Homelite 3850 Chainsaw Manual

The Homelite 3850 is a professional-grade gasoline-powered chainsaw designed for demanding cutting tasks. It features a high-performance 38cc 2-stroke engine, an 18-inch Oregon bar and chain, automatic oiling system, anti-vibration handles, inertia chain brake, and easy-start technology. Below are key sections for safety, features, assembly, operation, maintenance, and troubleshooting.

Features at a Glance

Key components: 38cc 2-stroke engine, 18-inch Oregon bar and chain, automatic chain oiler, anti-vibration system, inertia-activated chain brake, decompression valve, and translucent fuel tank.

Safety Information

Read all instructions before operation. Always wear protective gear.

1. Personal Protective Equipment (PPE): Wear 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. Work Area Safety: Clear area of bystanders, especially children. Maintain secure footing.
4. Kickback Awareness: Hold saw firmly with both hands. Do not cut with tip of bar.

WARNING! Gasoline is highly flammable. Refuel in well-ventilated area with engine off and cool. Never smoke near fuel.

Assembly & Setup

Unpack and inspect contents. Assemble bar and chain.

1. Attach Guide Bar: Place bar over studs, align chain with sprocket, tensioning pin in bar hole.
2. Install Chain: Fit chain over bar, ensuring cutting teeth face forward on top.
3. Adjust Chain Tension: Loosen bar nuts, turn tensioning screw until chain snaps back when pulled from bar.
4. Tighten Bar Nuts: Secure bar nuts while lifting tip of bar.
5. Fill Fluids: Add fuel mix to fuel tank and bar & chain oil to oil tank.

CAUTION! Chain must be properly tensioned. Loose chain can derail; overtightened chain can damage bar or engine.

Specifications

• Engine: 38cc 2-stroke, single cylinder, air-cooled.
• Power Output: 2.1 HP at 9,500 RPM.
• Fuel: Unleaded gasoline (89 octane min.) mixed with 2-cycle oil at 40:1 ratio.
• Bar Length: 18 inches (45 cm).
• Chain Speed: Max 55 ft/sec (16.8 m/sec).
• Ignition: CDI electronic.
• Starting System: Recoil with decompression valve.
• Sound Level: 112 dB(A) at operator's ear.
• Vibration Level: 4.2 m/s² front handle, 6.1 m/s² rear handle.
• Warranty: 2-year limited warranty for home use.

Controls and Components

Main controls: Throttle trigger, throttle trigger lockout, stop switch, choke control, decompression valve, chain brake lever, primer bulb.

Right Side: Throttle trigger, throttle lockout, front handle. Left Side: Chain brake lever, choke control, decompression valve, stop switch. Top: Primer bulb, air filter cover. Rear: Rear handle with trigger lock.

Chain Brake: Push forward manually or activates automatically during kickback. Decompression Valve: Reduces compression for easier starting. Primer Bulb: Press 5-6 times to prime engine when cold.

Fuel & Oil Mixing

Use 40:1 fuel/oil ratio. Mix in separate container before filling.

1. Use fresh unleaded gasoline (89 octane minimum).
2. Add high-quality 2-cycle engine oil (ISO-L-EGD, JASO FD).
3. For 1 gallon gasoline: Add 3.2 oz oil. For 5 liters gasoline: Add 100 ml oil.
4. Shake mixture thoroughly.
5. Fill fuel tank, avoiding spills. Clean any spilled fuel immediately.

Tip: Use fuel stabilizer if storing over 30 days. Never use automotive oil or straight gasoline.

Starting & Operation

Starting procedure for cold and warm engine.

1. Cold Start: Set chain brake ON. Move stop switch to RUN. Pull choke knob out. Press primer bulb 5-6 times. Place on ground, hold rear handle with right foot. Pull starter rope briskly until engine fires. Push choke knob in. Pull starter rope until engine starts.
2. Warm Start: Follow above but do not use choke or primer.
3. Operation: Release chain brake. Squeeze throttle trigger lockout and throttle to increase RPM. Allow engine to warm up 30 seconds before cutting.
4. Cutting Techniques: Use lower part of bar. Let saw do the work; don't force. Beware of pinch points.
5. Stopping: Release throttle, allow engine to idle. Press stop switch to OFF.

WARNING! Always engage chain brake when starting, carrying, or not actively cutting. Keep both hands on handles during operation.

Chain Maintenance

Regular maintenance ensures optimal performance and safety.

1. Chain Sharpening: Use round file matching chain pitch (5/32" for .325"). Maintain 30° cutting angle. File each tooth equally.
2. Depth Gauge Setting: File depth gauges with flat file when sharpening. Maintain 0.025" clearance.
3. Chain Tension: Check frequently when new. Proper tension: chain should snap back when pulled from bar.
4. Bar Maintenance: Clean bar groove weekly. Flip bar monthly for even wear.
5. Sprocket Inspection: Replace drive sprocket if worn (typically every 2-3 chains).

CAUTION! Wear heavy gloves when handling chain. Always stop engine and disconnect spark plug before maintenance.

Storage & Winterization

Proper storage prevents fuel system damage.

1. Drain fuel tank and run engine until it stops.
2. Remove spark plug, add 1 teaspoon of oil through spark plug hole. Pull starter rope slowly to distribute oil.
3. Clean entire saw, especially air filter and cooling fins.
4. Remove chain, clean and soak in oil. Store bar coated with oil.
5. Store in dry, cool place away from children.

Tip: Use fuel stabilizer if unable to drain fuel. Run engine 5 minutes to circulate stabilized fuel.

Warranty Information

Homelite 3850 comes with 2-year limited warranty for home use (90 days for commercial use). Warranty covers defects in materials and workmanship. Not covered: normal wear, misuse, improper maintenance, accidental damage. Keep purchase receipt for warranty claims. For service, contact authorized Homelite service centers. For support, visit www.homelite.com or call 1-800-242-4672.

Troubleshooting

Spark Plug: NGK BPMR7A, gap 0.020" (0.5 mm). Replace annually.

Service: 1-800-242-4672; www.homelite.com