Murray 405000x8B Lawn Mower Manual

The Murray 405000x8B is a 21-inch push lawn mower featuring a 190cc Briggs & Stratton engine, 3-in-1 mulching/bagging/side-discharge capability, single-lever height adjustment (6 positions from 1.5" to 4"), durable steel deck, easy-start system, and rear-bagging collection system. Below are key sections for safety, features, assembly, operation, maintenance, troubleshooting, and specifications.

1. Features at a Glance 2. Assembly Instructions 3. Safety Information 4. Specifications 5. Controls and Operation 6. Cutting Height Adjustment 7. 3-in-1 Function Setup 8. Maintenance Schedule 9. Storage Instructions 10. Warranty Information 11. Troubleshooting

Features at a Glance

Key components: 190cc Briggs & Stratton engine, 21-inch steel cutting deck, rear grass bag, height adjustment lever, mulching plug, discharge chute, and recoil starter.

Feature	Description
Engine	190cc Briggs & Stratton 4-cycle, OHV
Cutting Width	21 inches
Cutting Height	6 positions (1.5" to 4")
Cutting Options	Mulching, Bagging, Side Discharge
Deck Material	Durable steel construction
Starter System	Recoil (pull-start)
Wheels	8-inch rear, 7-inch front
Bag Capacity	2.0 bushels (rear bag)
Weight	Approx. 65 lbs
Fuel Tank	0.95 gallons (unleaded gasoline)

Assembly Instructions

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

Attach handle: Align lower handle with deck brackets, secure with provided bolts and wing nuts.
Install grass bag: Attach bag support frame to rear deck brackets, hook bag onto frame.
Attach discharge chute: Slide chute into side discharge opening, secure with provided pin.
Install mulching plug (if using): Insert plug into discharge opening when mulching.
Add engine oil: Fill with SAE 30 detergent oil (approx. 20 oz) as per engine manual.
Add fuel: Use fresh unleaded gasoline (87 octane or higher).

WARNING! Do not add fuel or oil while engine is hot. Ensure all fasteners are tight before operation.

Safety Information

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

Clear mowing area of stones, toys, and other objects that could be thrown.
Do not mow when children or pets are present.
Always push mower forward; never pull backward or mow in reverse.
Stop engine and wait for all moving parts to stop before unclogging, adjusting, or crossing gravel drives.
Use extreme caution on slopes; mow across the face of slopes, not up and down.
Do not touch engine while running or shortly after stopping; it is very hot.

DANGER! Keep hands and feet away from rotating blades. Disconnect spark plug wire before performing any maintenance.

Specifications

Model: Murray 405000x8B
Engine: Briggs & Stratton 190cc, 4-cycle, OHV
Cutting Width: 21 inches
Cutting Height Range: 1.5" - 4" (6 positions)
Deck: 21-inch steel, 3-in-1 capability
Wheels: 8-inch rear, 7-inch front
Bag Capacity: 2.0 bushels
Fuel Capacity: 0.95 gallons
Oil Type: SAE 30 detergent (summer), check engine manual
Weight: Approximately 65 lbs

Controls and Operation

Key controls: Engine control lever (combines throttle and stop), recoil starter, height adjustment lever, and bag handle.

Starting Procedure:

Check oil and fuel levels.
Move engine control lever to FAST (rabbit) position.
Prime engine (if equipped) by pressing primer bulb 3 times.
Pull recoil starter handle briskly until engine starts.
Allow engine to warm up for 30 seconds before mowing.

Stopping: Move engine control lever to STOP position. Always disconnect spark plug wire for safety during maintenance.

Cutting Height Adjustment

Single-lever adjustment for all four wheels.

Stop engine and wait for blades to stop.
Pull height adjustment lever toward wheel.
Move lever to desired height setting (1-6, with 1 being lowest).
Release lever to lock into position.
Check that all wheels are at same height.

Tip: For first mow of season, set to highest setting. Never remove more than 1/3 of grass blade length at one time.

3-in-1 Function Setup

Configure for mulching, bagging, or side discharge.

Mulching: Install mulching plug in discharge opening. Grass is cut finely and returned to lawn as fertilizer.
Bagging: Remove mulching plug, install grass bag on rear bracket. Collects clippings for disposal.
Side Discharge: Remove mulching plug and bag, install discharge chute. Clippings are expelled to side.

WARNING! Always stop engine before changing cutting mode. Ensure all attachments are securely installed.

Maintenance Schedule

Regular maintenance ensures optimal performance and longevity.

Maintenance	Frequency
Check engine oil level	Before each use
Clean underside of deck	After each use
Check blade sharpness/balance	Every 25 hours
Replace air filter	Every season or 25 hours
Change engine oil	First 5 hours, then every 50 hours
Replace spark plug	Every season or 100 hours
Lubricate wheels and height adjuster	Every season
Check/replace drive belt (if equipped)	Every 2 seasons

Storage Instructions

Proper storage prevents fuel system issues and corrosion.

Run engine to burn remaining fuel in carburetor, or add fuel stabilizer to tank.
Change engine oil at end of season.
Clean entire mower, especially underside of deck.
Remove spark plug, add 1 tablespoon of oil to cylinder, pull starter slowly to distribute, reinstall plug.
Store in clean, dry place, protected from weather.
Cover mower to prevent dust accumulation.

CAUTION! Never store mower with fuel in tank in enclosed area. Gasoline vapors can ignite.

Warranty Information

Murray mowers are backed by a limited warranty. The 405000x8B includes a 2-year limited warranty on the mower and a 2-year limited warranty on the Briggs & Stratton engine. Warranty covers defects in materials and workmanship under normal residential use. Proof of purchase required. For warranty service, contact an authorized Murray service center. For support, visit www.murray.com or contact 1-800-800-7310.

Troubleshooting

Symptom	Possible Cause	Corrective Action
Engine won't start	No fuel, old gasoline, clogged air filter, spark plug issue	Add fresh fuel, clean/replace air filter, check/replace spark plug.
Engine runs poorly	Dirty air filter, old fuel, carburetor issues	Clean air filter, use fresh gasoline, consider carburetor cleaning.
Uneven cutting	Dull blade, uneven tire pressure, deck clogged	Sharpen/balance blade, check tire pressure, clean deck.
Excessive vibration	Loose blade, bent blade, debris in blade area	Tighten blade bolt, replace bent blade, clean under deck.
Grass not discharging properly	Wet grass, deck clogged, dull blade	Wait for grass to dry, clean deck, sharpen blade.
Wheels not turning freely	Debris in axles, need lubrication	Clean axles, lubricate with light oil.

Service: For technical support, contact 1-800-800-7310 or visit www.murray.com. Always reference model number 405000x8B.