Murray 405600x50A Lawn Mower Manual

The Murray 405600x50A is a 20-inch push lawn mower featuring a Briggs & Stratton engine, 3-in-1 cutting system (mulch/bag/side discharge), single-lever height adjustment, durable steel deck, easy-start system, and rear-wheel drive. This manual covers safety, assembly, operation, maintenance, troubleshooting, and specifications to ensure proper use and longevity of your mower.

1. Features at a Glance 2. Assembly Instructions 3. First-Time Setup 4. Specifications 5. Controls and Operation 6. Cutting System Setup 7. Maintenance Schedule 8. Safety Features 9. Storage & Winterization 10. Warranty Information 11. Troubleshooting

Features at a Glance

Key components: Briggs & Stratton engine, 20-inch steel cutting deck, 3-in-1 discharge system, single-lever height adjustment, rear-wheel drive, easy-start system, and grass bag.

Feature	Description
Engine	Briggs & Stratton 140cc OHV engine
Cutting Width	20 inches
Cutting System	3-in-1 (Mulch, Bag, Side Discharge)
Height Adjustment	Single-lever, 6 positions (1.5-3.5 inches)
Drive System	Rear-wheel drive
Deck Material	Durable steel construction
Start System	Easy-start recoil
Fuel Tank	1.1 quart capacity
Wheels	8-inch rear, 7-inch front
Bag Capacity	2.0 bushels

Assembly Instructions

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

Attach handle: Secure upper and lower handle sections with provided bolts.
Install wheels: Slide wheels onto axles and secure with retaining clips.
Attach grass bag: Hook bag onto rear deck brackets.
Install discharge chute: Attach side discharge chute if using side discharge mode.
Add oil and fuel: Fill engine with SAE 30 oil (20 oz) and unleaded gasoline.

WARNING! Wear gloves during assembly. Ensure all bolts are tightened securely.

First-Time Setup

Before first use, complete these steps for optimal performance.

Check oil level: Ensure oil is at full mark on dipstick.
Add fuel: Use fresh unleaded gasoline with no more than 10% ethanol.
Adjust cutting height: Set lever to desired position (recommend 2.5" for first mow).
Test controls: Verify throttle, drive control, and blade engagement work smoothly.
Break-in period: Operate at half throttle for first 30 minutes.

CAUTION! Never add fuel while engine is hot or running.

Specifications

Model: Murray 405600x50A
Engine: Briggs & Stratton 140cc OHV
Cutting Width: 20 inches
Cutting Heights: 1.5" to 3.5" (6 positions)
Deck Material: 20-gauge steel
Drive System: Rear-wheel drive
Fuel Capacity: 1.1 quarts
Oil Capacity: 20 oz SAE 30
Weight: 65 lbs
Warranty: 2-year limited

Controls and Operation

Main controls: Throttle lever, drive control bar, blade engagement lever, height adjustment lever.

Starting Procedure: 1. Set throttle to FAST. 2. Prime engine (3-5 presses). 3. Pull recoil starter firmly.

Operation: Engage drive control to move forward. Release to stop. Engage blade lever to cut grass. Adjust height with single lever.

Stopping: Release blade engagement, set throttle to STOP, wait for blade to stop completely.

Cutting System Setup

Configure for mulch, bag, or side discharge operation.

Mulching: Install mulch plug in discharge opening.
Bagging: Attach grass bag to rear brackets.
Side Discharge: Install discharge chute on right side.

Tip: For best results, never remove more than 1/3 of grass height in single mowing.

Maintenance Schedule

Regular maintenance ensures optimal performance and longevity.

Interval	Task
Before each use	Check oil level, inspect blade, clear deck
Every 25 hours	Change oil, clean air filter, check spark plug
Every season	Sharpen/replace blade, clean underside
Storage	Drain fuel or add stabilizer

WARNING! Always disconnect spark plug before performing maintenance.

Safety Features

Blade brake system: Stops blade within 3 seconds when control released. Safety key: Prevents unauthorized operation. Discharge guard: Protects from thrown objects.

Storage & Winterization

Prepare mower for extended storage (especially winter).

Clean thoroughly: Remove grass clippings from deck and underside.
Fuel treatment: Add fuel stabilizer or drain tank completely.
Oil change: Replace oil if due before storage.
Store properly: Keep in dry, covered area away from moisture.

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

Warranty Information

2-year limited warranty covering defects in materials/workmanship. Does not cover normal wear, misuse, or improper maintenance. For warranty service, contact Murray customer service at 1-800-800-7310 or visit www.murray.com. Keep original receipt as proof of purchase.

Troubleshooting

Symptom	Possible Cause	Corrective Action
Engine won't start	No fuel, old gas, clogged filter	Add fresh fuel, check fuel line, clean/replace filter
Poor cutting performance	Dull blade, low engine speed	Sharpen/replace blade, set throttle to FAST
Uneven cut	Uneven tire pressure, bent blade	Check tire pressure, inspect/replace blade
Excessive vibration	Loose blade, damaged deck	Tighten blade bolt, inspect deck for damage
Loss of power	Dirty air filter, old oil	Clean air filter, change oil

Reset: For safety system issues, ensure all controls are fully engaged.

Service: 1-800-800-7310; www.murray.com