The Stihl MS250 is a lightweight, professional-grade chainsaw designed for demanding cutting tasks. This parts manual provides detailed diagrams, part numbers, and ordering information for all components of the MS250 chainsaw, including the engine assembly, cutting attachment, fuel system, ignition system, air filtration, anti-vibration system, and clutch assembly. Below are key sections for identification, engine parts, cutting equipment, maintenance parts, and ordering.
Identify your MS250 using the serial number plate on the rear handle. Key specifications for parts ordering.
| Component | Specification / Part Number Reference |
|---|---|
| Engine Type | STIHL 2-MIX engine, single cylinder, 2-stroke |
| Displacement | 45.4 cm³ (2.77 cu. in.) |
| Power Output | 2.6 kW (3.5 bhp) |
| Fuel Tank Volume | 0.47 L (0.12 US gal) |
| Oil Tank Volume | 0.26 L (0.07 US gal) |
| Guide Bar Mounting | STIHL 3005 mount |
| Recommended Bar Lengths | 40 cm (16"), 45 cm (18") |
| Chain Pitch | 3/8" PMM3 (Picco Micro Mini 3) |
| Ignition System | Electronic, capacitor discharge (CDI) |
| Weight (powerhead) | 5.2 kg (11.5 lbs) |
Cylinder, piston, crankshaft, bearings, seals, and associated components.
WARNING! Engine disassembly requires specialized tools and knowledge. Refer to service manual for procedures.
Guide bar, saw chain, chain tensioner, bar nuts, and clutch cover parts.
CAUTION! Always match chain pitch and gauge to the guide bar. Use only STIHL recommended combinations.
Fuel tank, carburetor, fuel lines, filter, and pump diaphragm parts.
Carburetor: Zama C1Q-S series. Parts include: throttle/choke shafts, diaphragms (pump & metering), gaskets, inlet needle, jets, and adjustment screws.
Fuel System: Fuel tank, cap, filter, impulse line, and fuel pickup line. Primer bulb assembly (if equipped).
Air filter, cover, pre-cleaner, and intake parts.
Tip: Clean air filter regularly with warm water and mild detergent. Allow to dry completely before reinstalling.
Supports STIHL anti-vibration system with spring/damper elements.
WARNING! Damaged AV mounts increase vibration. Replace in sets to maintain balance.
Centrifugal clutch, drum, sprocket, and chain brake band/spring.
| Part | Function | Notes |
|---|---|---|
| Clutch Drum | Holds rim sprocket, guides chain | Check for groove wear |
| Centrifugal Clutch | Engages chain at high RPM | Replace shoes as a set |
| Rim Sprocket | Drives the chain | 7-tooth standard; replace when worn |
| Chain Brake Band | Stops chain during kickback | Inspect for wear and heat discoloration |
| Brake Spring | Returns brake to disengaged position | Replace if brake feels weak |
Common wear items: spark plug, air filter, fuel filter, chain, guide bar, sprocket.
Maintenance Kits: Available kits may include air filter, spark plug, and fuel filter.
Lubrication: Bar and chain oil (STIHL ForestPlus or similar). Grease for sprocket nose (if applicable).
Always wear PPE. Use correct fuel/oil mix (50:1 with STIHL HP Ultra oil). Ensure chain brake functions before each use. Keep chain sharp and properly tensioned.
CAUTION! Use only original STIHL parts or approved equivalents to maintain safety, performance, and warranty.
| Symptom / Need | Required Information | Action |
|---|---|---|
| Ordering a specific part | Part number from diagram, saw serial number | Contact authorized STIHL dealer with part number. |
| Identifying a part | Reference exploded view diagram in this manual | Match component to numbered diagram. |
| Warranty claim | Proof of purchase, serial number | Present to selling dealer. |
| Technical support | Model (MS250), serial number, symptom | Call STIHL customer service or visit dealer. |
| Manual download | N/A | Visit STIHL USA website support section. |
Support: Contact your local authorized STIHL dealer. For dealer locator or information: www.stihlusa.com