Husqvarna 440 Repair Manual

The Husqvarna 440 is a professional-grade chainsaw designed for demanding forestry and arborist work. This repair manual provides comprehensive instructions for maintenance, troubleshooting, and repair of the Husqvarna 440 chainsaw, covering the engine, fuel system, ignition, chain brake, cutting equipment, and electrical system. Below are key sections for safety, specifications, maintenance procedures, troubleshooting, and parts information.

Features at a Glance

Key components: X-Torq engine for reduced emissions, Air Injection air cleaning system, LowVib anti-vibration, combined choke/stop control, inertia activated chain brake, side-mounted chain tensioner.

Feature	Description
Engine Type	2-stroke, single cylinder, X-Torq
Displacement	40.9 cc (2.5 cu.in.)
Power Output	2.4 kW (3.2 hp)
Fuel Tank Volume	0.47 L (0.10 UK gal)
Oil Tank Volume	0.26 L (0.06 UK gal)
Recommended Bar Length	13" to 18" (33 cm to 45 cm)
Chain Pitch	3/8" or .325"
Weight (excl. cutting equipment)	4.9 kg (10.8 lbs)
Ignition System	Electronic, SEM
Vibration Dampening	LowVib system

Safety Precautions

Always wear appropriate Personal Protective Equipment (PPE) including helmet, eye protection, hearing protection, gloves, and chainsaw protective pants/boots.

1. Work Area Safety: Keep bystanders and animals at a safe distance. Ensure secure footing.
2. Before Starting: Check chain tension, sharpness, and lubrication. Ensure all guards are in place.
3. During Operation: Hold saw firmly with both hands. Do not operate above shoulder height.
4. Maintenance Safety: Disconnect spark plug wire before performing any maintenance. Use only Husqvarna approved parts.

WARNING! A chainsaw is a dangerous tool. Failure to follow safety instructions can result in serious injury or death.

Technical Specifications

• Engine Model: Husqvarna 440.
• Cylinder Bore: 40 mm (1.57 in).
• Piston Stroke: 32.6 mm (1.28 in).
• Maximum Power Speed: 9000 rpm.
• Idle Speed: 2700 rpm.
• Spark Plug: Champion RCJ7Y or equivalent, gap 0.5 mm (0.020").
• Fuel Mixture: 50:1 (2% oil) using high-quality 2-stroke oil for air-cooled engines.
• Carburetor: Zama C1Q-S199 or equivalent.
• Chain Oil: Use environmentally adapted chain oil with good adhesion characteristics.
• Sound Pressure Level: 106 dB(A).
• Sound Power Level: 119 dB(A).

Maintenance Schedule

Daily or before each use: Check chain tension, sharpness, and lubrication. Check all nuts and bolts for tightness. Clean air filter. Check for fuel/oil leaks.

Weekly (or every 10 operating hours): Clean cooling fins on cylinder and cylinder cover. Clean spark plug. Check spark arrestor screen in muffler (if equipped).

Monthly (or every 20 operating hours): Clean fuel filter. Check carburetor adjustment. Check starter mechanism. Check vibration dampeners.

Annually (or every 100 operating hours): Replace fuel filter. Clean carburetor diaphragm and check gaskets. Check clutch drum and sprocket for wear. Check all cables and connections.

Engine Repair

Cylinder and Piston: Inspect for scoring. Replace if deep scratches are present. Check piston rings for free movement and wear.

1. Remove muffler, cylinder cover, and spark plug.
2. Remove cylinder bolts and lift off cylinder.
3. Inspect piston and cylinder. Clean carbon deposits.
4. Reassemble with new gaskets. Torque cylinder bolts to 10 Nm (7.4 ft.lb).

Crankshaft and Bearings: Check for play and smooth rotation. Replace bearings if rough or noisy.

CAUTION! Use a torque wrench for all critical fasteners. Do not overtighten.

Fuel System

Components: Fuel tank, cap, filter, fuel line, carburetor.

1. Fuel Filter: Replace annually. Remove through filler neck with a wire hook.
2. Fuel Line: Check for cracks or brittleness. Replace if damaged.
3. Carburetor Adjustment: Factory pre-set. Only adjust if necessary using H (High) and L (Low) screws. Initial settings: L=1 turn open, H=1 turn open from lightly seated.
4. Carburetor Diaphragm: Remove carburetor cover and inspect diaphragm for stiffness or tears.

Tip: Always use clean, fresh fuel mixture. Stale fuel is a common cause of starting and running problems.

Ignition System

Components: Flywheel, ignition module (coil), spark plug, stop switch, wiring.

1. Spark Test: Remove spark plug, reconnect wire, hold plug base against cylinder head. Pull starter rope - look for strong blue spark.
2. No Spark: Check spark plug first. Then check wire connection to coil. Check stop switch circuit for continuity (should be open when switch is off/run).
3. Air Gap: Adjust gap between ignition module legs and flywheel magnets to 0.3 mm (0.012") using a feeler gauge.
4. Flywheel Key: Check for sheared key if timing is incorrect.

WARNING! High voltage present. Do not touch spark plug wire while pulling starter.

Chain Brake & Clutch

Chain Brake: Inertia activated. Test functionality regularly by rotating front hand guard forward towards bar.

Clutch: Centrifugal type. Inspect clutch shoes for wear and springs for fatigue.

1. Remove clutch cover, bar, and chain.
2. Hold piston with stopper tool, loosen clutch nut (left-hand thread).
3. Remove clutch drum, clutch assembly, and needle bearing.
4. Replace worn parts. Reassemble in reverse order. Torque clutch nut to 45 Nm (33 ft.lb).

CAUTION! Always engage chain brake before working on cutting equipment.

Cutting Equipment

Guide Bar: Inspect for straightness, rail wear, and sprocket nose condition. Clean bar groove and oil holes.

Chain: Sharpen regularly with correct file size. Maintain correct depth gauge setting. Replace when stretched beyond adjuster capacity or teeth are severely worn.

Sprocket: Check drive sprocket (in clutch drum) for wear. Replace if teeth are hooked or worn thin.

Chain Tensioning: Loosen bar nuts, adjust with side-mounted screw, tighten bar nuts while lifting bar tip. Check tension when cold.

Electrical System

Stop Switch: Test continuity. Should be closed (0 ohms) in STOP position, open in RUN position.

Wiring Harness: Inspect for chafing, especially where it passes through chassis.

Starter Motor: Not applicable - uses recoil starter. Check recoil spring and pawls for wear.

Lighting (if equipped): Check bulb and connections.

Troubleshooting

Symptom	Possible Cause	Corrective Action
Engine will not start	No spark, stale fuel, flooded	Check spark, use fresh fuel, wait and try with choke off.
Engine starts but dies	Clogged fuel filter, dirty air filter, carb adjustment	Replace fuel filter, clean air filter, adjust L screw.
Lacks power at high speed	Clogged spark arrestor, dirty air filter, H adjustment	Clean spark arrestor screen, clean air filter, adjust H screw.
Chain does not stop when brake engaged	Worn brake band, dirty mechanism	Replace brake band, clean and lubricate pivot points.
Excessive vibration	Loose components, worn dampeners, unbalanced chain	Tighten all fasteners, replace dampeners, sharpen chain evenly.
Chain throws oil but does not lubricate bar	Clogged oil holes, worn oil pump	Clean bar oil holes, check and replace oil pump if faulty.

Reset: For electronic ignition module, disconnect spark plug wire for 1 minute to reset any fault codes (if applicable).

Service: For genuine Husqvarna parts and technical support, contact your local authorized Husqvarna dealer or visit www.husqvarna.com.