520 Chainsaw Manual

The 520 Chainsaw is a professional-grade gasoline-powered chainsaw designed for heavy-duty cutting tasks. It features a 52cc 2-stroke engine, 20-inch guide bar, automatic chain oiler, anti-vibration system, chain brake, decompression valve, and easy-start technology. Below are key sections for safety, features, assembly, operation, maintenance, and troubleshooting.

Features at a Glance

Key components: 52cc 2-stroke engine, 20-inch guide bar, Chain brake, Automatic oiler, Anti-vibration system, Decompression valve.

Feature	Description
Engine displacement	52cc 2-stroke air-cooled engine
Guide bar length	20 inches (50cm)
Chain pitch	3/8 inch
Automatic chain oiler	Lubricates chain during operation
Chain brake	Stops chain immediately in kickback situations
Anti-vibration system	Reduces operator fatigue
Decompression valve	Easier starting
Fuel tank capacity	550ml
Oil tank capacity	260ml
Weight (without bar/chain)	5.2kg

Assembly & Preparation

Unpack and inspect all components. Assemble on clean, flat surface.

1. Attach guide bar: Remove side cover, align bar with tension pin, install chain with cutting teeth facing forward.
2. Adjust chain tension: Turn tension screw until chain snaps back when pulled from bar.
3. Install bar nuts: Tighten securely but do not overtighten.
4. Fill fuel tank: Use 50:1 gasoline/oil mixture (89 octane minimum).
5. Fill oil tank: Use high-quality bar and chain oil.

WARNING! Always wear protective gear: helmet, goggles, gloves, ear protection, chainsaw chaps, and steel-toed boots.

First-Time Operation

Complete assembly and safety checks before starting.

1. Check chain tension: Chain should move freely but not sag from bar.
2. Prime engine: Press primer bulb 5-6 times until fuel is visible.
3. Set choke: Move to FULL position for cold start.
4. Engage chain brake: Push forward until it clicks.
5. Pull starter cord: Firm, steady pulls until engine fires.
6. Disengage choke: Move to RUN position after engine starts.
7. Test chain brake: Release brake and ensure chain stops when engaged.

CAUTION! Never start chainsaw on ground - hold firmly with one foot on rear handle.

Specifications

• Engine Type: 2-stroke, single cylinder, air-cooled.
• Displacement: 52cc.
• Power Output: 3.2kW (4.3hp).
• Fuel: Gasoline with 2-stroke oil (50:1 ratio).
• Guide Bar: 20 inches standard.
• Chain Speed: 22 m/s at maximum RPM.
• Idle Speed: 2,800 RPM.
• Maximum RPM: 13,500.
• Sound Level: 105 dB(A) at operator's ear.
• Vibration Level: 4.2 m/s² front handle, 5.1 m/s² rear handle.

Controls and Settings

Main controls: Throttle trigger, Throttle lockout, Chain brake, Choke, Primer bulb, Decompression valve, Master control lever.

Operation: Press throttle lockout while squeezing throttle trigger. Chain brake engages automatically during kickback or manually by pushing forward. Choke has three positions: RUN, HALF, FULL. Decompression valve reduces compression for easier starting.

Adjustments: Chain tension via side tension screw. Carburetor adjustment screws (H - high speed, L - low speed, T - idle) - factory set, only adjust if necessary.

Fuel & Lubrication

Fuel mixture: 50:1 ratio (89 octane gasoline to 2-stroke oil). Bar oil: SAE 30 or special chain oil.

1. Mix fuel in separate container before filling tank.
2. Use fresh gasoline (less than 30 days old).
3. Fill oil tank with bar oil before each use.
4. Check oil flow: Run chainsaw over light surface - oil line should appear.

Tip: Never use automotive motor oil or recycled oil in chain oiler.

Cutting Techniques

Basic cutting positions and methods for safe operation.

1. Felling: Plan escape path, make notch cut, then back cut leaving hinge.
2. Limbing: Work from trunk outward, keep bar tip clear.
3. Bucking: Support log properly, cut from top, avoid pinching.
4. Pruning: Cut branches in sections from tip toward trunk.
5. Plunge cutting: Only for experienced users - use lower quadrant of bar tip.

WARNING! Beware of kickback - keep firm grip, never cut with bar tip, maintain sharp chain.

Safety Features

Chain brake: Stops chain within 0.15 seconds during kickback. Throttle lockout: Prevents accidental throttle engagement. Right-hand guard: Protects from broken chain. Anti-vibration: Reduces fatigue and improves control. Decompression valve: Easier starting with less pull force.

Maintenance & Cleaning

Daily maintenance: Clean air filter, check chain tension, sharpen chain, clean cooling fins, check bar for wear.

Weekly: Clean spark arrestor, check spark plug, clean fuel filter, inspect anti-vibration mounts.

CAUTION! Always disconnect spark plug wire before maintenance. Use only manufacturer-approved parts.

Regulatory Information

EPA Phase III compliant: Meets emission standards. CARB certified for California use. ANSI B175.1 safety standard compliance. EU noise directive 2000/14/EC. For support, visit www.chainsaw520.com or contact 1-800-555-CHAINS. Serial number located on engine housing.

Troubleshooting

Symptom	Possible Cause	Corrective Action
Engine won't start	Fuel, spark, compression	Check fuel mixture, spark plug, compression, carburetor settings.
Engine runs poorly	Air filter, fuel filter	Clean/replace air filter, check fuel filter, adjust carburetor.
Chain doesn't oil	Oil tank, oiler hole	Check oil level, clean oiler hole, check oil pump.
Chain comes off bar	Tension, bar wear	Adjust tension properly, check bar for wear, replace if grooved.
Excessive vibration	Mounts, balance	Check anti-vibration mounts, ensure chain is sharp and balanced.
Overheating	Air flow, fuel mix	Clean cooling fins, check fuel mixture, adjust carburetor.

Reset: Return carburetor to factory settings if adjusted improperly.

Service: 1-800-555-CHAINS; www.chainsaw520.com