Ryobi P542 Chainsaw Manual

The Ryobi P542 is a 42cc 2-cycle gas-powered chainsaw designed for general cutting, pruning, and firewood preparation. It features an automatic oiler, anti-vibration system, tool-less chain tensioning, and a 16-inch Oregon bar and chain. Below are key sections for safety, features, assembly, operation, maintenance, and troubleshooting.

Features at a Glance

Key components: 42cc 2-cycle engine, 16-inch Oregon bar and chain, automatic chain oiler, anti-vibration handles, tool-less chain tensioning, inertia chain brake, decompression valve, and translucent fuel tank.

Safety Information

Read all instructions before use. Wear appropriate PPE.

1. Always wear safety glasses, hearing protection, gloves, chainsaw chaps, and sturdy boots.
2. Keep bystanders and pets at least 15 feet away.
3. Never operate above shoulder height or on a ladder.
4. Use proper grip: left hand on front handle, right hand on rear handle.
5. Be aware of kickback zone; never cut with tip of bar.

WARNING! Gasoline is flammable; refuel in well-ventilated area with engine off and cool. Avoid contact with hot muffler.

Assembly & Setup

Unpack and inspect contents. Assemble bar and chain.

1. Attach bar and chain: Place chain over sprocket, align bar studs, tighten nuts finger-tight.
2. Tension chain: Use tool-less adjuster to raise bar tip; tighten until chain snaps back when pulled.
3. Final tighten: Secure bar nuts with combination wrench.
4. Fill oil tank: Use bar and chain oil (not motor oil).
5. Mix fuel: Use 50:1 gas/oil mix (2.6 oz of 2-cycle oil per 1 gallon of unleaded gasoline).

CAUTION! Ensure chain is properly tensioned—too loose may derail; too tight may damage bar.

Specifications

• Engine Displacement: 42cc
• Engine Type: 2-cycle, air-cooled
• Fuel/Oil Ratio: 50:1 (2.6 oz oil per 1 gal gas)
• Bar Length: 16 inches
• Chain Pitch: 3/8" low-profile
• Chain Gauge: 0.050"
• Oil Capacity: Approx. 8.5 fl oz
• Fuel Capacity: Approx. 13.5 fl oz
• Weight: 10.8 lbs (dry)
• Sound Level: 106 dB(A) at operator's ear

Controls and Components

Main components: Throttle trigger, throttle lockout, choke, ON/OFF switch, decompression valve, primer bulb, chain brake, front/rear handles, fuel cap, oil cap.

Starting Procedure:

1. Place on flat, clear surface.
2. Engage chain brake by pushing forward.
3. Set ON/OFF switch to ON.
4. Pull choke to FULL position (cold start).
5. Press decompression valve (if equipped).
6. Press primer bulb 5-6 times.
7. Pull starter rope briskly until engine fires.
8. Push choke to HALF, pull until engine runs.
9. Disengage chain brake before cutting.

Fuel & Oil

Use fresh unleaded gasoline (87 octane minimum) mixed with 2-cycle oil.

1. Mix fuel in approved container: 1 gallon gas + 2.6 oz 2-cycle oil (50:1).
2. Shake gently before filling.
3. Fill fuel tank to 80% capacity to allow for expansion.
4. Use bar and chain oil in oil reservoir; check level frequently.
5. Clean area around caps before opening.

Tip: Use fuel stabilizer if storing more than 30 days. Never use automotive motor oil or dirty oil.

Operation

Supports felling, limbing, bucking, and pruning.

1. Starting: Follow cold/hot start procedure above.
2. Warm-up: Allow 30-60 seconds at idle before cutting.
3. Cutting: Apply light pressure; let chain do the work.
4. Kickback prevention: Hold firmly, avoid tip contact, maintain high chain speed.
5. Automatic oiler: Adjust flow via screw near oil cap if needed.
6. Stop: Release throttle, engage chain brake, turn OFF switch.

WARNING! Never operate with one hand. Always plan escape path when felling trees.

Chain Maintenance

Keep chain sharp and properly tensioned.

1. Sharpening: Use round file (5/32") and file guide; maintain 30° angle.
2. Tension: Check when cold; adjust tool-less knob as needed.
3. Cleaning: Remove debris from bar groove and oil holes.
4. Rotation: Flip bar periodically for even wear.
5. Inspection: Check for damaged or worn drive links, rivets, and cutters.

CAUTION! Wear heavy gloves when handling chain. Replace if cutters are damaged or excessively worn.

Storage

Prepare for storage if not used for 30+ days.

1. Drain fuel tank or add fuel stabilizer and run for 2 minutes.
2. Run carburetor dry by disconnecting fuel line and letting engine stall.
3. Remove chain, clean, and soak in oil; store bar coated with oil.
4. Clean exterior; store in dry, secure location.
5. Cover to prevent dust accumulation.

CAUTION! Store fuel in approved container away from heat sources and out of reach of children.

Warranty Information

Ryobi P542 includes a 2-year limited warranty covering defects in materials and workmanship. Proof of purchase required. Warranty does not cover normal wear, misuse, improper maintenance, or use of non-genuine parts. For warranty service, contact authorized service center or call 1-800-525-2579. Register product online at www.ryobitools.com.

Troubleshooting

Service: For technical support, call 1-800-525-2579 or visit www.ryobitools.com.