Murray 405607x52A Lawn Mower Manual

The Murray 405607x52A is a 20-inch push lawn mower featuring a 140cc Briggs & Stratton engine, 3-in-1 mulching/bagging/side discharge capability, single-lever height adjustment (6 positions: 1.5"-3.75"), durable steel deck, easy-start system, and ergonomic handle with soft-grip. This manual covers safety, assembly, operation, maintenance, troubleshooting, and specifications.

1. Safety Instructions 2. Assembly Instructions 3. Controls and Features 4. Specifications 5. Operation 6. Maintenance Schedule 7. Storage 8. Troubleshooting 9. Warranty Information

Safety Instructions

Read all instructions before assembly and operation. Failure to follow warnings may result in serious injury.

Hazard	Precaution
Rotating Blade	Always disconnect spark plug before inspection, maintenance, or clearing jams.
Thrown Objects	Clear mowing area of sticks, stones, wire, and debris. Wear safety glasses.
Fuel Handling	Refuel outdoors only, with engine off and cool. Use approved container.
Children & Pets	Keep area clear during operation. Do not allow riders.
Slopes	Mow across slopes, not up and down. Use caution on inclines over 15°.

Assembly Instructions

Unpack all parts and verify contents against packing list.

Attach Handle: Align lower handle sections with deck brackets, secure with provided bolts and wing nuts.
Install Upper Handle: Connect upper handle to lower sections, tighten knobs.
Attach Bagging Chute (if bagging): Snap chute onto rear discharge opening.
Install Side Discharge Chute (if side discharge): Attach to right-side opening.
Add Oil: Engine is shipped without oil. Add 20 oz. of SAE 30 detergent oil (check dipstick).
Add Fuel: Use fresh unleaded gasoline (minimum 87 octane). Fill to indicated level.

WARNING! Do not start engine until assembly is complete and oil/fuel are added.

Controls and Features

Key components: Engine, Deck, Handle, Wheels, Cutting Height Lever, Bag, Mulching Plug.

Control/Feature	Description
Primer Bulb	Press 3 times for cold starts to enrich fuel mixture.
Recoil Starter	Pull cord to start engine.
Throttle Control	Set to FAST for operation, SLOW for idle.
Blade Control Handle	Must be held against handle to engage blade and keep engine running.
Cutting Height Lever	Single lever adjusts all four wheels simultaneously (6 positions).
3-in-1 Function	Mulch: Install mulch plug. Bag: Attach bag. Side Discharge: Install or remove chute.

Specifications

Model: Murray 405607x52A
Engine: Briggs & Stratton 140cc, 4-cycle, OHV
Cutting Width: 20 inches
Cutting Height: 1.5" to 3.75" (6 positions)
Deck Material: Steel
Wheels: 8" front, 8" rear
Fuel Capacity: 0.95 quarts
Oil Capacity: 20 oz. (SAE 30)
Weight: 57 lbs (approx.)
Warranty: 2-year limited

Operation

Starting, mowing, stopping, and adjusting procedures.

Starting: Set throttle to FAST. Prime (cold engine). Hold blade control handle. Pull starter cord firmly.
Mowing: Adjust height lever. Engage blade control. Push mower at steady pace. Overlap passes slightly.
Stopping: Release blade control handle. Engine will stop. Wait for blade to stop completely.
Height Adjustment: Move lever to desired position before mowing. Ensure all wheels lock at same height.
Bagging/Mulching: Install appropriate accessory. For mulching, ensure grass is dry and not too tall.

CAUTION! Never operate without grass bag, mulch plug, or side discharge chute properly installed.

Maintenance Schedule

Regular maintenance ensures long life and safe operation.

Interval	Task
Before each use	Check oil level, inspect blade for damage, clear deck of debris.
Every 25 hours	Change oil (first change after first 5 hours), check air filter, inspect spark plug.
Every season	Sharpen or replace blade, clean underside of deck, check wheel bolts.
As needed	Replace air filter, spark plug, fuel filter. Lubricate wheel axles.

Blade Sharpening: Remove blade, file cutting edge at original angle (wear gloves). Balance blade before reinstalling.

Storage

Proper storage prevents fuel system issues and corrosion.

End of Season: Run engine to use up fuel or add fuel stabilizer. Change oil. Clean deck thoroughly.
Fuel System: Either drain tank and carburetor or add stabilizer and run for 5 minutes.
Battery (if electric start): Remove and store in cool, dry place. Charge periodically.
Storage Location: Store in clean, dry place. Cover mower to protect from dust.

WARNING! Never store mower with fuel in tank indoors or near open flame.

Troubleshooting

Symptom	Possible Cause	Corrective Action
Engine won't start	No fuel, stale fuel, clogged air filter, spark plug disconnected	Check fuel level, use fresh gas, clean/replace air filter, check spark plug wire.
Engine runs poorly	Dirty air filter, old fuel, clogged carburetor	Clean air filter, drain and refill with fresh fuel, consider carburetor cleaning.
Uneven cut	Dull blade, uneven tire pressure, deck clogged	Sharpen/replace blade, check tires, clean underside of deck.
Excessive vibration	Loose blade, bent blade, debris stuck in blade	Tighten blade bolt (disconnect spark plug first), inspect/replace blade, clear debris.
Won't self-propel (if equipped)	Drive cable loose, worn drive belt	Adjust drive cable tension, inspect/replace drive belt.

Warranty Information

Murray mowers are backed by a 2-year limited warranty covering defects in materials and workmanship under normal residential use. Warranty does not cover commercial use, neglect, improper maintenance, or normal wear items (blades, belts, etc.). Proof of purchase required.

For Service: Contact authorized Murray service center. Do not attempt repairs that may void warranty.

Customer Support: 1-800-XXX-XXXX or visit www.murray.com