Murray MB1842LT Lawn Mower Manual

The Murray MB1842LT is an 18.5 HP, 42-inch riding lawn mower with a Briggs & Stratton engine, hydrostatic transmission, 6-speed gear drive, electric start, 3-in-1 cutting system (mulch/bag/side discharge), adjustable cutting height (1.5-4 inches), comfortable high-back seat, 2.5-gallon fuel tank, and durable steel deck. Below are key sections for safety, features, assembly, operation, maintenance, troubleshooting, and specifications.

1. Features at a Glance 2. Assembly Instructions 3. Safety Precautions 4. Specifications 5. Controls and Operation 6. Cutting & Mowing 7. Maintenance Schedule 8. Storage Instructions 10. Regulatory Information 11. Troubleshooting

Features at a Glance

Key components: 18.5 HP Briggs & Stratton engine, 42-inch steel cutting deck, Hydrostatic transmission, Electric start with key, High-back seat, Deck lift lever, Cutting height adjustment, Fuel gauge, Headlights.

Feature	Description
Engine	18.5 HP Briggs & Stratton, single cylinder, OHV
Cutting Width	42 inches
Transmission	Hydrostatic (infinite speed control)
Cutting Options	Mulch, Bag, Side Discharge (3-in-1)
Cutting Height	Adjustable 1.5 to 4 inches (6 positions)
Fuel Tank	2.5 gallons
Seat	High-back, padded, adjustable
Start Type	Electric key start (12V battery included)
Deck Material	12-gauge steel
Wheels	Front: 13", Rear: 20"

Assembly Instructions

Unpack and inspect all parts. Assembly requires basic tools (wrenches, screwdriver).

Install steering wheel: Align and secure with provided bolt.
Attach seat: Mount using four bolts and washers.
Install battery: Connect red (+) then black (-) terminals.
Attach cutting deck: Align with mounting points and secure with pins.
Install discharge chute or bagger: Attach according to chosen configuration.
Check tire pressure: Inflate to 10 PSI (front) and 12 PSI (rear).

WARNING! Mower is heavy; use assistance during assembly. Ensure all bolts are tightened securely.

Safety Precautions

Always follow safety guidelines to prevent injury.

Read manual completely before operation.
Clear mowing area of debris, rocks, and toys.
Wear sturdy shoes, eye protection, and hearing protection.
Do not mow on slopes greater than 15 degrees.
Never allow passengers, especially children.
Disengage blades and set parking brake before dismounting.
Keep hands and feet away from moving parts.
Refuel only when engine is cool and outdoors.

DANGER! Rotating blades can cause severe injury. Always shut off engine and remove key before performing any maintenance.

Specifications

Model: Murray MB1842LT
Engine: 18.5 HP Briggs & Stratton, OHV
Cutting Deck: 42-inch, 12-gauge steel
Transmission: Hydrostatic, single pedal control
Speed Range: 0-5.5 mph forward, 0-2.5 mph reverse
Cutting Height: 1.5" to 4" (6 positions)
Fuel Capacity: 2.5 gallons (unleaded gasoline only)
Battery: 12V, 230 CCA
Weight: 480 lbs (approx.)
Warranty: 2-year limited

Controls and Operation

Familiarize yourself with all controls before starting.

Dashboard/Controls: Ignition key, Throttle/Choke, Blade engagement lever, Parking brake, Deck lift lever, Hour meter, Fuel gauge, Headlight switch.

Operation Steps:

Pre-start check: Oil level, fuel, tire pressure, clear area.
Set parking brake, ensure blades are disengaged.
Adjust throttle to halfway, turn key to start.
Release parking brake, slowly press drive pedal to move.
Engage blades only when ready to cut.
Adjust speed with pedal pressure (forward/reverse).
To stop: Release drive pedal, engage parking brake, disengage blades, turn key off.

Cutting & Mowing

For best results, follow these mowing practices.

Height Adjustment: Use deck lift lever to select cutting height (1.5-4 inches).
Cutting Patterns: Overlap each pass by 2-3 inches for even cut.
3-in-1 System: Configure for mulching (install plug), bagging (attach bagger), or side discharge (attach chute).
Slope Mowing: Mow up and down slopes, not across. Avoid steep inclines.
Wet Grass: Avoid mowing wet grass to prevent clogging and uneven cut.
Blade Sharpness: Sharp blades provide cleaner cut and reduce engine strain.

Tip: Never remove more than 1/3 of grass height in a single mowing session.

Maintenance Schedule

Regular maintenance ensures longevity and performance.

Interval	Task
Before each use	Check oil level, tire pressure, fuel, clear deck of debris
Every 8 hours	Check battery terminals, inspect blades for damage
Every 25 hours	Change engine oil (SAE 30), check air filter
Every 50 hours	Replace air filter, sharpen blades, check spark plug
Every 100 hours	Replace spark plug, change oil filter, lubricate moving parts
Seasonally	Clean underside of deck, inspect belts, check transmission fluid

Oil Type: SAE 30 (above 40°F) or 10W-30 (variable temps). Capacity: 1.5 quarts.

Storage Instructions

Proper storage prevents damage during off-season.

Run engine to warm oil, then drain and refill with fresh oil.
Add fuel stabilizer to tank, run engine for 5 minutes to circulate.
Disconnect battery negative terminal to prevent drain.
Clean entire mower, especially underside of deck.
Store in dry, covered area, preferably on level surface.
Cover with breathable tarp to protect from dust.

CAUTION! Never store with fuel in tank without stabilizer. Gasoline can degrade and damage fuel system.

Regulatory Information

This product complies with ANSI/OPEI B71.1-2012 safety standards for ride-on mowers. Engine meets EPA Phase 3 emissions requirements. Copyright © Murray LLC. For support, visit www.murray.com or contact customer service at 1-800-800-7310. Keep this manual for future reference.

Troubleshooting

Symptom	Possible Cause	Corrective Action
Engine won't start	Dead battery, empty fuel, clogged filter	Charge/replace battery; add fuel; check/replace air filter.
Poor cutting performance	Dull blades, low engine speed, clogged deck	Sharpen/replace blades; set throttle to full; clean deck.
Excessive vibration	Damaged blade, loose blade bolt, unbalanced blade	Inspect blade for damage; tighten bolt; balance or replace blade.
Mower won't move	Parking brake engaged, drive belt loose/broken	Disengage parking brake; inspect and adjust/replace drive belt.
Battery not charging	Faulty alternator, loose connections	Check alternator output; clean and tighten battery terminals.
Engine overheats	Dirty cooling fins, low oil level, clogged air filter	Clean engine fins; check oil level; replace air filter.

Service: For repairs beyond basic maintenance, contact authorized Murray service center at 1-800-800-7310.