stihl 034 av service manual pdf

The STIHL 034 AV is a professional-grade gasoline-powered chainsaw featuring Anti-Vibration (AV) technology, a robust engine, and durable construction for demanding forestry and cutting applications. This service manual provides comprehensive technical information for maintenance, troubleshooting, and repair procedures. Below are key sections covering safety, specifications, maintenance schedules, engine service, fuel system, ignition system, cutting equipment, and troubleshooting guides.

1. Features at a Glance 2. Safety Information 3. Technical Specifications 4. Maintenance Schedule 5. Engine Service 6. Fuel System 7. Ignition System 8. Cutting Equipment 9. Anti-Vibration System 10. Troubleshooting 11. Parts List & Diagrams

Features at a Glance

Key components: Engine with electronic ignition, Anti-Vibration system, Decompression valve, Chain brake, Quick-stop inertia feature, Adjustable automatic oiler, and Side-access chain tensioner.

Feature	Description
Engine Displacement	Approx. 56.5 cc (3.45 cu. in.)
Power Output	High-performance engine for professional use
Anti-Vibration System (AV)	Reduces operator fatigue through dampened handles
Decompression Valve	Easier starting by reducing cylinder pressure
Chain Brake	Hand-activated safety feature to stop chain rotation
Automatic Oiler	Adjustable lubrication for guide bar and chain
Ignition System	Electronic, maintenance-free ignition module
Fuel Tank Capacity	Approx. 0.75 liters (25.4 fl. oz.)
Oil Tank Capacity	Approx. 0.32 liters (10.8 fl. oz.)
Recommended Bar Length	40 cm to 50 cm (16" to 20")

Safety Information

Always read and understand the operator's manual before use. Wear appropriate personal protective equipment (PPE).

Personal Protective Equipment: Wear safety glasses, hearing protection, gloves, chainsaw chaps/pants, and sturdy boots.
Pre-Operation Check: Inspect chainsaw for damage, ensure chain brake functions, check chain tension and sharpness.
Safe Operation: Maintain secure footing, keep bystanders away, be aware of kickback zone.
Fuel Safety: Use correct fuel/oil mix (50:1), refuel in well-ventilated area with engine off and cool.

WARNING! Improper use can cause serious injury or death. Never operate a damaged or malfunctioning chainsaw.

Technical Specifications

Model: STIHL 034 AV
Engine Type: Single-cylinder, two-stroke, air-cooled
Displacement: 56.5 cm³ (3.45 cu. in.)
Power Output: Approx. 3.3 kW (4.4 HP)
Idle Speed: 2,800 rpm
Maximum Power Speed: 12,500 rpm
Fuel/Oil Ratio: 50:1 (STIHL HP Ultra or equivalent)
Ignition: Electronic, air gap 0.3 mm (0.012 in.)
Spark Plug: Bosch WSR 6F or equivalent, gap 0.5 mm (0.020 in.)
Weight (powerhead): Approx. 6.2 kg (13.7 lbs)
Sound Pressure Level: Approx. 106 dB(A)
Vibration Level (front/rear handle): Complies with relevant standards due to AV system.

Maintenance Schedule

Access OSD via TV MENU or SETUP (DVD). Front Panel: POWER, OPEN/CLOSE, AUTO/DPMS, MUTE.

Daily/Before Use: Check chain tension and sharpness, inspect guide bar, check all fasteners, clean air filter, check fuel and oil levels.

Weekly/Every 10 Operating Hours: Clean spark arrestor screen (if equipped), inspect spark plug, clean cooling fins, check anti-vibration elements.

Monthly/Every 20 Operating Hours: Clean fuel filter, check carburetor adjustment, inspect clutch and sprocket, check chain brake function.

Annually/Every 100 Operating Hours: Replace fuel filter, replace spark plug, clean carburetor (if necessary), check cylinder compression.

Engine Service

Cylinder and Piston: Inspect for scoring, measure wear. Crankshaft and Bearings: Check for play and smooth rotation. Decompression Valve: Ensure it seals and operates correctly.

Remove engine covers and muffler for access.
Use a piston stop to hold crankshaft when removing clutch or flywheel.
Measure cylinder bore and piston diameter for wear limits.
Replace crankshaft seals during major overhauls.

Tip: Use STIHL special tools (e.g., piston stop, flywheel puller) for proper disassembly.

Fuel System

Includes fuel tank, filter, lines, and carburetor (likely Walbro or Zama).

Fuel Tank: Check for cracks, clean sediment.
Fuel Filter: Replace if clogged; located inside tank.
Fuel Lines: Inspect for cracks/hardening; replace if damaged.
Carburetor: Adjust idle (L), high speed (H), and idle speed screws. Clean jets and diaphragms if performance issues arise.
Fuel Cap: Ensure vent is clear.

WARNING! Use only clean, fresh fuel mix. Stale fuel can cause starting and running problems.

Ignition System

Electronic ignition module, spark plug, and stop switch.

Testing: Check for spark with plug grounded to cylinder. Resistance check of ignition coil primary/secondary windings. Ensure air gap between flywheel and ignition module is 0.3 mm (0.012 in.).

Cutting Equipment

Guide Bar: Inspect for wear, straightness, and groove condition. Chain: Sharpen regularly, check depth gauges. Sprocket: Inspect for wear (replace if worn). Chain Tensioner: Adjust via side-access knob.

CAUTION! Always use STIHL recommended bar and chain combinations. A worn sprocket will accelerate chain wear.

Anti-Vibration System

Consists of rubber dampeners mounted between the engine/powerhead and the front/rear handles.

Inspection: Check rubber elements for cracks, hardening, or separation. Replacement: Replace dampeners as a set if excessive vibration is felt.

Troubleshooting

Symptom	Possible Cause	Corrective Action
Engine will not start	No spark, flooded, fuel issue	Check spark, dry plug, ensure fresh fuel, check fuel lines/filter.
Engine starts but dies	Clogged fuel filter, carb adjustment	Replace fuel filter, adjust carburetor L and H screws.
Loss of power	Dirty air filter, clogged spark arrestor, compression loss	Clean/replace air filter, clean spark arrestor, check compression.
Excessive vibration	Worn AV dampeners, unbalanced cutting equipment	Inspect and replace AV elements, balance/rotate guide bar.
Chain does not oil	Clogged oil passages, faulty oiler pump	Clean oil ports, check oiler pump function and adjustment.
Chain brake does not engage	Contaminated band, weak spring	Clean brake band and mechanism, replace spring if necessary.

Reset: For electronic issues, disconnect spark plug wire and pull starter 5-10 times to clear flooded condition.

Service: For technical support and genuine parts, contact an authorized STIHL servicing dealer.

Parts List & Diagrams

Refer to the official STIHL 034 AV Parts Catalog for exploded views and part numbers. Common replacement parts include: Air filter, Spark plug (Bosch WSR 6F), Fuel filter, Carburetor repair kit, AV dampeners, Clutch drum/sprocket, Guide bar, and Saw chain.

Note: Always use genuine STIHL parts to ensure performance, safety, and warranty compliance.