Stihl 034 AV Parts Manual

The Stihl 034 AV is a professional-grade chainsaw known for its durability and performance. This parts manual provides detailed diagrams, part numbers, and ordering information for the complete assembly and maintenance of the Stihl 034 AV chainsaw. Below are key sections covering identification, engine components, fuel system, ignition system, cutting equipment, and ordering procedures.

1. Identification & Specifications 2. Engine Assembly & Crankcase 3. Cylinder & Piston Group 4. Fuel System & Carburetor 5. Ignition System & Electronics 6. AV Anti-Vibration System 7. Clutch, Sprocket & Chain Brake 8. Cutting Attachment & Bar/Chain 9. Starter Assembly & Rewind 10. Covers & External Parts 11. Parts Ordering & Exploded Views

Identification & Specifications

Key identification: Model 034 AV, Serial Number location on crankcase. Engine type: Single cylinder, two-stroke, air-cooled.

Specification	Description
Displacement	61.5 cc (3.75 cu. in.)
Power Output	3.6 kW (4.9 HP)
Fuel Tank Capacity	0.55 L (18.6 fl. oz.)
Oil Tank Capacity	0.26 L (8.8 fl. oz.)
Weight (powerhead)	6.2 kg (13.7 lbs) without cutting attachment
Ignition System	Electronic, breakerless
Carburetor	Stihl Zama or equivalent diaphragm type
Recommended Bar Length	40 cm (16") to 50 cm (20")
Chain Pitch	3/8" or .325"
Spark Plug	Bosch WSR6F or equivalent

Engine Assembly & Crankcase

Major components: Crankcase halves, crankshaft, bearings, seals, and mounting hardware.

Crankcase Halves: Right and left halves, includes part numbers for complete assemblies and individual halves.
Crankshaft Assembly: Includes crankshaft, connecting rod, big end bearing, and crank pins.
Main Bearings: Ball bearings for crankshaft support.
Crankcase Seals: Oil seals for crankshaft ends to prevent air leaks.
Mounting Screws & Dowels: Hardware for assembling crankcase halves.

WARNING! Crankcase assembly requires precise alignment and proper torque specifications. Use factory service tools.

Cylinder & Piston Group

Components for combustion chamber: Cylinder, piston, rings, wrist pin, and circlips.

Cylinder: Includes part number for complete cylinder with decompression valve port.
Piston: Aluminum piston with two ring grooves.
Piston Rings: Two compression rings.
Wrist Pin: Connects piston to connecting rod.
Circlips: Retain wrist pin in piston.
Gaskets & Base Gasket: For cylinder-to-crankcase seal.

CAUTION! Always replace circlips during reassembly. Ensure ring end gaps are properly spaced.

Fuel System & Carburetor

Fuel Tank: Includes tank, cap, and fuel line fittings.
Carburetor Assembly: Stihl Zama or Walbro model with part number.
Carburetor Repair Kit: Includes diaphragms, gaskets, needle valve, and filter.
Fuel Lines: Supply and return lines with clamps.
Fuel Filter: In-tank filter element.
Impulse Line: Connects crankcase to carburetor pump diaphragm.
Choke/Throttle Linkage: Rods and springs for control lever operation.

Ignition System & Electronics

Components for spark generation and stopping: Ignition module, spark plug, wire, stop switch, and wiring harness.

Ignition Module (Coil): Mounts on fan housing, includes air gap specification. Spark Plug Boot: Insulated boot and wire. Stop Switch: Grounding switch for engine shutdown. Wiring Harness: Connects stop switch to ignition module. Flywheel: Includes magnets for ignition timing and fan blades for cooling.

AV Anti-Vibration System

Springs and dampeners to reduce operator fatigue.

Front AV Buffer: Rubber dampeners between engine and front handle.
Rear AV Buffer: Springs or rubber elements between engine and rear handle/tank.
AV Mounting Bolts & Sleeves: Hardware for securing the system.

Tip: Inspect AV buffers regularly for cracks or deterioration. Replace in sets.

Clutch, Sprocket & Chain Brake

Components for drive and safety: Centrifugal clutch, drum, sprocket, and chain brake band.

Clutch Assembly: Includes shoes, springs, and drum.
Clutch Drum & Bearing: Drum that holds rim sprocket or spur sprocket.
Sprocket: Rim sprocket (part number varies by pitch) or fixed spur sprocket.
Chain Brake Band: Steel band for stopping the chain.
Chain Brake Handle & Mechanism: Lever, springs, and linkage to engage brake.
Clutch Cover: Outer cover with part number and chain catcher.

WARNING! Always disengage chain brake before starting. Replace worn sprockets to prevent chain damage.

Cutting Attachment & Bar/Chain

Guide bar, saw chain, tensioning system, and oil pump.

Guide Bar: Stihl Rollomatic E or ES series, various lengths. Saw Chain: Part numbers for 3/8" or .325" pitch, .063" gauge. Bar Mounting Hardware: Nuts, studs, and washers. Chain Tensioner: Screw, pin, and adjuster. Chain Sprocket Nose: Tip sprocket or solid nose. Oil Pump: Manual or automatic (depending on variant), includes drive gear and lines. Oil Output Adjustment Screw: For controlling oil flow to bar.

Starter Assembly & Rewind

Components for manual starting: Starter housing, pulley, spring, rope, and handle.

Starter Housing: Plastic housing with part number.
Rewind Spring: Clock spring for rope retraction.
Starter Pulley & Pawls: Pulley with engagement pawls for crankshaft dog.
Starter Rope: Braided nylon rope with specified length.
Starter Handle: Plastic grip with knot hole.
Rope Guide & Grommet: For smooth rope travel.

CAUTION! Use caution when handling rewind spring under tension. Wear safety gloves.

Covers & External Parts

External casings, handles, and controls.

Top Cover/Cylinder Cover: Includes muffler cover and air filter cover. Air Filter Cover: With latch and snorkel. Air Filter: Foam or felt element. Muffler: Spark-arresting muffler with gasket and heat shield. Front Handle: Wrap-around handle with part number. Rear Handle/Tank Assembly: Combined fuel tank and rear handle. Throttle Trigger & Lockout: Interlock safety lever and throttle cable. Master Control Lever: Combined choke/throttle lock/stop control.

Parts Ordering & Exploded Views

Component Group	Diagram Ref. Number	Ordering Notes
Crankcase Group	Fig. 1	Order crankcase halves as matched set if replaced.
Cylinder Group	Fig. 2	Specify decompression valve (if equipped) when ordering cylinder.
Fuel System	Fig. 3	Carburetor kit includes all necessary gaskets and diaphragms.
Ignition System	Fig. 4	Provide serial number for correct ignition module version.
Clutch & Brake	Fig. 5	Specify rim sprocket pitch (.325" or 3/8") when ordering.
Starter	Fig. 6	Starter rope sold by length; specify exact cm/inches.
AV System	Fig. 7	Replace all AV buffers simultaneously for balanced damping.
Cutting Attachment	Fig. 8	Specify bar length, pitch, and gauge for chain and bar.

How to Order: Use the official Stihl part number from this manual. Contact an authorized Stihl dealer with the model (034 AV) and serial number.

Service & Support: For technical assistance or to locate a dealer, visit www.stihl.com or contact Stihl Incorporated.