McCulloch MS1838AV Chainsaw Manual

The McCulloch MS1838AV is an 18-inch gas-powered chainsaw featuring anti-vibration technology, automatic oiling, a 38cc 2-stroke engine, and a chain brake for enhanced safety. Designed for homeowners and DIY enthusiasts, it's suitable for cutting firewood, pruning, and general yard maintenance. This manual covers safety, assembly, operation, maintenance, and troubleshooting.

Features at a Glance

Key components: 38cc 2-stroke engine, 18-inch guide bar, automatic chain oiler, anti-vibration system, inertia-activated chain brake, side-access chain tensioner, and easy-start system.

Safety Information

Read all instructions before use. Always wear appropriate PPE.

1. Personal Protective Equipment (PPE): Safety glasses, hearing protection, gloves, chainsaw chaps, and steel-toe boots.
2. Pre-Operation Check: Inspect chain tension, sharpness, and lubrication. Ensure all fasteners are tight.
3. Operating Area: Clear work area of obstacles, bystanders, and pets. Maintain secure footing.
4. Fuel Safety: Refuel outdoors, away from ignition sources. Use fresh fuel mix (see Specifications).

WARNING! Kickback can occur without warning. Always hold saw firmly with both hands. Never operate above shoulder height or with one hand.

Assembly & First-Time Setup

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

1. Attach guide bar and chain: Loosen bar nuts, position chain on bar with cutting teeth facing forward, place bar over studs, adjust tension, then tighten nuts.
2. Fill chain oil: Use quality bar & chain oil. Fill oil tank to marked level.
3. Prepare fuel mix: Use 89+ octane gasoline and 2-stroke oil at a 40:1 ratio (3.2 oz oil per 1 gallon gas). Shake well before refueling.
4. Prime and start: Press primer bulb 5-6 times, set choke, pull starter cord until engine fires, then move choke to run position and pull again.

CAUTION! Ensure chain brake is disengaged before starting. Keep hands away from cutting area during assembly.

Specifications

• Model: McCulloch MS1838AV
• Engine Displacement: 38 cc
• Power Output: 2.0 HP
• Guide Bar Length: 18 inches
• Chain Pitch: .325 inch
• Chain Gauge: .050 inch
• Fuel Mix Ratio: 40:1 (Gasoline:2-Stroke Oil)
• Recommended Fuel: 89+ octane unleaded gasoline
• Recommended Oil: McCulloch 2-Stroke Oil or JASO FD-rated oil
• Sound Pressure Level: Approx. 110 dB(A)
• Vibration Level: Front handle: 4.5 m/s², Rear handle: 6.5 m/s²

Controls and Components

Familiarize yourself with all controls before operation.

Main Components: Front handle with chain brake, rear handle with throttle trigger, throttle lockout, choke control, primer bulb, stop switch, side-access chain tensioner, and fuel/oil caps.

Controls: - Throttle Trigger: Controls engine speed. Release to idle. - Throttle Lockout: Must be depressed to engage throttle. - Chain Brake Lever: Manually activate by pushing forward. Automatically activates on kickback. - Choke Control: Used for cold starts. - Stop Switch: Stops engine. - Primer Bulb: Pumps fuel into carburetor for easier starting.

Operation

Proper technique ensures safety and efficiency.

1. Starting: Engage chain brake. Set choke to full, press primer 5x, pull starter cord until engine pops, set choke to half, pull until started, then disengage brake.
2. Cutting: Use full throttle when cutting. Let chain do the work; do not force. Be aware of pinch points, especially when cutting logs under tension.
3. Kickback Prevention: Hold saw firmly, avoid contact with bar tip, maintain sharp chain, and always use chain brake when not cutting.
4. Stopping: Release throttle, allow engine to idle briefly, then press stop switch.

Tip: Check chain tension frequently during first 10 minutes of use as new chain stretches.

Chain & Bar Maintenance

Regular maintenance ensures optimal performance and safety.

1. Chain Sharpening: Use round file and guide. Maintain 30° cutting angle. File all cutters evenly.
2. Chain Tension: Adjust when chain sags from bar. Loosen bar nuts, adjust tensioning screw until chain snaps back when pulled from bar, then retighten nuts.
3. Bar Maintenance: Clean bar groove regularly. Flip bar weekly for even wear.
4. Lubrication: Check oil flow before each use. Chain should throw a fine mist of oil during operation.

WARNING! Always wear heavy gloves when handling chain. Ensure engine is off and cool before maintenance.

Engine Maintenance

Follow scheduled maintenance for long engine life.

• Air Filter: Clean every 5 hours of operation. Replace if damaged.
• Spark Plug: Check gap (0.025 inch) every 10 hours. Clean or replace as needed.
• Fuel Filter: Replace annually or if clogged.
• Carburetor Adjustment: Factory set. Only adjust if necessary (consult authorized service).
• Cylinder Fins: Keep clean for proper cooling.

CAUTION! Allow engine to cool completely before performing maintenance.

Storage

Proper storage prevents fuel system issues and corrosion.

1. Drain all fuel from tank and run engine until it stops to clear carburetor.
2. Remove chain, clean, and soak in oil. Clean bar and coat with oil.
3. Store in a dry, secure place, out of reach of children.
4. For long-term storage (over 30 days), consider adding fuel stabilizer to fresh fuel mix, run for 5 minutes, then drain as above.

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

Troubleshooting

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

Warranty & Support

McCulloch offers a limited warranty for residential use. Proof of purchase required.

Warranty Coverage: 2 years on powerhead, 90 days on guide bar and chain against defects in materials/workmanship.

Exclusions: Normal wear, misuse, lack of maintenance, commercial use, and use of non-genuine parts.

For Support: Contact McCulloch Customer Service at 1-800-521-2803 or visit www.mcculloch.com. For parts, visit www.mccullochparts.com.