550 Chainsaw Manual

The 550 Chainsaw is a professional-grade power tool designed for heavy-duty cutting applications. This manual covers the 55cc engine model with features including automatic chain oiling, anti-vibration system, chain brake, decompression valve, and electronic ignition. Below are key sections for safety, features, operation, maintenance, and troubleshooting.

Features at a Glance

Key components: 55cc 2-stroke engine, 20-inch guide bar, automatic oiling system, inertia-activated chain brake, decompression valve, anti-vibration handles.

Feature	Description
Engine displacement	55cc 2-stroke air-cooled engine
Guide bar length	20 inches (standard)
Chain pitch	3/8 inch
Fuel capacity	0.55 liters
Oil capacity	0.26 liters
Weight (without bar/chain)	5.9 kg
Ignition system	Electronic CDI
Chain brake	Inertia-activated safety feature
Vibration reduction	Multi-point anti-vibration system
Starting system	Decompression valve for easier starting

Safety Instructions

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

1. Inspect chainsaw before each use: Check chain tension, sharpness, and lubrication.
2. Clear work area: Remove tripping hazards and ensure safe escape routes.
3. Proper stance: Stand with feet shoulder-width apart, firm grip with both hands.
4. Kickback prevention: Keep nose of bar away from obstructions; use reduced-kickback chain.

WARNING! Never operate chainsaw above shoulder height or with one hand. Always keep bystanders at least 15 feet away.

Assembly & Setup

Unpack and inspect all components. Assembly requires basic tools.

1. Attach guide bar: Loosen bar nuts, position bar over 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 hand-tight, adjust tension screw until chain snaps back when pulled.
4. Final tightening: Tighten bar nuts securely after proper tension is set.
5. Fuel mix: Use 50:1 gasoline to 2-stroke oil ratio (89 octane minimum).

CAUTION! Chain must move freely when pulled; overtightening causes damage and overheating.

Specifications

• Engine Type: 2-stroke, single cylinder, air-cooled.
• Displacement: 55cc.
• Power Output: 3.2 kW (4.3 hp).
• Maximum RPM: 13,500.
• Idle Speed: 2,800 RPM.
• Fuel: Regular unleaded gasoline (89 octane minimum) with 2-stroke oil.
• Oil: Bar and chain oil (ISO viscosity grade 30 or equivalent).
• Spark Plug: NGK BPMR7A (gap 0.5mm).
• Sound Level: 105 dB(A) at operator's ear.
• Warranty: 2 years commercial use, 5 years consumer use.

Controls and Components

Main controls: Front handle with throttle trigger, rear handle with throttle lockout, choke control, stop switch, chain brake lever.

Components: 1. Air filter cover, 2. Fuel tank cap, 3. Oil tank cap, 4. Decompression valve, 5. Chain tensioning screw, 6. Spark plug, 7. Muffler, 8. Chain catcher, 9. Hand guard, 10. Anti-vibration mounts.

Operation: Pull choke for cold start, push choke off after engine fires. Throttle lockout must be depressed before throttle trigger engages. Chain brake activates automatically upon kickback or manually by pushing hand guard forward.

Operation Guide

Starting procedure: Place on flat surface, engage chain brake, set choke, pull starter cord.

1. Cold start: Set choke to full, pull starter 3-5 times until engine fires.
2. Warm start: Choke off, pull starter 1-3 times.
3. Cutting technique: Let chain do the work, avoid forcing, maintain steady RPM.
4. Bucking: Support log properly, cut from top down, watch for binding.
5. Limbing: Work from trunk outward, keep body to side of cutting path.
6. Felling: Plan escape path, make notch cut first, then back cut leaving hinge.

Tip: Keep chain sharp - dull chains require more force and increase kickback risk.

Maintenance Schedule

Daily: Check chain tension, sharpness, lubrication. Clean air filter, check fuel/oil levels.

1. Every 10 hours: Clean spark arrestor screen, check bar for wear.
2. Every 25 hours: Replace air filter, clean cooling fins, check all fasteners.
3. Every 50 hours: Replace spark plug, clean carburetor air passage.
4. Every 100 hours: Clean fuel filter, check fuel lines, decarbonize exhaust.
5. Seasonal: Replace fuel filter, inspect anti-vibration mounts, professional tune-up.

WARNING! Always disconnect spark plug wire before performing maintenance. Use only genuine replacement parts.

Chain & Bar Care

Proper maintenance extends chain and bar life significantly.

Chain sharpening: Use round file matching chain pitch (5/32" for 3/8" chain). Maintain 30° cutting angle, 10° top plate angle. File each cutter equally.

Bar maintenance: Flip bar weekly for even wear. Clean bar groove regularly. Dress bar rails with flat file when burrs develop.

Lubrication: Always use proper bar and chain oil. Check oil flow by pointing bar at light surface - should see oil line.

Storage Guidelines

Proper storage prevents fuel system issues and corrosion.

1. Short-term (under 30 days): Fill fuel tank to prevent condensation.
2. Long-term: Drain fuel completely, run engine until it stops. Remove spark plug, add 1 teaspoon of oil through spark plug hole, pull starter slowly to distribute.
3. Clean entire saw, especially cooling fins and air filter.
4. Loosen chain tension, store in dry place away from moisture.
5. Cover to prevent dust accumulation.

CAUTION! Never store with fuel in tank for more than 30 days - modern ethanol-blended fuels degrade and damage fuel system components.

Warranty Information

2-year commercial warranty, 5-year consumer warranty from date of purchase. Warranty covers defects in materials and workmanship. Not covered: normal wear, improper maintenance, accident damage, use of non-genuine parts, commercial rental use. Keep original receipt as proof of purchase. For warranty service, contact authorized service center with model and serial numbers.

Troubleshooting

Symptom	Possible Cause	Corrective Action
Engine won't start	No spark/flooded/old fuel	Check spark plug; wait if flooded; use fresh fuel mix.
Engine starts then dies	Clogged fuel filter/carburetor	Replace fuel filter; clean carburetor.
Poor performance	Dirty air filter/clogged muffler	Clean/replace air filter; clean spark arrestor screen.
Chain won't turn	Brake engaged/chain too tight	Disengage chain brake; adjust chain tension.
Excessive vibration	Loose components/worn mounts	Tighten all fasteners; replace anti-vibration mounts.
Chain throws oil	Over-oiling/incorrect oil	Adjust oiler; use proper bar and chain oil.
Chain dulls quickly	Cutting dirty wood/improper filing	Avoid ground contact; sharpen correctly.

Service: For technical support, contact 1-800-555-CHAINSAW or visit www.chainsaw550manual.com