Stihl MS170 Chainsaw Parts Manual

The Stihl MS170 is a lightweight, easy-to-use chainsaw designed for occasional users and homeowners. This manual provides detailed parts identification, diagrams, and ordering information for maintenance and repair. Below are key sections covering safety, parts diagrams, specifications, maintenance, and troubleshooting.

1. Parts Overview 2. Engine Assembly Parts 3. Cutting Attachment Parts 4. Specifications 5. Maintenance Parts 6. Fuel & Lubrication System 7. Ignition System 9. Care & Storage 10. Regulatory Information 11. Troubleshooting

Parts Overview

Key components: Engine assembly, Cutting attachment (guide bar & chain), Fuel system, Ignition system, Starter assembly, Anti-vibration system.

Component Group	Description
Engine Assembly	Cylinder, piston, crankshaft, carburetor
Cutting Attachment	Guide bar, saw chain, sprocket, chain tensioner
Fuel System	Fuel tank, fuel filter, fuel lines, carburetor
Ignition System	Spark plug, ignition module, stop switch
Starter Assembly	Starter handle, rope, pulley, spring
Anti-Vibration System	Springs and buffers reducing operator fatigue
Air Filter System	Air filter cover, filter element, pre-cleaner
Chain Brake/Hand Guard	Safety mechanism to stop chain rotation
Muffler	Exhaust system with spark arrestor screen
Control Components	Throttle trigger, throttle lockout, choke lever

Engine Assembly Parts

Cylinder, piston, crankshaft, connecting rod, bearings, seals, and gaskets.

Cylinder: Part # 1128 020 1205 - Includes cylinder fins and exhaust port.
Piston: Part # 1128 030 2001 - With piston rings and wrist pin.
Crankshaft: Part # 1128 040 1801 - Main shaft with integrated crank webs.
Carburetor: Part # 1128 120 0600 - Zama C1Q-S267 or equivalent.
Bearings & Seals: Main bearings (6202 C3) and crankshaft seals.

WARNING! Engine disassembly requires special tools and expertise. Incorrect assembly can cause engine failure or injury.

Cutting Attachment Parts

Guide bar, saw chain, drive sprocket, chain tensioner, and bar nuts.

Guide Bar: Stihl Rollomatic E 14" (Part # 3003 000 3914) or 16" (3003 000 3915).
Saw Chain: Stihl Picco Micro 3 (PM3) chain, ¼" pitch, .043" gauge. Part # 63PM3-xx (xx = number of drive links).
Drive Sprocket: Spur sprocket, Part # 1128 642 2001.
Chain Tensioner: Part # 1128 640 3400 - Includes adjusting screw and pin.
Bar Nuts: M8 flange nuts, Part # 1128 647 3400.

CAUTION! Always use matched Stihl bar and chain combinations. Incorrect chain pitch or gauge can cause kickback or chain derailment.

Specifications

Engine Displacement: 30.1 cc (1.84 cu. in.)
Power Output: 1.5 kW (2.0 bhp)
Fuel Tank Volume: 0.25 L (8.5 fl. oz.)
Oil Tank Volume: 0.145 L (4.9 fl. oz.)
Guide Bar Lengths: 14" or 16" (35 cm or 40 cm)
Chain Pitch: ¼" (6.35 mm)
Chain Gauge: .043" (1.1 mm)
Weight (powerhead only): 3.9 kg (8.6 lbs)
Ignition System: Electronic, capacitor discharge (CDI)
Spark Plug: Bosch WSR 6F or equivalent, electrode gap 0.5 mm (0.020")

Maintenance Parts

Common replacement parts for routine maintenance.

Air Filter: Part # 1128 120 1601 - Foam filter element. Fuel Filter: Part # 0000 350 3502 - In-tank filter. Spark Plug: Bosch WSR 6F (Part # 0000 400 1305). Muffler Spark Arrestor Screen: Part # 0000 350 0930. Anti-Vibration Buffers: Set of 4, Part # 1128 790 1000. Starter Rope: Part # 0000 350 3200 - 3.5 mm diameter, 110 cm length.

Fuel & Lubrication System

Fuel tank, lines, filter, carburetor, oil pump, and oil lines.

Fuel Tank: Part # 1128 350 0601 - Polyethylene tank with integrated cap.
Fuel Lines: Supply and return lines, Part # 1128 358 0600 (kit).
Oil Pump: Manual plunger-type pump, Part # 1128 647 0600.
Oil Lines: From tank to pump and pump to bar pad, Part # 1128 647 0700.
Carburetor Repair Kit: Diaphragms, gaskets, needle valve, Part # 1128 007 1060.

Tip: Use only fresh, clean, unleaded gasoline (min. 89 octane) mixed with a high-quality 2-stroke engine oil at a 50:1 ratio (Stihl HP Ultra recommended).

Ignition System

Spark plug, ignition module, wiring, and stop switch.

Ignition Module (CDI): Part # 1128 400 1401 - Controls spark timing.
Spark Plug Boot: Part # 0000 350 0940 - Insulated high-tension lead connector.
Stop Switch: Part # 1128 962 1000 - Grounds ignition to stop engine.
Wiring Harness: Part # 1128 962 1200 - Connects switch to module.

WARNING! Disconnect the spark plug boot before performing any maintenance to prevent accidental starting.

Care & Storage

Clean saw after each use. For long-term storage, empty fuel tank and run carburetor dry. Store in a dry, cool place.

CAUTION! Never store the chainsaw with fuel in the tank for more than 30 days. Old fuel can damage the carburetor and fuel lines.

Regulatory Information

This chainsaw meets applicable ANSI/OPEI standards. It is equipped with a chain brake, low-kickback chain, and other safety features. The muffler contains a USDA-approved spark arrestor. Stihl is a registered trademark of Andreas Stihl AG & Co. KG. For genuine Stihl parts and service, contact an authorized Stihl dealer.

Troubleshooting

Symptom	Possible Cause	Corrective Action
Engine won't start	No spark, old fuel, clogged filter	Check spark plug; use fresh fuel mix; clean/replace air & fuel filters.
Engine runs poorly/dies	Clogged carburetor, improper adjustment	Clean carburetor; adjust idle and high-speed screws per manual.
Chain doesn't turn	Clutch worn, sprocket damaged, chain brake engaged	Check clutch shoes and springs; replace sprocket; disengage chain brake.
Chain doesn't oil	Oil tank empty, lines clogged, pump faulty	Fill oil tank; clean oil passages and bar groove; check oil pump function.
Excessive vibration	Worn anti-vibration buffers, loose components	Replace anti-vibration buffers; tighten all screws and nuts.

Service: For repairs beyond basic maintenance, take your Stihl MS170 to an authorized Stihl servicing dealer. Use only genuine Stihl parts.