trigger lockout, master control lever (choke/run/stop), chain brake lever, decompression valve, fuel primer bulb.

Components: Front handle with hand guard, rear handle, muffler, spark plug, air filter cover, chain catcher, bar cover nuts.

Master Control Positions: STOP (0) - engine off; RUN (I) - normal operation; CHOKE (⏚) - cold start. Chain Brake: Manual activation via front hand guard; inertia activation via kickback.

Starting & Stopping

Starting Procedure (Cold Engine):

Place saw on firm ground, engage chain brake.
Press decompression valve (if equipped).
Set master control to CHOKE (⏚).
Press fuel primer bulb 5-6 times.
Pull starter rope sharply until engine fires.
Move master control to RUN (I).
Pull starter rope to start.
Disengage chain brake before cutting.

Stopping: Move master control to STOP (0).

Operating Instructions

Proper cutting techniques for safety and efficiency.

Felling: Plan escape path, make notch cut, then felling cut leaving hinge.
Limbing: Stand uphill, cut from trunk outward.
Bucking: Support log, cut from top, avoid ground contact.
Kickback Prevention: Maintain firm grip, avoid upper bar tip contact.
Chain Lubrication: Check oil level frequently, adjust flow if needed.

Tip: Let saw do the work—don't force it. Keep chain sharp.

Maintenance Schedule

Daily/Before Use: Check chain tension, sharpness, brake function, air filter, fuel/oil levels.

Weekly: Clean air filter, check spark plug, clean cooling fins, inspect bar for wear.

Monthly: Clean fuel filter, check anti-vibration elements, inspect clutch drum.

Annually: Replace fuel line, inspect carburetor diaphragm, professional servicing.

WARNING! Always disconnect spark plug before maintenance.

Chain & Bar Care

Chain Sharpening: Use round file matching chain pitch (typically 3/8" P). Maintain 30° cutting angle, 10° top plate angle. File all cutters equally.

Bar Maintenance: Clean bar groove weekly, flip bar monthly for even wear, dress rails with flat file when burred.

Lubrication: Use STIHL chain oil or equivalent. Adjust oil flow screw if needed.

Storage Guidelines

Long-term storage (over 30 days):

Drain fuel tank and run carburetor dry.
Remove chain, clean and soak in oil.
Clean entire saw, especially cooling fins.
Store in dry place, cover to prevent dust.
Remove spark plug, add teaspoon of oil, pull starter slowly.

CAUTION! Never store with fuel in tank—fuel degrades and damages components.

Troubleshooting

Symptom	Possible Cause	Corrective Action
Engine won't start	Fuel, spark, compression	Check fuel mix, spark plug, decompression valve, carburetor settings.
Engine runs poorly	Air filter, fuel filter	Clean/replace air filter; check fuel filter and line.
Chain doesn't turn	Brake engaged, clutch	Disengage chain brake; check clutch springs and drum.
Excessive vibration	Loose components	Tighten all fasteners; check anti-vibration mounts.
Chain throws oil	Over-oiling	Adjust oil flow screw; check oil pump function.
Chain dulls quickly	Dirty wood, improper filing	Avoid cutting dirty wood; sharpen correctly; check bar groove.

Service: Authorized STIHL dealers only. For dealer locator: 1-800-467-8445 or www.stihlusa.com