Husqvarna 40 Chainsaw Manual

The Husqvarna 40 is a lightweight, professional-grade chainsaw designed for demanding cutting tasks. It features a high-performance engine, low vibration system, efficient air filtration, and easy-start technology. Below are key sections for safety, features, assembly, operation, maintenance, and troubleshooting.

1. Features at a Glance 2. Assembly & Preparation 3. First-Time Operation 4. Specifications 5. Controls and Settings 6. Chain & Bar Maintenance 7. Cutting Techniques 8. Safety Features 10. Care & Cleaning 11. Regulatory Information 12. Troubleshooting

Features at a Glance

Key components: Engine, Guide Bar, Saw Chain, Chain Brake, Throttle Trigger, Stop Switch, Front Hand Guard, Fuel Tank, Oil Tank.

Feature	Description
Engine Type	2-stroke, air-cooled gasoline engine
Displacement	40.9 cc
Power Output	2.0 kW (2.7 hp)
Fuel Tank Volume	0.47 L
Oil Tank Volume	0.26 L
Guide Bar Length	13" to 16" (33 cm to 40 cm)
Chain Pitch	3/8" Low Profile
Weight (excl. cutting equipment)	4.4 kg
Sound Pressure Level	106 dB(A)
Vibration Level (front/rear handle)	3.5/4.0 m/s²

Assembly & Preparation

Unpack and inspect all parts. Assemble on a clean, stable surface.

Attach Guide Bar and Chain: Place bar on mounting studs, fit chain around bar sprocket and drive sprocket, adjust tension.
Fill Fuel Tank: Use fresh gasoline mixed with 2-stroke oil (50:1 ratio).
Fill Chain Oil Tank: Use recommended bar and chain oil.
Check Chain Brake: Ensure front hand guard moves freely and activates brake.

WARNING! Always wear protective equipment: helmet, gloves, eye protection, hearing protection, and chainsaw chaps.

First-Time Operation

Perform pre-start checks before first use.

Check Chain Tension: Chain should be snug against bar but pull freely.
Prime Engine: Press primer bulb 5-6 times until fuel is visible.
Set Choke: Move to COLD START position.
Start Engine: Place on ground, hold rear handle with right foot, pull starter cord briskly.
Warm Up: Allow engine to run at idle for 30 seconds before cutting.

CAUTION! Never start the chainsaw in a closed area. Ensure clear escape path.

Specifications

Engine: 40.9 cc 2-stroke.
Power: 2.0 kW (2.7 hp).
Fuel/Oil Mix: 50:1 (High-quality 2-stroke oil).
Bar Length Options: 13", 15", 16".
Chain Type: 3/8" Low Profile, .050" gauge.
Ignition System: Electronic, capacitor discharge.
Carburetor: Walbro diaphragm type.
Starter: Recoil starter with decompression valve.
Safety Features: Chain brake, inertia-activated, throttle lockout, right hand guard.

Controls and Settings

Main Controls: Throttle Trigger, Throttle Lockout, Stop Switch, Choke Control, Primer Bulb, Chain Brake Lever.

Adjustments: Chain Tension (side knob), Idle Speed (screw near carburetor), High/Low Speed Jets (carburetor adjustment screws).

Operation: Pull throttle lockout back to release throttle trigger. Press stop switch to stop engine. Activate chain brake by pushing front hand guard forward.

Chain & Bar Maintenance

Regular maintenance ensures optimal performance and safety.

Sharpening Chain: Use round file (4.0 mm) at 30° angle. File all cutters to equal length.
Checking Depth Gauges: Use depth gauge tool to maintain correct height (0.025").
Cleaning Bar: Remove bar, clean groove and oil holes. Rotate bar regularly for even wear.
Lubrication: Ensure automatic oiler is working; adjust flow if necessary.

Tip: Always disconnect spark plug wire before performing maintenance.

Cutting Techniques

Proper technique reduces fatigue and risk of kickback.

Felling: Plan escape path. Make notch cut (1/3 diameter), then felling cut leaving hinge.
Limbing: Stand on opposite side of log. Cut from top down, using bar as a lever.
Bucking: Support log properly. Use undercut for tension wood, top cut for compression.
Kickback Prevention: Keep nose of bar away from objects. Maintain firm grip, high RPM.

WARNING! Never cut above shoulder height. Be aware of kickback zone (upper quadrant of bar tip).

Safety Features

Chain Brake: Stops chain within milliseconds if activated manually or by inertia. Throttle Lockout: Prevents accidental throttle engagement. Right Hand Guard: Protects hand from broken chain. Decompression Valve: Reduces pulling force when starting.

Care & Cleaning

After each use: Clean air filter, check spark arrestor screen, wipe exterior, inspect for damage.

CAUTION! Allow engine to cool before cleaning. Use compressed air for cooling fins and air filter.

Regulatory Information

EPA & CARB Certified: Meets emission standards for handheld engines. EU Noise Directive: Complies with outdoor noise emission limits. For support, visit www.husqvarna.com or contact authorized service dealer. Always use genuine Husqvarna parts.

Troubleshooting

Symptom	Possible Cause	Corrective Action
Engine won't start	No spark, fuel issue, flooded	Check spark plug, fresh fuel mix, set choke to off, pull with throttle open.
Engine runs poorly	Dirty air filter, clogged fuel filter	Clean/replace air filter, replace fuel filter.
Chain doesn't oil	Empty oil tank, clogged oil holes	Fill oil tank, clean bar oil holes, check oil pump.
Chain comes off bar	Loose chain, worn bar, damaged drive links	Tighten chain, inspect/replace bar, check chain for damage.
Excessive vibration	Loose parts, unbalanced chain	Tighten all bolts/nuts, sharpen chain evenly.

Service Intervals: Air filter: Every 10 hours. Spark plug: Every 50 hours. Fuel filter: Every 100 hours.

Service: Contact authorized Husqvarna dealer for major repairs.