Stihl 015 Service Manual

The Stihl 015 is a lightweight, professional-grade chainsaw designed for demanding cutting tasks. This manual provides comprehensive service, maintenance, and repair information for technicians and qualified users. It covers safety procedures, technical specifications, engine systems, fuel system, ignition system, cutting equipment, troubleshooting, and assembly/disassembly instructions. Always follow safety guidelines and use genuine Stihl parts for optimal performance and safety.

Safety Information

Working on chainsaws involves significant risks. Always prioritize personal safety and the safety of others.

Hazard	Precaution
Fuel & Fire	Work in well-ventilated area; no smoking or open flames.
Sharp Components	Wear cut-resistant gloves when handling chain, guide bar, or sprocket.
Hot Surfaces	Allow engine and muffler to cool completely before servicing.
Springs & Tension	Use proper tools; be aware of stored energy in recoil starter and AV springs.
Battery Disconnect	Disconnect spark plug wire before any service to prevent accidental starting.

WARNING! Failure to follow safety instructions can result in serious injury or death. Service should be performed by qualified personnel.

Technical Specifications

• Model: Stihl 015
• Engine Type: Single-cylinder, two-stroke, air-cooled
• Displacement: 31.8 cc (1.94 cu. in.)
• Power Output: 1.6 kW (2.1 hp)
• Fuel/Oil Mix: 50:1 (Stihl HP Ultra or equivalent ISO-L-EGD)
• Ignition System: Electronic, flywheel magneto
• Carburetor: Tillotson or Zama diaphragm type
• Starter: Rewind starter with rope
• Guide Bar Lengths: 12" to 16" (30 cm to 40 cm)
• Chain Pitch: 3/8" PM or .325"
• Weight (powerhead): Approx. 4.2 kg (9.3 lbs)

Engine Overview

The engine is the core of the chainsaw. Key components include cylinder, piston, crankshaft, connecting rod, and crankcase.

1. Cylinder & Piston: Inspect for scoring, carbon buildup, and ring wear. Measure piston clearance.
2. Crankshaft & Bearings: Check for play, runout, and bearing smoothness.
3. Crankcase Seals: Critical for maintaining engine vacuum/pressure. Replace if leaking.
4. Muffler: Remove and clean spark arrestor screen regularly.
5. Cooling System: Ensure cylinder fins and fan housing are clean for proper airflow.

CAUTION! Use a torque wrench for all critical fasteners (cylinder, crankcase) to specified values.

Fuel System Service

Includes fuel tank, filter, lines, and carburetor.

1. Drain old fuel from tank.
2. Replace in-tank fuel filter. Inspect fuel lines for cracks, stiffness, or leaks.
3. Clean carburetor exterior before removal. Disassemble on a clean surface.
4. Check diaphragm, gaskets, metering lever height, and inlet needle valve.
5. Clean all jets and passages with compressed air (do not use wire).
6. Reassemble with new diaphragm/gasket kit if worn.

Tip: Always pressure and vacuum test the carburetor after service.

Ignition System Service

Components: Flywheel, ignition module (coil), spark plug, stop switch, and wiring.

Testing:

1. Spark Plug: Check gap (0.020" / 0.5mm). Replace if fouled or electrode worn.
2. Ignition Module: Check air gap between coil legs and flywheel (0.2-0.4 mm). Test primary/secondary resistance with multimeter per specifications.
3. Flywheel: Inspect for cracks, damaged keyway, or magnets losing strength.
4. Wiring: Inspect for chafing, breaks, and secure connections, especially at stop switch.

WARNING! A weak spark is a common cause of hard starting. Ensure all grounds are clean and tight.

Cutting Equipment

Guide bar, chain, drive sprocket, and clutch assembly.

