Stihl 012 AV Repair Manual

The Stihl 012 AV is a lightweight, professional-grade chainsaw featuring anti-vibration (AV) technology, electronic ignition, automatic oiling, and a reliable two-stroke engine. This repair manual provides comprehensive guidance for maintenance, troubleshooting, and repair procedures to ensure optimal performance and safety. Below are key sections covering safety, specifications, disassembly, engine repair, fuel system, ignition system, chain and bar maintenance, and troubleshooting.

1. Safety Precautions 2. Specifications & Technical Data 3. Tools Required 4. Disassembly & Assembly 5. Engine Repair 6. Fuel System 7. Ignition System 8. Chain & Bar Maintenance 9. Anti-Vibration System 10. Troubleshooting Guide 11. Parts Diagram & List

Safety Precautions

Always prioritize safety when performing repairs. Wear protective gear and work in a well-ventilated area.

Precaution	Description
Disconnect spark plug	Prevent accidental starting during repair
Use proper tools	Ensure correct torque and avoid damage
Handle fuel safely	Drain fuel tank before disassembly; avoid sparks
Chain safety	Wear cut-resistant gloves; ensure chain brake is engaged
Clean work area	Prevent contamination of engine components

Specifications & Technical Data

Engine Type: Single-cylinder, two-stroke, air-cooled.
Displacement: 31.8 cc.
Power Output: 1.5 kW (2.0 hp).
Fuel/Oil Mix: 50:1 (Stihl HP Ultra or equivalent).
Bar Length Options: 12" to 16".
Chain Pitch: 3/8" PMM.
Ignition: Electronic, non-adjustable.
Weight: 4.2 kg (9.3 lbs) without bar and chain.
Anti-Vibration: Spring-damper system.

Tools Required

Standard and specialty tools needed for repair.

Torx screwdrivers (T10, T15, T25).
Spark plug wrench (13/16").
Compression tester.
Carburetor adjustment tool.
Piston stop tool.
Clutch removal tool (Stihl 1122 893 4500).
Torque wrench (3-15 Nm range).

WARNING! Use genuine Stihl tools or equivalents to avoid damage.

Disassembly & Assembly

Step-by-step guide to dismantling and reassembling the saw.

Remove top cover: Unscrew two Torx screws.
Remove starter assembly: Detach spring and pulley.
Remove clutch and sprocket: Use clutch tool to loosen left-hand thread.
Separate engine from housing: Remove anti-vibration bolts.
Access cylinder and piston: Remove muffler and cylinder bolts.

Tip: Take photos during disassembly to aid reassembly.

Engine Repair

Procedures for piston, cylinder, crankshaft, and bearings.

Component	Inspection	Repair
Piston & Rings	Check for scoring, wear	Replace if compression below 110 psi
Cylinder	Inspect for scratches, plating damage	Hone lightly or replace
Crankshaft	Check runout (max 0.05 mm)	Replace if bent or worn
Bearings	Test for smooth rotation, no play	Press in new bearings
Seals	Inspect for leaks	Replace during reassembly

Fuel System

Carburetor adjustment, fuel line, and filter replacement.

Drain fuel tank completely.
Remove carburetor cover and air filter.
Adjust idle (L), high-speed (H), and idle speed screws.
Replace fuel filter and lines if cracked or brittle.
Test for leaks after reassembly.

Default Settings: L: 1 turn out, H: 1 turn out (fine-tune for performance).

Ignition System

Testing and replacing ignition coil, spark plug, and wiring.

Spark Plug: NGK BPMR7A, gap 0.5 mm.
Ignition Coil Test: Resistance primary 0.5-2 Ω, secondary 8-15 kΩ.
Stop Switch: Ensure continuity when off, open when on.
Flywheel: Check key for shearing; torque nut to 25 Nm.

CAUTION! Never crank engine with spark plug disconnected and grounded to cylinder.

Chain & Bar Maintenance

Sharpening, tensioning, and replacing chain and guide bar.

Sharpening: Use round file (4.0 mm) at 30° angle.
Tensioning: Loosen bar nuts, adjust tensioning screw.
Bar maintenance: Clean groove, flip regularly for even wear.
Sprocket: Replace if worn (teeth hook-shaped).

WARNING! Always wear gloves when handling chain.

Anti-Vibration System

Inspection and replacement of AV springs and dampers.

Locate four AV mounts connecting engine to housing. Check for cracked or sagging springs. Replace in pairs to maintain balance. Torque mounting bolts to 12 Nm.

Troubleshooting Guide

Symptom	Possible Cause	Corrective Action
Engine won't start	No spark, fuel issue, compression	Check spark plug, fuel filter, compression test
Engine runs poorly	Clogged carburetor, air leak	Clean carburetor, pressure test crankcase
Excessive vibration	Worn AV mounts, unbalanced parts	Replace AV springs, check clutch balance
Chain won't turn	Clutch worn, sprocket damaged	Inspect clutch shoes and drum, replace sprocket
Oil not pumping	Clogged oil passages, pump failure	Clean oil ports, replace oil pump

Parts Diagram & List

Key replacement parts with Stihl part numbers.

Cylinder: 1122 020 1201
Piston Kit: 1122 030 2001
Carburetor: 1122 120 0601
Ignition Coil: 1122 400 1301
Clutch Assembly: 1122 160 2001
AV Spring Set: 1122 790 4700

Ordering: Contact authorized Stihl dealer or visit www.stihlusa.com.