CS 305 Chainsaw Manual

The CS 305 is a professional-grade gasoline-powered chainsaw designed for demanding cutting tasks. It features a 50.2cc engine, 20-inch guide bar, automatic chain oiling, anti-vibration system, inertia-activated chain brake, easy-start system, and ergonomic handles. Below are key sections for safety, features, assembly, operation, maintenance, and troubleshooting.

Features at a Glance

Key components: 50.2cc 2-stroke engine, 20-inch guide bar, automatic oil pump, chain brake, decompression valve, anti-vibration system, translucent fuel tank.

Feature	Description
Engine displacement	50.2cc 2-stroke air-cooled engine
Guide bar length	20 inches (50cm) professional grade
Chain pitch	3/8 inch, 0.050 gauge
Automatic oiling	Adjustable chain lubrication system
Chain brake	Inertia-activated safety brake
Anti-vibration	Reduced vibration handles for comfort
Decompression valve	Easier starting with reduced compression
Fuel capacity	15.2 fl oz (450ml) translucent tank
Oil capacity	8.5 fl oz (250ml) chain oil tank
Weight (dry)	12.8 lbs (5.8kg) without fuel/oil

Safety Information

Always wear proper PPE: helmet with face shield, hearing protection, gloves, chainsaw chaps, and steel-toe boots.

1. Clear work area of obstacles and bystanders.
2. Check chain tension and sharpness before each use.
3. Never operate with damaged or missing safety devices.
4. Maintain secure footing and balance at all times.
5. Shut off engine when carrying or not in use.

WARNING! Chainsaw kickback can cause serious injury. Always hold saw firmly with both hands, maintain proper chain sharpness, and avoid contact with tip of guide bar.

Assembly & Preparation

Unpack and inspect all components. Assembly requires attaching guide bar and chain, filling fluids.

1. Attach guide bar: Loosen bar nuts, position bar on studs, align chain sprocket.
2. Install chain: Place chain over bar with cutting teeth facing forward, engage drive links.
3. Adjust chain tension: Tighten bar nuts finger-tight, adjust tension screw until chain snaps back when pulled from bar.
4. Final tighten: Secure bar nuts while holding bar tip up.
5. Fill fluids: Mix fuel 50:1 with 2-stroke oil, fill chain oil reservoir.

CAUTION! Use only recommended 2-stroke oil and fresh gasoline. Never use automotive oil or straight gasoline.

Specifications

• Engine: 50.2cc 2-stroke, air-cooled.
• Power Output: 3.2 HP at 9,500 RPM.
• Fuel/Oil Mix: 50:1 (2.6oz oil per gallon).
• Bar Length: 20 inches (50cm).
• Chain Speed: 65 ft/sec at max RPM.
• Sound Level: 105 dB(A) at operator's ear.
• Vibration Level: Front handle: 4.2 m/s², Rear handle: 5.1 m/s².
• Warranty: 2 years commercial, 5 years residential.

Controls and Components

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

Right Side: Throttle trigger with lockout, rear handle, stop switch. Left Side: Chain brake handle, front handle, choke lever, decompression valve. Top: Fuel cap, oil cap, air filter cover, spark plug.

Safety features: Chain brake (manual/inertia), throttle lockout, right-hand guard, chain catcher, muffler shield.

Starting & Stopping

Cold start procedure (follow exactly):

1. Place saw on clear, level ground.
2. Engage chain brake by pushing forward.
3. Set choke to full position.
4. Press decompression valve (if equipped).
5. Pull starter rope slowly until resistance felt, then pull briskly.
6. After engine fires, move choke to half position.
7. Pull starter again until engine runs.
8. Disengage chain brake before cutting.

Stopping: Release throttle, press stop switch. Emergency stop: Activate chain brake.

Operating Procedures

Basic cutting techniques for felling, limbing, and bucking.

1. Felling: Plan escape path, make notch cut 1/3 diameter, make felling cut 2 inches above notch.
2. Limbing: Work from trunk outward, support limb when possible.
3. Bucking: Support log off ground, cut from top down, avoid pinching chain.
4. Kickback prevention: Maintain firm grip, don't cut with bar tip, keep chain sharp.
5. Fueling: Stop engine, cool for 5 minutes, clean area around cap.

WARNING! Never operate above shoulder height or on ladder. Watch for tension in wood (compression/tension wood).

Maintenance Schedule

Daily: Check chain tension, sharpness, fluids. Clean air filter, check for loose fasteners.

Weekly: Clean cooling fins, check spark plug, clean guide bar groove.

Monthly: Clean fuel filter, check fuel lines, clean carburetor air passage.

Seasonally: Replace spark plug, clean muffler screen, check anti-vibration mounts.

Lubrication: Bar tip sprocket daily, clutch bearing monthly with high-temperature grease.

Chain Sharpening

Tools needed: Round file (5/32"), file guide, depth gauge tool.

1. Secure bar in vise.
2. Match file size to chain (5/32" for 3/8" pitch).
3. File at 30° angle, maintain consistent pressure.
4. File all cutters to same length.
5. Check depth gauges after every 3-4 sharpenings.
6. File depth gauges to 0.025" below cutter.

Tip: Sharpen when chain produces fine dust instead of chips. Rotate file to prevent flat spots.

Storage Guidelines

Long-term storage (over 30 days):

1. Drain fuel tank and run carburetor dry.
2. Remove chain, clean and soak in oil.
3. Clean entire saw, especially cooling fins.
4. Remove spark plug, add 1 tsp oil to cylinder, pull starter slowly to coat.
5. Store in dry place, cover to prevent dust.

CAUTION! Never store with fuel in tank. Fuel deteriorates and can damage carburetor.

Troubleshooting

Symptom	Possible Cause	Corrective Action
Engine won't start	No spark/flooded/old fuel	Check spark plug, use fresh fuel mix, don't flood.
Engine runs then dies	Clogged fuel filter/vent	Replace fuel filter, clean tank vent.
Poor cutting performance	Dull chain/wrong tension	Sharpen chain, adjust tension properly.
Chain won't turn	Brake engaged/clutch worn	Disengage brake, inspect clutch drum.
Excessive vibration	Loose parts/unbalanced chain	Tighten all fasteners, balance chain.
Chain throws oil	Over-oiling/incorrect oil	Adjust oiler, use proper chain oil.

Service: Authorized service centers only. For dealer locations: 1-800-555-CHAIN or www.cs305chainsaw.com