Husqvarna 445 Chainsaw Manual

The Husqvarna 445 is a professional-grade chainsaw designed for demanding forestry and tree care work. It features a powerful X-Torq engine for reduced emissions and fuel consumption, an inertia-activated chain brake for enhanced safety, LowVib anti-vibration system, Smart Start for easy starting, and an ergonomic design for comfortable operation. Below are key sections for safety, features, assembly, operation, maintenance, and troubleshooting.

Features at a Glance

Key components: X-Torq engine, inertia-activated chain brake, LowVib system, Smart Start, combined choke/stop control, side-mounted chain tensioner, and ergonomic front and rear handles.

Safety Information

Read and understand all instructions before use. Always wear appropriate Personal Protective Equipment (PPE).

1. PPE Required: Safety helmet, hearing protection, eye protection (visor or goggles), protective gloves, chainsaw protective trousers, and safety boots.
2. Work Area Safety: Ensure a clear work area. Keep bystanders at a safe distance.
3. Kickback Awareness: Understand kickback causes and how to avoid them. Always hold saw firmly with both hands.
4. Fuel Safety: Refuel in a well-ventilated area with the engine stopped. Use fuel/oil mix as specified.

WARNING! Failure to follow safety instructions can result in serious injury or death. The chain brake is a safety device; ensure it is functioning correctly before each use.

Assembly & Preparation

Unpack and inspect contents. Assemble guide bar and chain.

1. Attach the guide bar: Place bar onto bar studs, ensuring the chain adjuster pin fits into the hole in the bar.
2. Fit the chain: Place chain over sprocket and onto guide bar, ensuring cutting teeth face forward on top of bar.
3. Tighten bar nuts: Hand-tighten nuts, then use tool to secure. Do not overtighten.
4. Adjust chain tension: Use side-mounted tensioner to achieve correct tension (chain should snap back when pulled from guide bar).
5. Fill fluids: Add recommended 2-stroke fuel/oil mix to fuel tank and chain oil to the oil tank.

CAUTION! Always wear protective gloves when handling the chain. Ensure chain is correctly installed to prevent derailment.

Specifications

• Engine Displacement: 45.7 cc
• Power Output: 2.4 kW (3.2 hp)
• Fuel Tank Volume: 0.5 liters
• Oil Tank Volume: 0.26 liters
• Recommended Bar Lengths: 13" to 18" (33 cm to 45 cm)
• Chain Pitch: 3/8" or .325" (depending on configuration)
• Weight (excluding cutting equipment): 4.9 kg
• Sound Pressure Level: 106 dB(A)
• Vibration Level (front/rear handle): 3.5/2.5 m/s²
• Emissions Compliance: EPA Phase II, EU Stage II

Controls and Components

Front Handle: Contains throttle trigger, throttle trigger lockout, and hand guard/chain brake lever. Rear Handle: Contains start/stop switch. Main Body: Housing for engine, fuel, and oil tanks.

Key Controls: Start/Stop Switch (I=On, O=Off), Choke Control (for cold starts), Throttle Trigger, Throttle Trigger Lockout (must be depressed to engage throttle), Chain Brake Lever (manual engagement), Inertia-Activated Chain Brake, Primer Bulb (on some models), Decompression Valve (eases starting).

Maintenance Points: Air Filter Cover, Spark Plug, Chain Tensioner, Chain Sprocket, Muffler.

Starting & Stopping

Cold Start:

1. Place saw on firm, flat ground. Engage chain brake.
2. Press decompression valve (if equipped).
3. Set choke control to full choke position.
4. Press primer bulb 4-6 times until fuel is visible (if equipped).
5. Pull starter handle until engine fires (approx. 2-5 pulls).
6. Move choke control to half-throttle position.
7. Pull starter handle again to start engine.
8. Allow to idle briefly, then disengage chain brake.

Warm Start: Follow steps but start from half-throttle position (no choke).

Stopping: Release throttle, allow engine to idle, move start/stop switch to "O" (Off) position.

Tip: Always engage the chain brake when starting or carrying the saw over short distances.

Operation & Cutting Techniques

Always use correct stance and grip. Keep saw at full throttle during cut.

1. Felling (Cutting Down a Tree): Plan escape path. Make notch cut (1/3 of tree diameter), then make felling cut from opposite side. Use felling wedge if necessary.
2. Limbing (Removing Branches): Work from base of tree to top. Let saw weight do the work; avoid forcing bar.
3. Bucking (Cutting Logs): Support log properly. Cut from top side, avoiding contact with ground to prevent chain dulling.
4. Kickback Prevention: Do not cut with tip/nose of guide bar. Be aware of wood tension and binding.

WARNING! Never operate chainsaw above shoulder height or with one hand. Be extremely cautious of kickback.

Maintenance Schedule

CAUTION! Always disconnect spark plug wire before performing maintenance. Use only genuine Husqvarna parts.

Chain Sharpening & Tensioning

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

1. Sharpening: Use correct round file size for chain pitch. File each cutter at recommended angle (typically 30°). Maintain equal length on all cutters. File depth gauges (rakers) with a flat file and gauge.
2. Tensioning: Chain should be snug against guide bar but pull freely by hand. Loosen bar nuts. Turn tensioning screw clockwise to tighten. Retighten bar nuts. Check tension when chain is cold and again after a short run (re-tension if necessary).

Tip: A loose chain can derail; an overtightened chain can damage the bar, sprocket, and engine.

Storage

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

1. Empty fuel tank and run engine until it stops to clear carburetor.
2. Remove chain, clean it, and store in oil.
3. Clean entire saw, especially cooling fins and air filter area.
4. Store in a dry, cool place, protected from dust and moisture.

CAUTION! Never store saw with fuel in the tank for extended periods. Old fuel can cause starting problems and damage the engine.

Troubleshooting

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

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