Murray MPH550 Lawn Mower Manual

The Murray MPH550 is a 5.5 horsepower, 21-inch push lawn mower featuring a Briggs & Stratton engine, 3-in-1 mulching/bagging/side-discharge capability, single-lever height adjustment (1.5-3.75 inches), durable steel deck, easy-start system, large-capacity grass bag, and ergonomic handle with soft-grip. Below are key sections for safety, features, assembly, operation, maintenance, and troubleshooting.

Features at a Glance

Key components: Briggs & Stratton 5.5 HP engine, 21-inch steel cutting deck, 3-in-1 discharge system, single-lever height adjustment, large rear grass bag, ergonomic handle.

Assembly Instructions

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

1. Attach handle: Align lower handle with deck brackets, secure with bolts and wing nuts.
2. Install upper handle: Connect to lower handle, secure with provided hardware.
3. Attach grass bag: Hook bag frame onto rear deck brackets; ensure secure fit.
4. Install side-discharge chute: Attach to discharge opening on right side of deck.
5. Add engine oil: Fill with SAE 30 detergent oil (check dipstick for level).
6. Add gasoline: Use fresh unleaded gasoline (87 octane minimum).

WARNING! Do not add gasoline during assembly; wait until assembly is complete and mower is outdoors.

Safety Precautions

Read all instructions before operation. Always wear appropriate safety gear.

1. Clear mowing area: Remove stones, sticks, wire, and other objects.
2. Check fuel outdoors: Add gasoline in well-ventilated area, away from ignition sources.
3. Inspect mower: Ensure all parts are properly installed and secure.
4. Wear protection: Use safety glasses, sturdy shoes, and long pants.
5. Keep bystanders away: Especially children and pets.
6. Never leave running mower unattended.

CAUTION! Engine and muffler become extremely hot during and after use. Allow to cool before touching or storing.

Specifications

• Engine: Briggs & Stratton 5.5 HP, 4-cycle, OHV.
• Cutting Width: 21 inches.
• Cutting Height Range: 1.5 to 3.75 inches (6 positions).
• Deck: 21-inch steel, powder-coated.
• Discharge: 3-in-1 (mulch, bag, side-discharge).
• Grass Bag Capacity: 1.9 bushels.
• Wheels: 8-inch rear, 7-inch front.
• Starting: Recoil pull-start.
• Fuel Tank Capacity: 0.5 gallons.
• Oil Capacity: 20 oz (SAE 30).
• Weight: Approx. 60 lbs.

Controls and Operation

Handle Controls: Engine control lever (must be held to run), height adjustment lever, bag attachment handle.

Starting Procedure:

1. Check oil and fuel levels.
2. Move mower to clear, flat area outdoors.
3. Push primer bulb 3 times (cold engine).
4. Set engine control lever to START position.
5. Pull recoil starter cord firmly.
6. Once started, adjust throttle to desired speed.

Stopping: Release engine control lever; engine will stop. Wait for blade to completely stop before leaving mower.

Cutting Height Adjustment

Single-lever adjustment for all four wheels simultaneously.

1. Stop engine and wait for blade to stop.
2. Pull height adjustment lever toward wheel.
3. Move lever to desired height setting (1-6).
4. Release lever; ensure it locks into position.
5. Check that all wheels are at same height.

Tip: For first mow of season or very tall grass, use highest setting, then lower for subsequent passes.

3-in-1 Function Setup

Configure mower for mulching, bagging, or side-discharge.

1. Mulching: Install mulch plug (covers discharge opening). Grass is cut finely and returned to lawn.
2. Bagging: Remove mulch plug, attach grass bag to rear brackets. Collects clippings for disposal.
3. Side-Discharge: Remove mulch plug and bag, attach side-discharge chute. Ejects clippings to side.

WARNING! Always stop engine and ensure blade is stopped before changing discharge configuration.

Maintenance Schedule

Regular maintenance ensures optimal performance and longevity.

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

Storage Guidelines

Proper storage prevents damage and prepares mower for next season.

1. Clean mower thoroughly: Remove grass clippings from deck, wheels, and engine.
2. Drain or stabilize fuel: Run engine dry or add fuel stabilizer to full tank.
3. Change oil: If near service interval.
4. Remove spark plug: Add teaspoon of oil to cylinder, pull starter cord slowly, reinstall plug.
5. Store in dry, covered area: Protect from moisture and extreme temperatures.

Tip: Store mower with empty grass bag to prevent mildew.

Warranty Information

Murray MPH550 includes a limited 2-year warranty covering defects in materials and workmanship under normal residential use. Proof of purchase required. Warranty does not cover damage from misuse, neglect, commercial use, or normal wear. For warranty service, contact Murray Customer Support at 1-800-XXX-XXXX or visit www.murray.com. Keep this manual and purchase receipt for reference.

Troubleshooting

Service: For technical support, call 1-800-XXX-XXXX or visit www.murray.com.