McCulloch EM450S Chainsaw Manual

The McCulloch EM450S is a 45cc, 2-stroke gasoline-powered chainsaw designed for general-purpose cutting, pruning, and felling of small to medium trees. 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: 45cc 2-stroke engine, 16-inch Oregon bar and chain, Automatic chain oiler, Anti-vibration system, Tool-less chain tensioning, Inertia chain brake, Side-access chain tensioner, Transparent fuel tank.

Safety Information

Read all instructions before use. Always wear appropriate PPE.

1. Personal Protective Equipment (PPE): Always wear safety glasses, hearing protection, gloves, chainsaw chaps/pants, and steel-toe boots.
2. Pre-Operation Check: Inspect chain sharpness, tension, and lubrication. Check for loose parts or damage.
3. Operating Area: Ensure clear work area, stable footing, and no bystanders within 15 feet.
4. Kickback Awareness: Be aware of kickback zone (upper quadrant of bar nose). Never cut with the tip.

WARNING! Chainsaws are dangerous tools. Failure to follow safety instructions can result in serious injury or death. Keep hands away from moving chain. Always engage chain brake when not cutting.

Assembly & First Use

Unpack and inspect all parts. Assemble bar and chain, fill with fuel/oil mix.

1. Attach Guide Bar & Chain: Loosen bar nuts, fit chain over sprocket and bar, align drive links, tighten bar nuts finger-tight.
2. Tension Chain: Use side tensioner wheel to adjust until chain snaps back when pulled from bar. Tighten bar nuts securely.
3. Fill Fuel: Use fresh 50:1 gasoline to 2-stroke oil mix. Do not use old or ethanol-blended fuel if possible.
4. Fill Chain Oil: Use proper bar and chain oil. Check oiler operation before starting.
5. Starting Procedure: Place on flat surface, set choke, pull starter cord until engine fires, set to half-choke, pull again to start.

CAUTION! Fuel is highly flammable. Refuel in well-ventilated area with engine off and cool. Wipe spills immediately.

Specifications

• Model: McCulloch EM450S
• Engine Type: 2-stroke, single cylinder, air-cooled
• Displacement: 45 cc
• Power Output: 2.2 kW (3.0 hp)
• Fuel/Oil Mix: 50:1 (Unleaded gasoline to 2-stroke oil)
• Bar Length: 16 inches (40 cm)
• Chain Pitch: .325 inches
• Drive Links: 72
• Weight (without fuel/oil): 5.2 kg (11.5 lbs)
• Sound Pressure Level: Approx. 110 dB(A)
• Vibration Level: Front handle: 4.5 m/s², Rear handle: 6.5 m/s²

Controls and Components

Main controls located on top and rear handle.

Top Handle: Throttle trigger, Throttle trigger lockout, Chain brake lever, Choke control, Stop switch.

Rear Handle: Starter grip, Fuel tank cap, Oil tank cap, Decompression valve (if equipped).

Side Panel: Tool-less chain tensioner wheel, Bar nut covers.

Chain Brake: Engages automatically via inertia or manually by pushing handle forward. Stops chain within milliseconds.

Operation

Starting, cutting techniques, and shutdown.

1. Starting Cold Engine: Engage chain brake. Set choke to full. Pull starter cord 3-4 times until engine 'pops'. Set choke to half. Pull to start. Warm up for 30 seconds.
2. Starting Warm Engine: No choke. Pull starter cord.
3. Cutting: Use full throttle when cutting. Let chain do the work; do not force. Be aware of pinch points, especially when felling.
4. Kickback Prevention: Maintain firm grip, stand to side, never cut above shoulder height, avoid tip contact.
5. Shutdown: Release throttle, allow idle for 10 seconds, press stop switch.

Tip: Practice cutting on small logs on a sawhorse before attempting larger tasks.

Chain & Bar Maintenance

Regular maintenance ensures performance and safety.

1. Chain Sharpening: Use round file (4.0mm / 5/32") and file guide. Maintain 30° cutting angle. File all cutters evenly.
2. Chain Tension: Check frequently when new. Chain should be snug against bar but pull freely. Adjust when engine is OFF and cool.
3. Bar Maintenance: Clean bar groove regularly. Flip bar weekly for even wear. Dress bar rails with flat file if burred.
4. Lubrication: Always use bar and chain oil. Check oiler output by pointing tip at light surface and running at full throttle (briefly). Oil should fling off.

WARNING! Always wear heavy gloves when handling chain. A sharp chain is safer than a dull one as it requires less force.

Engine Maintenance

Air filter, spark plug, and fuel system care.

1. Air Filter: Clean weekly in soapy water, dry completely. Replace if torn or excessively dirty.
2. Spark Plug: Check gap (0.020" / 0.5mm). Clean with wire brush. Replace annually or if fouled.
3. Fuel Filter: Replace yearly or if clogged.
4. Carburetor Adjustment: Factory set. Only adjust if necessary (high idle, poor performance). Refer to service manual.
5. Cylinder Fins: Keep cooling fins clean for proper engine cooling.

CAUTION! Disconnect spark plug wire before performing any maintenance to prevent accidental starting.

Storage

Prepare chainsaw for long-term storage.

1. Drain all fuel from tank and carburetor by running engine until it stops.
2. Remove chain, clean, and soak in oil. Store separately.
3. Clean entire saw, especially air intake and cooling fins.
4. Store in a dry, secure place, out of reach of children.

CAUTION! Storing with fuel in the carburetor will cause varnish buildup and starting problems.

Warranty Information

McCulloch EM450S is covered by a limited warranty for residential use. Proof of purchase required. Warranty does not cover wear items (chain, bar, spark plug, air filter), damage from misuse, improper fuel, or lack of maintenance. For warranty service, contact an authorized McCulloch service center. For support, visit www.mcculloch.com or contact customer service at 1-800-521-8559.

Troubleshooting

Reset: For electronic ignition issues, disconnect spark plug wire for 1 minute to reset module.

Service: For repairs beyond basic maintenance, contact authorized service: 1-800-521-8559; www.mcculloch.com