CS-520 Chainsaw Manual

The CS-520 Chainsaw is a professional-grade 52cc gasoline-powered chainsaw designed for heavy-duty cutting tasks. Features include a 20-inch guide bar, automatic oiling system, anti-vibration handles, 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, automatic chain oiler, anti-vibration system, chain brake, decompression valve, side-access chain tensioner.

Feature	Description
Engine	52cc 2-stroke gasoline engine
Guide Bar	20-inch professional grade
Chain Oil	Automatic oiling system with manual override
Anti-Vibration	Rubber-mounted handles for reduced fatigue
Safety Features	Chain brake, throttle lockout, right-hand guard
Starting System	Decompression valve for easy starting
Weight	12.8 lbs (without bar and chain)
Fuel Capacity	20.3 fl oz (600 ml)
Oil Capacity	10.1 fl oz (300 ml)
Spark Plug	NGK BPMR7A gap 0.020 inch

Safety Instructions

Read all instructions before operation. Wear proper safety gear.

1. Always wear: Safety glasses, hearing protection, gloves, chainsaw chaps, steel-toe boots.
2. Clear work area of obstacles and bystanders.
3. Check chain tension and sharpness before each use.
4. Never operate above shoulder height or on a ladder.
5. Use proper cutting techniques: avoid kickback zone.

WARNING! Chainsaw can cause serious injury or death. Always follow safety procedures. Keep hands away from moving chain.

Assembly & Setup

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

1. Attach guide bar: Loosen bar nuts, position bar, align chain, tighten nuts.
2. Adjust chain tension: Chain should snap back when pulled from bar.
3. Fill fuel: Use 50:1 gasoline/oil mixture (89 octane minimum).
4. Fill chain oil: Use SAE 30 or equivalent bar and chain oil.
5. Prime carburetor: Press primer bulb 5-7 times until fuel visible.

CAUTION! Fuel is flammable. Fill outdoors away from ignition sources.

Specifications

• Engine Displacement: 52cc
• Power Output: 3.2 HP
• Guide Bar Length: 20 inches
• Chain Pitch: 3/8 inch
• Chain Gauge: 0.050 inch
• Fuel Capacity: 20.3 fl oz (600 ml)
• Oil Capacity: 10.1 fl oz (300 ml)
• Weight: 12.8 lbs (without bar and chain)
• 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 Functions

Main controls: Throttle trigger, throttle lockout, choke control, stop switch, chain brake, decompression valve.

Right Side: Throttle trigger, throttle lockout, chain brake lever. Left Side: Choke control, decompression valve, stop switch. Rear: Fuel cap, oil cap, primer bulb.

Chain brake: Manual activation via front hand guard; automatic activation via inertia. Decompression valve: Reduces compression for easier starting. Chain tensioner: Side-mounted dial for quick adjustments.

Operating Instructions

Starting procedure: Place on flat surface, engage chain brake, set controls.

1. Cold start: Set choke to FULL, decompression valve IN, pull starter rope 3-5 times.
2. Warm start: Choke to OFF, decompression valve OUT, pull starter rope.
3. Cutting techniques: Use lower part of bar for cutting; avoid tip to prevent kickback.
4. Felling trees: Plan escape path, make notch cut, then felling cut.
5. Limbing: Work from trunk outward, support log properly.

Tip: Let engine warm up 30 seconds before cutting. Keep chain sharp for best performance.

Maintenance & Care

Daily maintenance ensures optimal performance and safety.

1. Clean air filter: Remove, wash in soapy water, dry completely.
2. Check spark plug: Clean electrode, adjust gap to 0.020 inch.
3. Clean cooling fins: Remove debris from cylinder fins.
4. Inspect chain: Check for damaged or missing cutters.
5. Clean guide bar: Remove bar, clean groove, rotate weekly.
6. Check chain brake: Test function before each use.

WARNING! Always disconnect spark plug before maintenance. Allow engine to cool completely.

Chain Sharpening

Sharp chain cuts efficiently and safely. Sharpen when sawdust becomes fine.

1. Secure bar: Use vise to hold bar steady.
2. File size: Use 5/32 inch round file for 3/8 pitch chain.
3. Filing angle: Maintain 30-degree angle on cutters.
4. File depth gauges: Use flat file to maintain 0.025 inch below cutter.
5. Equal strokes: Apply equal pressure on all cutters.

CAUTION! Wear gloves when handling chain. File in one direction only.

Storage Guidelines

Proper storage prevents fuel system damage and corrosion.

1. Drain fuel: Run engine until carburetor is empty.
2. Remove chain: Clean and soak in oil, store separately.
3. Clean saw: Remove all sawdust and debris.
4. Lubricate: Spray metal parts with corrosion inhibitor.
5. Store: In dry place, covered, away from children.

Tip: For long-term storage, add fuel stabilizer to fresh fuel, run 2 minutes before draining.

Warranty Information

2-year limited warranty for residential use, 90 days for commercial use. Warranty covers defects in materials and workmanship. Not covered: Normal wear, misuse, improper maintenance, unauthorized repairs. For warranty claims, contact authorized service center with proof of purchase. For support, visit www.cs-chainsaws.com or contact 1-800-555-CHAINS.

Troubleshooting

Symptom	Possible Cause	Corrective Action
Engine won't start	Fuel, spark, compression	Check fuel mixture, spark plug, decompression valve.
Engine runs poorly	Air filter, carburetor	Clean air filter; adjust carburetor screws.
Chain won't turn	Brake engaged, clutch	Disengage chain brake; check clutch springs.
Chain throws oil	Oil system	Check oil pump, oil line, oil tank vent.
Excessive vibration	Balance, mounting	Check anti-vibration mounts; ensure bar nuts tight.
Chain dulls quickly	Cutting material	Avoid dirt, sand; sharpen properly; check depth gauges.

Service Intervals: Every 50 hours: Clean carburetor, check fuel filter. Every 100 hours: Replace spark plug, check piston rings.

Service Centers: 1-800-555-CHAINS; www.cs-chainsaws.com