Craftsman 20 Inch 50cc Chainsaw Manual

The Craftsman 20 Inch 50cc Chainsaw is a professional-grade gas-powered chainsaw featuring a 50cc 2-stroke engine, 20-inch Oregon bar and chain, automatic oiler, anti-vibration system, quick-stop chain brake, tool-less chain tensioning, and easy-pull starting. Designed for heavy-duty cutting, limbing, and felling of medium to large trees. Below are key sections for safety, features, assembly, operation, maintenance, and troubleshooting.

Features at a Glance

Key components: 50cc 2-stroke engine, 20-inch cutting bar, automatic chain oiler, anti-vibration handles, chain brake, primer bulb, choke control, and safety throttle lock.

Assembly & Setup

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

1. Attach the guide bar: Place bar onto mounting studs, align chain with sprocket, adjust tension.
2. Install chain: Ensure cutting teeth face forward on top of bar.
3. Fill oil tank: Use bar and chain oil (not motor oil).
4. Mix fuel: Use fresh unleaded gasoline (89 octane minimum) with 2-cycle oil at 50:1 ratio.
5. Check all fasteners: Ensure bar nuts, handles, and covers are secure.

WARNING! Always wear protective gloves during assembly. Ensure chain brake is engaged when not cutting.

Safety Instructions

Read all safety warnings before operation.

1. Personal Protective Equipment (PPE): Always wear safety glasses, hearing protection, gloves, steel-toe boots, and chainsaw chaps.
2. Clear work area: Remove tripping hazards; keep bystanders at least 30 feet away.
3. Check chain brake: Test before each use by pushing handle forward.
4. Proper stance: Stand with feet shoulder-width apart, firm grip on handles.
5. Kickback zone: Avoid contact with upper quadrant of guide bar tip.

DANGER! Never operate chainsaw above shoulder height or on a ladder. Do not cut with the tip of the bar.

Specifications

• Engine Displacement: 50cc (3.05 cu in)
• Power Output: 3.2 HP @ 9000 RPM
• Fuel Mix Ratio: 50:1 (unleaded gas to 2-cycle oil)
• Bar Length: 20 inches
• Chain Pitch: .325 inches
• Chain Gauge: .050 inches
• Drive Links: 72
• Idle Speed: 2800 RPM
• Max Engine Speed: 13,500 RPM
• Sound Power Level: 112 dB(A)
• Vibration Level: 4.2 m/s² (front handle), 6.5 m/s² (rear handle)

Controls and Components

Main controls located on top and rear handle.

Front Handle: Chain brake lever, throttle lockout, hand guard.

Rear Handle: Throttle trigger, choke lever, primer bulb, stop switch.

Right Side: Spark plug, muffler, decompression valve (if equipped).

Left Side: Fuel cap, oil cap, air filter cover.

Operation: Pull choke for cold start, press primer bulb 5-6 times, engage throttle lock, pull starter cord. Disengage choke once engine fires.

Fuel & Oil Mixing

Use fresh unleaded gasoline (89 octane or higher) and high-quality 2-cycle engine oil.

1. Mix in approved fuel container: Add gasoline first, then oil.
2. Ratio: 50:1 (2.6 oz oil per 1 gallon gas).
3. Shake container thoroughly before refueling.
4. Fill fuel tank to 80% capacity to allow for expansion.
5. Use bar and chain oil in separate oil tank (do not mix with fuel).

CAUTION! Never use automotive motor oil or old gasoline. Store fuel mix no longer than 30 days.

Starting & Operation

Starting procedure for cold and warm engine.

1. Place chainsaw on flat ground, clear of debris.
2. Engage chain brake by pushing handle forward.
3. Set stop switch to "ON" position.
4. Pull choke lever to full choke (cold start only).
5. Press primer bulb 5-6 times until fuel is visible.
6. Hold rear handle with right foot, pull starter cord briskly 2-3 times until engine pops.
7. Move choke to half position, pull starter until engine starts.
8. Allow 30-second warm-up at idle before disengaging chain brake.
9. Squeeze throttle trigger to begin cutting.

WARNING! Always start on ground, never drop-start. Keep both hands on handles during operation.

Maintenance Schedule

Note: Always disconnect spark plug wire before performing maintenance.

Chain Sharpening & Replacement

Sharp chain improves cutting efficiency and safety.

1. Secure bar: Use vise or clamp.
2. File size: Use 5/32" round file for .325 pitch chain.
3. Filing angle: Maintain 30° cutting angle.
4. File strokes: 2-3 strokes per tooth, equal pressure.
5. Depth gauges: Use depth gauge tool to maintain proper height.
6. Replacement: Replace chain when drive links are worn or teeth cannot be sharpened.

Tip: Rotate chain regularly to ensure even bar wear.

Storage

Proper storage prevents fuel system damage and corrosion.

1. Drain fuel tank or add fuel stabilizer.
2. Run engine until carburetor is dry.
3. Remove chain, clean and soak in oil.
4. Clean entire saw, especially cooling fins and air filter.
5. Store in dry, cool place away from ignition sources.
6. Cover to prevent dust accumulation.

CAUTION! Never store with fuel in tank for more than 30 days without stabilizer.

Troubleshooting

Service: For technical support, contact Craftsman at 1-888-331-4569 or visit www.craftsman.com.