1. Guide Bar: Inspect for straightness, rail wear, and groove cleanliness. Dress rails and clean oil holes.
2. Chain: Sharpen regularly with correct file size. Check for damaged, stretched, or binding links.
3. Drive Sprocket: Replace if worn (spur or rim type). A worn sprocket accelerates chain wear.
4. Clutch: Inspect shoes for wear and springs for integrity. Clean drum interior.
5. Chain Brake: Test function. Inspect band, mechanism, and handle for proper operation.

CAUTION! Always wear gloves. A sharp, properly tensioned chain is safer and more efficient.

Carburetor Adjustment

Factory settings are a starting point. Final adjustment must be made with a warmed-up engine and a tachometer.

Screw	Function	Initial Setting (turns out)
L (Low Speed)	Idle and low-speed mixture	1 turn
H (High Speed)	High-speed/WOT mixture	1 turn
LA or I (Idle Speed)	Engine idle RPM	1 turn

1. Start with factory settings. Warm up engine for 5 minutes.
2. Adjust L screw for fastest, smoothest idle. Then set idle speed with LA screw to ~2800 RPM (no chain movement).
3. Adjust H screw for maximum RPM (do not exceed max RPM spec ~13,500). Then richen slightly (1/8 turn) for engine safety.
4. Re-check idle and acceleration. Chain must not move at idle.

WARNING! An overly lean H setting will cause engine seizure. Always final-tune under load if possible.

Disassembly & Assembly

General sequence for major service.

1. Remove cutting attachment (bar, chain, clutch cover).
2. Remove top cover, air filter, and carburetor.
3. Remove starter assembly, muffler, and ignition coil.
4. Separate crankcase halves (requires special tool to press crankshaft from bearing).
5. Remove piston pin circlips, then pin, piston, and connecting rod.
6. Inspect all parts. Replace seals, bearings, and gaskets during reassembly.
7. Assemble in reverse order. Use sealant on crankcase mating surfaces as specified. Torque fasteners to specification.

Tip: Take photos during disassembly and organize parts systematically.

Troubleshooting Guide

Symptom	Possible Cause	Corrective Action
Engine won't start	No spark, flooded, fuel issue	Check spark, plug condition. Dry plug, choke off, pull with throttle open. Check fuel delivery.
Engine starts then dies	Fuel filter clogged, tank vent blocked, carb issues	Replace fuel filter. Check tank vent. Service carburetor.
Lacks power/overheats	Clogged muffler, air filter, lean carb setting, compression low	Clean muffler screen & air filter. Check H screw setting. Perform compression test.
Chain oil not flowing	Oil hole clogged, pump defective, line disconnected	Clean bar oil hole and tank filter. Inspect oil pump drive and lines.
Excessive vibration	Unbalanced flywheel, loose components, AV mounts bad	Check flywheel key. Tighten all fasteners. Inspect anti-vibration mounts.

Maintenance Schedule

• Before Each Use: Check chain tension, sharpness, and lubrication. Inspect for loose fasteners.
• Daily (or every 10 hrs): Clean air filter. Check fuel filter. Clean cooling fins and guide bar groove.
• Weekly (or every 50 hrs): Clean spark arrestor screen. Inspect spark plug. Check clutch drum and sprocket.
• Monthly (or every 100 hrs): Service carburetor (diaphragm kit). Check fuel lines. Inspect crankcase seals.
• Annually (or every 500 hrs): Decarbon cylinder head. Check piston/cylinder condition. Replace clutch springs if worn.

Parts List & Diagrams

Refer to official Stihl 015 IPL (Illustrated Parts List) for exact part numbers, quantities, and assembly views. Key assembly groups include:

1. Crankcase Group (including bearings and seals)
2. Cylinder & Piston Group
3. Carburetor & Fuel System Group
4. Ignition & Starter Group
5. Clutch & Sprocket Group
6. AV Handle & Covers Group
7. Cutting Attachment Group (Bar, Chain, Sprocket)

Note: Always use genuine Stihl replacement parts to ensure compatibility, performance, and safety.

Ordering & Support: Contact an authorized Stihl dealer or visit www.stihlusa.com for parts and technical support.