McCulloch 650 Chainsaw Manual

The McCulloch 650 is a professional-grade chainsaw featuring a powerful 65cc engine, automatic oiling system, anti-vibration handles, and a 20-inch guide bar. Designed for demanding cutting tasks, it includes safety features like a chain brake and throttle lockout. Below are key sections for safety, features, assembly, operation, maintenance, and troubleshooting.

Features at a Glance

Key components: 65cc 2-stroke engine, 20-inch guide bar, automatic chain oiler, anti-vibration system, chain brake, side-access chain tensioner.

Safety Information

Always wear proper PPE: helmet, eye protection, 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. Use proper starting technique: secure footing, engage chain brake.
5. Maintain secure grip with both hands during operation.

WARNING! Chainsaws are dangerous tools. Failure to follow safety instructions can result in serious injury or death. Read and understand all safety warnings before operation.

Assembly & Setup

Unpack and inspect contents. Assemble on clean, flat surface.

1. Attach guide bar: Remove side cover, align bar with sprocket, install chain with cutters facing forward.
2. Adjust chain tension: Loosen nuts, turn tensioner screw until chain snaps back when pulled from bar.
3. Fill fuel: Use fresh 50:1 gas/oil mixture (89 octane minimum).
4. Fill bar oil: Use quality chainsaw bar oil.
5. Prime engine: Press primer bulb 5-6 times until fuel is visible.

CAUTION! Ensure chain brake is engaged during assembly. Keep hands away from sharp chain.

Specifications

• Engine: 65cc 2-stroke, air-cooled.
• Power Output: 4.2 HP at 9,500 RPM.
• Fuel: 50:1 gas/oil mix (89+ octane).
• Bar Length: 20 inches (16" and 24" optional).
• Chain: .325 pitch, .063 gauge, 72 drive links.
• Weight: 14.5 lbs (without bar and chain).
• Sound Level: 105 dB(A) at operator's ear.
• Vibration: Front handle 4.2 m/s², Rear handle 3.8 m/s².
• Warranty: 2 years commercial, 5 years residential.

Controls and Operation

Main controls: Throttle trigger, throttle lockout, choke, primer bulb, stop switch, chain brake handle.

Starting Procedure:

1. Engage chain brake by pushing handle forward.
2. Set choke to full position (cold start).
3. Press primer bulb 5-6 times.
4. Place on ground, secure with foot in handle.
5. Pull starter cord briskly until engine fires.
6. Move choke to half position, pull until starts.
7. Blip throttle to disengage fast idle.

Cutting Techniques: Use lower quadrant of bar for cutting. Let saw do the work - don't force. Watch for kickback zone (upper tip).

Chain & Bar Maintenance

Check chain tension frequently - proper tension when chain snaps back to bar.

1. Sharpen chain: Use round file matching chain pitch (5/32" for .325).
2. File at 30° angle, maintain consistent pressure.
3. Rotate bar regularly to ensure even wear.
4. Clean bar groove and oil holes weekly.
5. Replace chain when cutters are worn to 0.25 inches.

Tip: Keep chain sharp - dull chains cause kickback and strain engine.

Engine Maintenance

Regular maintenance ensures optimal performance and longevity.

1. Air filter: Clean weekly with soap and water, replace when damaged.
2. Spark plug: Clean and gap to 0.025" every 25 hours, replace annually.
3. Cylinder fins: Keep clean for proper cooling.
4. Carburetor adjustment: Use H and L screws for idle and high-speed tuning.
5. Fuel filter: Replace every 50 hours or when clogged.

WARNING! Allow engine to cool completely before performing maintenance. Disconnect spark plug wire when working near cutting components.

Fuel & Oil

Use fresh fuel mixture (less than 30 days old).

• Fuel Mix: 50:1 ratio - 2.6 oz of 2-stroke oil per gallon of gasoline.
• Gasoline: 89 octane minimum, ethanol-free recommended.
• Bar Oil: Use quality chainsaw bar oil (viscosity adjusts to temperature).
• Winter Operation: Use winter-grade bar oil below 40°F.

CAUTION! Never use straight gasoline or automotive motor oil. Store fuel in approved containers away from heat sources.

Storage

Prepare chainsaw for storage if not used for 30+ days.

1. Drain fuel tank and run engine until it stops.
2. Remove spark plug, add 1 teaspoon of oil through spark plug hole.
3. Pull starter cord slowly to distribute oil.
4. Clean entire saw, especially air intake and cooling fins.
5. Store in dry place, bar and chain lightly oiled.

CAUTION! Never store with fuel in tank - fuel degrades and damages carburetor.

Warranty Information

McCulloch 650 Chainsaw Warranty: 2-year commercial warranty, 5-year residential warranty. Warranty covers defects in materials and workmanship. Not covered: normal wear, misuse, improper maintenance, accidental damage. For warranty service, contact authorized McCulloch service center with proof of purchase. For support, visit www.mcculloch.com or contact 1-800-521-5102.

Troubleshooting

Service Intervals: Air filter - clean weekly; Spark plug - check every 25 hours; Fuel filter - replace every 50 hours.

Technical Support: 1-800-521-5102; www.mcculloch.com