Husqvarna 240 Chainsaw Service Manual

The Husqvarna 240 is a lightweight, professional-grade chainsaw designed for demanding users. This service manual provides detailed instructions for maintenance, troubleshooting, and repair of the chainsaw's engine, cutting equipment, and safety systems. Below are key sections covering safety, specifications, maintenance procedures, troubleshooting, and parts information.

1. Safety Information 2. Specifications 3. Maintenance Schedule 4. Engine Service 5. Fuel System 6. Ignition System 7. Cutting Equipment 8. Troubleshooting 9. Parts Diagrams 10. Warranty & Support

Safety Information

Always prioritize safety when operating or servicing the Husqvarna 240 chainsaw. Wear appropriate personal protective equipment (PPE).

Safety Symbol	Meaning
⚠️ WARNING	Risk of personal injury. Follow instructions carefully.
🔥 FIRE HAZARD	Risk of fire. Keep away from flammable materials.
⚡ ELECTRICAL	Risk of electric shock. Disconnect spark plug before service.
🔧 SERVICE	Service required. Refer to authorized dealer if unsure.

WARNING! Always stop the engine and disconnect the spark plug before performing any maintenance or repair.

Specifications

Engine Type: 2-stroke, single cylinder.
Displacement: 40.9 cc.
Power Output: 2.0 kW (2.7 hp).
Fuel Tank Capacity: 0.33 liters.
Oil Tank Capacity: 0.25 liters.
Bar Length Options: 13", 15", 16".
Chain Pitch: 3/8" Low Profile.
Weight (excl. cutting equipment): 4.4 kg.
Ignition System: Electronic, air gap 0.3 mm.

Maintenance Schedule

Regular maintenance ensures optimal performance and longevity.

Daily: Check chain tension, sharpness, and lubrication. Clean air filter.
Weekly: Inspect spark plug, fuel filter, and bar/chain wear.
Monthly: Clean cooling fins, check carburetor adjustments, inspect anti-vibration mounts.
Annually: Replace fuel lines, inspect clutch and sprocket, decarbonize exhaust port.

CAUTION! Use only genuine Husqvarna replacement parts and recommended lubricants.

Engine Service

Procedures for cylinder, piston, and crankshaft service.

Cylinder Removal: Remove muffler, cylinder cover, and cylinder bolts. Lift cylinder carefully.
Piston Inspection: Check for scoring, ring wear, and pin bearing play.
Crankshaft Seals: Inspect for leaks. Replace if damaged to prevent air leaks.
Reassembly: Use new gaskets. Torque cylinder bolts to 10 Nm in crisscross pattern.

Tip: Mark all parts during disassembly for correct reassembly.

Fuel System

Carburetor adjustment and fuel line replacement.

Carburetor Adjustment: Factory settings: L=1 turn out, H=1 turn out. Fine-tune for optimal idle and acceleration.
Fuel Filter: Replace if clogged. Use Husqvarna part # 501 87 94-01.
Fuel Lines: Inspect for cracks. Replace every 2 years or if hardened.
Fuel Mix: Use 50:1 mix of unleaded gasoline (min 90 octane) and Husqvarna 2-stroke oil.

WARNING! Never run the engine without proper fuel/oil mixture to avoid engine seizure.

Ignition System

Spark plug, ignition coil, and stop switch testing.

Component	Specification	Test Procedure
Spark Plug	NGK BPMR7A, gap 0.5 mm	Check for fouling, cracks, correct gap.
Ignition Coil	Air gap 0.3 mm	Measure resistance: primary 0.2-0.3 Ω, secondary 4-6 kΩ.
Stop Switch	Normally closed	Continuity test: should show 0 Ω when pressed.

Cutting Equipment

Chain, bar, and sprocket maintenance.

Chain Sharpening: Use 4.0 mm round file. Maintain 30° top plate angle, 10° side plate angle.
Bar Maintenance: Clean bar groove, flip bar regularly for even wear.
Sprocket Inspection: Replace if teeth are hooked or worn. Use matching pitch sprocket.
Chain Tension: Adjust so chain snaps back when pulled from bar. Tighten bar nuts to 9-10 Nm.

CAUTION! Always wear cut-resistant gloves when handling the chain.

Troubleshooting

Symptom	Possible Cause	Corrective Action
Engine won't start	No spark, flooded, fuel issue	Check spark plug, dry cylinder, clean carburetor.
Engine runs poorly	Clogged filter, incorrect mix	Clean air/fuel filter, adjust carburetor, use proper fuel mix.
Chain doesn't turn	Clutch worn, sprocket damaged	Inspect clutch springs and drum, replace sprocket.
Excessive vibration	Loose parts, AV mounts worn	Tighten all bolts, replace anti-vibration mounts.
Overheating	Dirty cooling fins, lean mix	Clean fins, check carburetor H setting, use correct mix.

Parts Diagrams

Refer to official Husqvarna parts catalog for exploded views and part numbers. Key assemblies:

Cylinder & Piston Assembly (Part # 537 25 40-02)
Carburetor Kit (Part # 545 00 42-01)
Clutch Assembly (Part # 537 23 31-02)
Chain Brake Handle (Part # 537 27 32-01)
Ignition Module (Part # 537 23 33-01)

Note: Always use genuine Husqvarna parts for warranty compliance and safety.

Warranty & Support

Husqvarna 240 comes with a 2-year commercial warranty when serviced by authorized dealers. Warranty covers defects in materials and workmanship.

Support Contacts:

Customer Service: 1-800-487-5962
Technical Support: 1-800-448-7543
Website: www.husqvarna.com/us
Find a Dealer: Use dealer locator on website