Husqvarna 445 Operators Manual

The Husqvarna 445 is a professional-grade gasoline chainsaw designed for demanding cutting tasks. It features a powerful X-Torq® engine for reduced emissions and fuel consumption, an inertia-activated chain brake (Quickstop®), LowVib® anti-vibration system, Air Injection™ air cleaning, combined choke/stop control, and an ergonomic design for superior handling. Below are key sections for safety, features, assembly, operation, maintenance, and troubleshooting.

Features at a Glance

Key components: X-Torq® engine, Quickstop® inertia chain brake, combined choke/stop control, side-mounted chain tensioner, Air Injection™, LowVib® handles, and a transparent fuel tank.

Safety Instructions

Read and understand all instructions before operation. Always wear appropriate PPE.

1. Personal Protective Equipment (PPE): Always wear chainsaw protective trousers, safety boots, gloves, eye protection (visor/goggles), and hearing protection.
2. Work Area Safety: Keep bystanders and animals at least 15 meters away. Ensure secure footing. Do not operate in poor weather or visibility.
3. Kickback Zone: Be aware of the upper quadrant of the guide bar tip. Never cut with this part of the bar.
4. Chain Brake: Check function before each use. The brake should engage manually and by inertia.
5. Fuel Safety: Refuel outdoors, with engine stopped and cool. Use clean, unleaded gasoline mixed with 2-stroke oil (50:1 ratio).

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

Assembly & Preparation

Unpack and inspect contents. Assemble the guide bar and chain.

1. Attach Guide Bar & Chain: Place the bar on the bar studs. Loop the chain around the bar, ensuring cutting teeth face forward on top. Fit the drive links into the bar groove. Adjust tension with side screw.
2. Fill Fuel & Oil: Fill the fuel tank with correct 50:1 fuel/oil mix. Fill the chain oil tank with special chainsaw bar and chain oil.
3. Check Chain Tension: A new chain stretches. Check and adjust tension frequently during first hours of use.
4. Perform Pre-Start Check: Ensure all nuts and bolts are tight. Check that the chain brake functions correctly.

CAUTION! Always wear protective gloves when handling the chain. The chain is extremely sharp.

Specifications

• Engine Displacement: 45.7 cm³ (2.8 cu. in.)
• Power Output: 2.4 kW (3.2 hp)
• Fuel/Oil Ratio: 50:1 (Unleaded gasoline to Husqvarna 2-stroke oil)
• Recommended Bar Lengths: 40 cm (16"), 45 cm (18")
• Chain Pitch/Gauge: .325" / 1.5 mm (0.058")
• Idling Speed: 2700 rpm
• Maximum Power Speed: 9000 rpm
• Sound Pressure Level: 106 dB(A)
• Vibration Levels (Front/Rear Handle): 3.5/4.5 m/s²
• Dry Weight (without bar & chain): 4.9 kg (10.8 lbs)

Controls and Components

Familiarize yourself with all controls before starting the engine.

Main Controls: - Throttle Trigger: Controls engine speed. Releases to idle. - Throttle Trigger Lockout: Must be depressed to press the throttle trigger. - Stop Switch: Moves between RUN and STOP positions. - Choke Control: Used for cold starting. - Combined Choke/Stop Control (Decompression Valve): Reduces cylinder pressure for easier starting. - Chain Brake Lever (Front Hand Guard): Engages the chain brake manually when pushed forward. - Master Control Lever: Combines choke, stop, and decompression functions. - Side-Mounted Chain Tensioner: For adjusting chain tension.

Maintenance Points: Air filter cover, Spark plug, Fuel filter, Chain oil pump adjustment screw.

Starting & Stopping the Saw

Cold Start:

1. Place saw on flat ground. Engage chain brake.
2. Press the fuel pump (primer) 5-6 times.
3. Set master control lever to choke position (full up).
4. Pull starter handle until engine fires (max 5 pulls).
5. Move master control lever to half-throttle position.
6. Pull starter handle again until engine starts.
7. Blip throttle to disengage fast idle. Release chain brake.

Warm Start: Set master control lever to half-throttle position and pull starter cord.

Stopping: Release throttle, allow engine to idle briefly, then move stop switch to STOP.

WARNING! Never drop-start the saw. Always engage the chain brake when starting.

Basic Cutting Techniques

Always use full throttle when cutting. Let the chain do the work.

1. Felling (Cutting Down a Tree): Plan escape path (45-degree angle behind tree). Make notch cut (1/3 of tree diameter). Make felling cut from opposite side, leaving hinge wood.
2. Limbing (Removing Branches): Stand on left side of trunk. Cut branches on opposite side of trunk first. Use the trunk as a barrier between you and the chain.
3. Bucking (Cutting Logs): Support log off ground. Cut from top down. For logs under tension, cut from the tension side first to avoid pinching.
4. Kickback Prevention: Maintain a firm grip. Do not cut with the tip. Use a sharp chain. Be aware of the saw's position.

CAUTION! Beware of pinch points. Never cut above shoulder height.

Maintenance Schedule

Chain Sharpening & Tensioning

A sharp, properly tensioned chain is essential for safety and performance.

1. Tensioning: Loosen bar nuts. Turn side tensioner screw clockwise until chain fits snugly against bar (can be pulled by hand). Tighten bar nuts. Re-check tension.
2. Sharpening: Use correct round file size (4.0 mm / 5/32"). File at 30-degree angle. File all cutters to equal length. File depth gauges with a flat file and gauge.
3. Lubrication: Ensure chain oil tank is filled. Check oil flow by running saw at idle over light-colored surface; a line of oil should appear.

Tip: Rotate the file consistently. Sharpen at first sign of dullness (sawdust instead of chips).

Storage

Prepare saw for storage if not used for more than 30 days.

1. Empty the fuel tank and run the engine until it stops to clear carburetor.
2. Remove, clean, and oil the chain. Store separately.
3. Clean the entire saw thoroughly.
4. Remove spark plug, add a teaspoon of engine oil into cylinder, pull starter cord slowly, reinstall plug.
5. Store in a dry, clean, and secure place, out of reach of children.

CAUTION! Never store a chainsaw with fuel in the tank for long periods. Fuel can degrade and damage engine components.

Troubleshooting

Service: For repairs beyond basic maintenance, contact an authorized Husqvarna service dealer.

Support: Husqvarna AB, SE-561 82 Huskvarna, Sweden. www.husqvarna.com