Craftsman 20 50cc Chainsaw Manual

The Craftsman 20 50cc Chainsaw is a powerful, professional-grade chainsaw designed for demanding cutting tasks. Featuring a 50cc 2-stroke engine, 20-inch guide bar, automatic oiler, chain brake, anti-vibration system, and easy-start technology. Below are key sections for safety, features, assembly, operation, maintenance, and troubleshooting.

Features at a Glance

Key components: 50cc 2-stroke engine, 20-inch guide bar and chain, automatic chain oiler, inertia-activated chain brake, anti-vibration handles, decompression valve for easy starting, side-access chain tensioner.

Safety Information

Read and understand all instructions before operation. Always wear proper PPE.

1. Personal Protective Equipment (PPE): Wear safety glasses, hearing protection, gloves, chainsaw chaps/pants, and sturdy boots.
2. Clear Work Area: Ensure no bystanders, pets, or obstacles within 15 feet.
3. Fuel Safety: Mix fuel outdoors; use approved gasoline/oil mix (50:1). Store fuel in approved container.
4. Kickback Awareness: Be aware of kickback zone (upper quadrant of bar tip). Use reduced-kickback chain.
5. Carrying & Transport: Engage chain brake; carry with bar pointed rearward.

WARNING! Chainsaws are dangerous tools. Failure to follow safety instructions can result in serious injury or death. Never operate when tired or under the influence.

Assembly & Setup

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

1. Attach Guide Bar & Chain: Place bar on studs, loop chain around sprocket and bar with cutters facing forward on top. Adjust tension.
2. Fill Bar & Chain Oil: Use recommended bar & chain oil. Fill to MAX line on oil tank.
3. Prepare Fuel Mix: Use fresh unleaded gasoline (89 octane min.) mixed with 2-stroke oil at 50:1 ratio. Shake well.
4. Fill Fuel Tank: Add fuel mix to fuel tank. Avoid spills; wipe up immediately.
5. Check All Fasteners: Ensure bar nuts, side cover screws, and handles are secure.

CAUTION! Always perform assembly on a clean, flat surface with the spark plug disconnected.

Specifications

• Model: Craftsman 20" 50cc Chainsaw
• Engine Type: 2-stroke, single cylinder, air-cooled
• Displacement: 50 cc
• Power Output: 3.5 HP
• Max Engine Speed: 13,500 RPM
• Fuel/Oil Ratio: 50:1 (unleaded gasoline to 2-stroke oil)
• Ignition System: Electronic, capacitor discharge
• Starting System: Recoil with decompression valve
• Chain Brake: Inertia-activated, manual release
• Recommended Bar Lengths: 18" - 20"
• Warranty: 2-year limited warranty

Controls and Components

Main Controls: Front Handle with throttle trigger and lockout; Rear Handle with On/Stop switch; Choke/Primer; Decompression Valve; Chain Brake Lever; Side-Access Chain Tensioner.

Operation Sequence: Set On/Stop switch to ON. Engage choke (cold start). Pull decompression valve. Pull starter rope until engine 'pops'. Disengage choke. Pull starter rope to start. Squeeze throttle trigger to operate.

Chain Brake: Push forward to engage (stops chain). Pull back toward operator to disengage. Test before each use.

Operation Instructions

Starting (Cold Engine):

1. Place saw on flat ground, clear of debris.
2. Engage chain brake.
3. Move On/Stop switch to ON.
4. Fully engage choke lever.
5. Press decompression valve (if equipped).
6. Pull starter rope briskly 3-5 times until engine 'pops'.
7. Disengage choke to half or run position.
8. Pull starter rope again to start.
9. Allow 30-second warm-up at idle.

Cutting Techniques: Use lower quadrant of bar for cutting. Let saw do the work; avoid forcing. For felling, plan escape path. Use wedges for bucking large logs.

Tip: Keep chain sharp and properly tensioned. A dull chain increases kickback risk and operator fatigue.

Chain & Bar Maintenance

Regular maintenance ensures optimal performance and safety.

1. Chain Sharpening: Use round file and guide. Maintain 30° filing angle. File all cutters evenly.
2. Chain Tension: Check when cold. Proper tension: snug against bar but pullable by hand. Adjust via side tensioner.
3. Bar Maintenance: Clean bar grooves weekly. Flip bar monthly for even wear. Check for wear (hooked rails).
4. Sprocket Inspection: Check drive sprocket for wear; replace if teeth are hooked or worn.
5. Oiler Test: Run saw at high RPM pointed at light surface; look for oil line.

WARNING! Always wear heavy gloves when handling chain. Disconnect spark plug before maintenance.

Engine Maintenance

Air Filter: Clean weekly (more in dusty conditions). Remove, tap clean, or wash with soapy water. Dry completely before reinstalling.

Spark Plug: Check gap (0.025 in / 0.63 mm). Clean electrode with wire brush. Replace annually or if fouled.

Fuel System: Use fresh fuel mix. Empty tank and run dry for storage over 30 days. Clean fuel filter annually.

Carburetor Adjustment: Factory set. Only adjust if necessary (high altitude). Refer to service manual.

Storage Guidelines

For storage over 30 days:

1. Empty fuel tank and run engine until it stops.
2. Remove spark plug, add 1 teaspoon of 2-stroke oil into cylinder. Pull starter rope slowly 2-3 times to coat. Reinstall plug.
3. Clean entire saw, especially cooling fins and air filter.
4. Remove chain, clean, and soak in oil. Store bar and chain separately.
5. Store in dry, cool place, protected from dust and moisture.

CAUTION! Never store with fuel in tank for extended periods. Fuel degrades and can damage carburetor.

Warranty Information

Craftsman 20 50cc Chainsaw is covered by a 2-year limited warranty from date of purchase against defects in materials or workmanship. Warranty does not cover normal wear, misuse, neglect, improper maintenance, or use of non-genuine parts. Proof of purchase required. For warranty service, contact Craftsman Customer Support at 1-888-331-4569 or visit www.craftsman.com.

Troubleshooting

Service: For repairs beyond basic maintenance, contact authorized Craftsman service center. 1-888-331-4569; www.craftsman.com