The Stihl MS 170 is a lightweight, easy-to-handle chainsaw designed for occasional users and homeowners. This parts manual provides detailed information on the components, assembly, maintenance, and replacement parts for the MS 170 model. Below are key sections covering identification, major assemblies, individual parts, maintenance procedures, and ordering information.
Key identification: Model number MS 170, serial number location on crankcase. Engine type: Single-cylinder, two-stroke, air-cooled.
| Feature | Description |
|---|---|
| Displacement | 30.1 cc (1.84 cu. in.) |
| Power Output | 1.5 kW (2.0 hp) |
| Fuel Tank Volume | 250 ml (8.5 fl. oz.) |
| Oil Tank Volume | 145 ml (4.9 fl. oz.) |
| Guide Bar Lengths | 30 cm (12"), 35 cm (14"), 40 cm (16") |
| Chain Pitch | 3/8" PMM (Picco Micro Mini) |
| Weight (powerhead) | 3.9 kg (8.6 lbs) |
| Ignition System | Electronic, capacitor discharge |
| Carburetor | Diaphragm type, fixed-jet |
| Vibration Damping | Standard |
Main assemblies: Engine unit, cutting attachment, handle system, fuel system.
WARNING! Always disconnect the spark plug boot before working on any parts to prevent accidental starting.
Cylinder, piston, crankshaft, connecting rod, bearings, seals.
CAUTION! Use only genuine Stihl parts to ensure proper fit and performance.
Front handle with vibration damping, rear handle with fuel/oil tank.
Front Handle: Part number 1128 790 0601. Rear Handle: Part number 1128 430 0601. Throttle Trigger: Part number 1128 716 0600. Throttle Lockout: Part number 1128 716 0601. Master Control Lever: Part number 1128 718 0600 (combines choke, stop, run). Hand Guard: Part number 1128 790 0602.
Fuel tank, oil tank, caps, filters, lines.
Tip: Use only clean, fresh fuel mix (50:1 gasoline to Stihl HP Ultra oil) and Stihl chain oil.
Regular maintenance ensures longevity and safety.
WARNING! Wear protective gloves when handling sharp chain and bar.
Critical fasteners must be tightened to specified torque.
| Part | Torque | Thread |
|---|---|---|
| Cylinder bolts | 10 Nm (88 in.lb) | M6 |
| Clutch nut | 35 Nm (26 ft.lb) | M12x1.25 left-hand |
| Flywheel nut | 40 Nm (30 ft.lb) | M12x1.25 |
| Spark plug | 25 Nm (18 ft.lb) | M14x1.25 |
| Guide bar nuts | 8-10 Nm (71-88 in.lb) | M6 |
| Handle bolts | 8 Nm (71 in.lb) | M6 |
Always follow safety instructions in the operator's manual. Use proper personal protective equipment (PPE).
CAUTION! Use only original Stihl replacement parts to maintain safety certifications.
Order parts through authorized Stihl dealers. Provide model number (MS 170) and serial number. Use the illustrated parts list (IPL) for accurate part identification. Common part numbers listed in this manual. For warranty claims, proof of purchase and serial number required.
| Symptom | Possible Part Issue | Corrective Action |
|---|---|---|
| Engine won't start | Spark plug, fuel filter, carburetor | Check/replace spark plug; clean/replace fuel filter; inspect carburetor diaphragm. |
| Chain doesn't turn | Clutch, sprocket, drive spring | Inspect clutch shoes for wear; check sprocket; replace drive spring if broken. |
| Excessive vibration | Muffler bolts, handle bolts, crankshaft | Tighten all bolts to spec; inspect crankshaft bearings. |
| Oil not flowing to bar | Oil pump, oil line, tank vent | Check oil pump function; replace oil line if cracked; clean tank vent. |
| Fuel leak | Fuel line, tank gasket, carburetor | Replace cracked fuel line; replace tank gasket; check carburetor fittings. |
Service: Contact authorized Stihl servicing dealer. For dealer locator: www.stihlusa.com or 1-800-467-8445.