Husqvarna 340 Chainsaw Parts Manual

The Husqvarna 340 Chainsaw is a professional-grade chainsaw designed for demanding forestry and arborist work. This parts manual provides detailed diagrams, part numbers, and ordering information for the complete assembly, including the engine, cutting equipment, fuel system, ignition, and safety components. Below are key sections for identification, engine parts, cutting attachment, fuel system, ignition system, and maintenance.

Model Identification & Specifications

Identify your Husqvarna 340 using the serial number plate located on the rear of the crankcase. Key specifications for parts ordering.

Feature	Description
Engine Displacement	40.9 cc (2.5 cu. in.)
Power Output	2.2 kW (3.0 hp)
Fuel Tank Volume	0.47 L (0.12 US gal)
Oil Tank Volume	0.26 L (0.07 US gal)
Recommended Bar Length	13" to 18" (33 cm to 45 cm)
Chain Pitch	3/8" or .325"
Weight (Powerhead)	4.9 kg (10.8 lbs)
Ignition System	Electronic, SEM
Carburetor	Walbro HDA
Spark Plug	Champion RCJ7Y or equivalent

Engine Assembly Parts

Complete breakdown of the crankcase, crankshaft, bearings, seals, and associated hardware.

1. Crankcase (Halfs): Part # 501 87 41-01 (Left), 501 87 42-01 (Right). Includes all threaded inserts and mounting points.
2. Crankshaft: Part # 501 83 60-01. Includes main bearings (6202 C3) and oil seals.
3. Connecting Rod: Part # 501 59 43-01. Includes needle bearing and wrist pin.
4. Engine Mounting Hardware: Anti-vibration springs, bolts, and washers kit.

WARNING! Engine disassembly requires special tools and expertise. Incorrect assembly can cause catastrophic failure.

Cylinder & Piston Group

Detailed parts list for the cylinder, piston, rings, and gaskets.

1. Cylinder: Part # 503 87 47-01. Includes decompression valve port and transfer ports.
2. Piston: Part # 501 83 61-01. 40mm diameter with two ring grooves.
3. Piston Rings: Part # 501 59 45-01 (Set of 2).
4. Wrist Pin & Clips: Part # 501 59 44-01 (Pin), 501 20 33-01 (Circlips).
5. Cylinder Gasket: Part # 503 21 46-01.

CAUTION! Always replace the cylinder base gasket. Measure piston clearance during reassembly.

Fuel System & Tank

• Fuel Tank: Part # 501 87 43-01. Includes integrated fuel line fittings and vent.
• Carburetor (Walbro HDA): Part # 545 04 40-01. Kit includes diaphragm, gaskets, and inlet needle.
• Fuel Filter: Part # 501 83 65-01. In-tank type.
• Fuel Lines: Part # 501 20 35-01 (Supply), 501 20 36-01 (Return).
• Impulse Line: Part # 501 20 37-01. Connects crankcase to carburetor.
• Air Filter: Part # 503 87 48-01. Dual-stage foam element.
• Throttle Linkage: Kit includes throttle rod, spring, and lock plate.

Ignition System & Starter

Parts for the flywheel, ignition coil, spark plug, and recoil starter assembly.

Ignition Module (SEM): Part # 544 11 46-01. Includes stop switch wire.

Flywheel: Part # 501 83 62-01. Includes fan blades and keyway.

Starter Assembly: Part # 501 87 44-01. Complete recoil housing, pulley, spring, and rope.

Spark Plug Boot: Part # 501 20 38-01.

Stop Switch: Part # 501 20 39-01. Black/yellow wire assembly.

Cutting Attachment & Bar

Guide bar mounting, tensioning system, and bar nose parts.

1. Turn off chainsaw and ensure the chain brake is disengaged before parts replacement.
2. Remove bar nuts and side cover to access bar mount and tensioner.
3. Select correct bar length and gauge for your model (e.g., 15" .058 gauge).

Guide Bar (15", .058 gauge): Part # 501 83 66-01.

Bar Mounting Kit: Includes side cover, nuts, washers, and tensioner screw.

Tip: Regularly inspect the bar rail for wear and the sprocket nose for free rotation.

Chain & Sprocket

Drive sprocket, rim, and chain specifications. Supports .325" pitch, .058 gauge, 72 drive link chain.

1. Drive Sprocket (Rim Type): Part # 501 83 67-01 for .325" pitch.
2. Sprocket Rim: Part # 501 20 40-01. Replace when worn.
3. Chain (15", 72DL): Part # 501 83 68-01. Husqvarna H30 chain.
4. Chain Sharpening: Use 7/32" round file for cutters, flat file for depth gauges.
5. Sprocket Replacement: Remove clutch drum to access sprocket rim.

WARNING! Always match chain pitch and gauge to the bar and sprocket. A mismatched chain is dangerous.

Clutch & Drive

Centrifugal clutch assembly, drum, and drive components.

Clutch Assembly: Part # 501 87 45-01. Includes shoes, springs, and hub.

Clutch Drum: Part # 501 83 69-01.

Clutch Bearing: Part # 501 20 41-01.

Drive Shaft Seal: Part # 501 20 42-01.

Handle & Safety Features

Front and rear handle assemblies, anti-vibration system, chain brake, and throttle lock.

Front Handle: Part # 501 87 46-01. Includes throttle trigger and wiring harness.

Rear Handle: Part # 501 87 47-01. With fuel tank interface.

Chain Brake Band/Handle: Part # 501 83 70-01 (Band), 501 87 48-01 (Handle assembly).

Throttle Lockout: Part # 501 20 43-01.

CAUTION! Never operate a chainsaw with a damaged or malfunctioning chain brake or throttle lock.

Maintenance & Torque Specifications

Critical torque values for safe and proper assembly.

Component	Torque (Nm)	Torque (ft-lbs)
Cylinder Base Nuts	10-12	7.5-9
Spark Plug	25-30	18-22
Clutch	35-40	26-30
Flywheel Nut	40-45	30-33
Bar Mounting Nuts	8-10	6-7.5
Handle Mounting Bolts	9-11	6.5-8

Reset: After major service, reset the carburetor to factory settings (H: 1, L: 1, T: 1).

Parts Ordering & Exploded Views

Symptom / Need	Reference Diagram	Ordering Information
Engine won't start	Fuel System (Fig. 5), Ignition (Fig. 6)	Use part numbers listed. Contact dealer with serial number.
Loss of power	Cylinder/Piston (Fig. 4), Exhaust	Inspect piston/cylinder; order gasket set.
Chain won't stay tight	Cutting Attachment (Fig. 7)	Check bar mount wear, tensioner screw.
Oil leakage	Crankcase (Fig. 3), Oil Pump	Replace crankcase seals or oil line.
Vibration excessive	Handle & AV Mounts (Fig. 10)	Replace anti-vibration springs and buffers.

Service & Parts: Always use genuine Husqvarna parts. For diagrams and orders, visit www.husqvarna.com or contact your local authorized service dealer.