DeWalt 12ABP3RJA39 Lawn Mower Manual

The DeWalt 12ABP3RJA39 is a 20-inch self-propelled gas lawn mower featuring a 190cc Briggs & Stratton engine, 3-in-1 mulching/bagging/side-discharge capability, single-lever height adjustment (1.5-4 inches), push-button electric start, rear-wheel drive, and a durable steel deck. Below are key sections for safety, features, assembly, operation, maintenance, and troubleshooting.

Features at a Glance

Key components: 190cc Briggs & Stratton engine, 20-inch steel cutting deck, rear bagger, mulching plug, side-discharge chute, electric start button, single-lever height adjustment, rear-wheel drive system.

Assembly Instructions

Unpack and inspect all parts. Assembly requires basic tools (included).

1. Attach handle: Align lower handle with deck brackets, secure with provided bolts and wrench.
2. Install upper handle: Connect to lower handle, tighten knobs.
3. Attach grass bag: Hook bag frame onto rear deck brackets, ensure secure latch.
4. Install side-discharge chute: Slide into opening on right side of deck, secure with wing nut.
5. Insert mulching plug: Place into rear discharge opening when mulching.
6. Add engine oil: Use SAE 30 detergent oil (approx. 20 oz) - check dipstick.
7. Add gasoline: Use fresh unleaded gasoline (87 octane minimum), no ethanol preferred.

WARNING! Do not add gasoline during assembly. Keep away from sparks or flames.

First-Time Setup

Before first use, complete final checks and safety inspection.

1. Check oil level: Ensure oil is at full mark on dipstick.
2. Check tire pressure: Inflate to 15 PSI (front and rear).
3. Inspect blade: Ensure sharpness and secure mounting (bolt torqued to 45 ft-lbs).
4. Test electric start: Connect battery (if required), press start button.
5. Adjust handle height: Loosen knobs, set to comfortable position, retighten.
6. Practice controls: Engage drive lever, test speed control, practice stopping.

CAUTION! Always wear safety glasses, long pants, and sturdy shoes during operation.

Specifications

• Model: DeWalt 12ABP3RJA39
• Engine: 190cc Briggs & Stratton 4-cycle OHV
• Cutting Width: 20 inches
• Cutting Height: 1.5 - 4 inches (6 positions)
• Drive: Self-propelled rear-wheel drive
• Start System: Electric push-button with recoil backup
• Deck Material: Powder-coated steel
• Bag Capacity: 2.5 bushels
• Fuel Capacity: 1.1 gallons
• Oil Capacity: 20 oz (SAE 30)
• Warranty: 3-year limited

Controls and Operation

Main controls located on handle. Front Panel: Electric start button, throttle control, drive engagement lever, height adjustment lever.

Operation Sequence: 1. Check oil and fuel. 2. Set cutting height. 3. Engage blade control. 4. Start engine (electric or recoil). 5. Engage drive lever to move. 6. Release drive lever to stop. 7. Disengage blade control before turning off.

Speed Control: Adjust with drive lever pressure - light pressure for slow, firm for faster. Blade Brake Clutch: Stops blade within 3 seconds when released. Fuel Shut-off: Turn valve to OFF for storage.

Cutting & Height Adjustment

Single-lever adjustment for all four wheels simultaneously.

1. Stop engine and wait for blade to stop completely.
2. Pull height adjustment lever toward wheel.
3. Move lever to desired position (1-6, lowest to highest).
4. Release lever to lock in position.
5. For best results: Cut when grass is dry; never remove more than 1/3 of grass height.
6. Cutting patterns: Overlap each pass by 2-3 inches for even cut.

Tip: Sharpen blade every 25 hours of use for optimal cutting performance.

Maintenance Schedule

Regular maintenance ensures optimal performance and longevity.

Oil Change Procedure: Run engine 5 minutes to warm oil. Turn off, disconnect spark plug. Drain oil via drain plug. Refill with 20 oz SAE 30 detergent oil.

Storage & Winterization

Proper storage prevents fuel system damage and corrosion.

1. Add fuel stabilizer: Run engine 5 minutes to circulate through system.
2. Drain or run dry: Either drain fuel tank completely or run engine until it stops.
3. Change oil: Fresh oil prevents acid buildup during storage.
4. Remove spark plug: Add 1 tablespoon of oil to cylinder, pull starter cord slowly to distribute.
5. Clean thoroughly: Remove all grass and debris from deck, wheels, and engine.
6. Store properly: Keep in dry, covered area; protect from moisture.

CAUTION! Never store with gasoline in tank without stabilizer for more than 30 days.

Safety Information

Read and understand all safety instructions before operation.

• Always wear eye protection, long pants, and sturdy shoes.
• Clear mowing area of stones, sticks, and debris.
• Never mow wet grass or in rainy conditions.
• Keep hands and feet away from rotating parts.
• Disconnect spark plug before performing maintenance.
• Never allow children to operate mower.
• Do not operate on slopes greater than 15 degrees.
• Always push mower across slopes, never up and down.

DANGER! Rotating blade can cause severe injury. Always ensure blade has stopped before crossing driveways or roads.

Warranty & Support

3-year limited warranty covering defects in materials and workmanship. Warranty does not cover normal wear, misuse, or lack of maintenance. Proof of purchase required. For warranty service, contact authorized DeWalt service center.

Customer Support: 1-800-433-9258, Monday-Friday 8am-5pm EST. Online support: www.dewalt.com. Parts diagrams and manuals available for download.

Troubleshooting

Service: For repairs beyond basic maintenance, contact authorized DeWalt service center at 1-800-433-9258.