DeWalt X548 Lawn Mower Manual

The DeWalt X548 is a powerful 21-inch self-propelled gas lawn mower featuring a 190cc Briggs & Stratton engine, 3-in-1 mulching/bagging/side-discharge capability, 6-position single-lever height adjustment (1.5"-4"), rear-wheel drive with variable speed control, durable steel deck, easy-pull recoil start, and large 2.5-bushel rear bag. Below are key sections for safety, features, assembly, operation, maintenance, and troubleshooting.

1. Features at a Glance 2. Assembly Instructions 3. First-Time Operation 4. Specifications 5. Controls and Settings 6. Cutting & Discharge Options 7. Maintenance Schedule 8. Storage & Winterization 10. Safety Information 11. Warranty & Support 12. Troubleshooting

Features at a Glance

Key components: 190cc Engine, Steel Cutting Deck, Rear Bag, Height Adjustment Lever, Drive Control Bar, Recoil Starter.

FeatureDescription
Engine190cc Briggs & Stratton 850 Series, OHV
Cutting Width21 inches
Cutting Height6-position adjustment (1.5" to 4")
Drive SystemSelf-propelled rear-wheel drive
Speed ControlVariable speed lever on handle
Discharge Options3-in-1: Mulch, Bag, Side-discharge
Bag Capacity2.5 bushels (rear)
StarterRecoil pull-start
Deck MaterialPowder-coated steel
Wheels8-inch rear, 7-inch front

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 wing nuts.
  2. Install Upper Handle: Connect upper handle section, tighten all fasteners securely.
  3. Attach Bag: Hang rear bag assembly on bag hooks; ensure clips engage properly.
  4. Install Discharge Chute: For side-discharge, attach chute to deck opening.
  5. Add Oil & Gas: Fill engine with SAE 30 oil (20 oz) and unleaded gasoline (check level).

WARNING! Do not add gasoline during assembly or near open flames. Ensure all fasteners are tight before operation.

First-Time Operation

Before starting, perform pre-operation checks.

  1. Check Oil & Fuel: Ensure proper levels (oil dipstick, gas tank).
  2. Set Cutting Height: Adjust lever to desired position (start at 3" for first mow).
  3. Select Discharge Mode: Install appropriate plug for mulch, bag, or side-discharge.
  4. Start Engine: Set throttle to FAST, pull recoil starter firmly.
  5. Engage Drive: Squeeze drive control bar against handle to move forward.

CAUTION! Clear mowing area of debris. Never operate without proper discharge attachment installed.

Specifications

Controls and Settings

Handle Controls: Drive Control Bar, Speed Control Lever, Height Adjustment Lever.

Engine Controls: Throttle (FAST/SLOW/STOP), Choke, Recoil Starter.

Height Adjustment: Single lever adjusts all four wheels simultaneously (positions 1-6). Drive System: Squeeze drive bar to engage wheels; adjust speed with lever. Discharge Selection: Mulch plug, bag, or side-discharge chute must be properly installed.

Cutting & Discharge Options

3-in-1 system allows mulching, bagging, or side-discharge.

  1. Mulching: Install mulch plug; grass clippings are cut finely and returned to lawn.
  2. Bagging: Attach rear bag; collects clippings for disposal.
  3. Side-Discharge: Install discharge chute; ejects clippings to side (right).

Tip: For best results, never cut more than 1/3 of grass height at once. Keep blades sharp.

Maintenance Schedule

Regular maintenance ensures optimal performance and longevity.

  1. Before Each Use: Check oil level, inspect blade for damage, clear deck of debris.
  2. Every 25 Hours: Change engine oil (or seasonally).
  3. Every Season: Replace air filter, spark plug.
  4. As Needed: Sharpen or replace blade (balance after sharpening).
  5. Periodically: Check wheel bolts, handle fasteners, drive cable tension.

WARNING! Disconnect spark plug wire before performing any maintenance. Allow engine to cool completely.

Storage & Winterization

Proper storage prevents fuel system issues.

  1. Add Fuel Stabilizer: Run engine 5 minutes to circulate treated fuel through system.
  2. Drain or Run Dry: Either drain fuel tank and carburetor, or run engine until it stops.
  3. Change Oil: Replace oil at end of season.
  4. Clean Thoroughly: Remove grass/debris from deck, undercarriage, and engine.
  5. Store Indoors: Keep in dry, covered location; protect from moisture.

CAUTION! Never store with untreated gasoline in tank; it will degrade and clog carburetor.

Safety Information

Read and understand all safety instructions before operation.

DANGER! Rotating blade can cause severe injury. Always disconnect spark plug before servicing.

Warranty & Support

DeWalt X548 comes with a 3-year limited warranty for residential use. Proof of purchase required. Warranty covers defects in materials/workmanship; does not cover normal wear, misuse, or lack of maintenance. For support, visit www.dewalt.com or contact 1-800-4-DeWalt (1-800-433-9258). Register your product online for faster service.

Troubleshooting

SymptomPossible CauseCorrective Action
Engine won't startNo fuel, old gas, spark plugCheck fuel level; use fresh gas; inspect/replace spark plug.
Engine runs poorlyDirty air filter, old gasClean/replace air filter; drain and refill with fresh gasoline.
Uneven cutDull blade, uneven tire pressureSharpen or replace blade; check tire pressure (all equal).
Loss of powerClogged deck, dirty filterClean underside of deck; check/clean air filter.
Drive not engagingDrive cable loose, belt wornAdjust drive cable tension; inspect drive belt for wear.
Excessive vibrationLoose blade, bent bladeTighten blade bolt; replace bent/damaged blade.

Reset: For engine with safety switch, ensure all controls are in proper start position.

Service: 1-800-4-DeWalt; www.dewalt.com

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