Murray MB12538LT Lawn Mower Manual

The Murray MB12538LT is a 12.5 HP Briggs & Stratton engine-powered, 38-inch cutting deck lawn tractor with 5-speed manual transmission, electric start, mulching capability, adjustable cutting height (1.5-4 inches), and a 2.5-gallon fuel tank. It features a comfortable high-back seat, cup holder, headlights, and a durable steel frame. Below are key sections for safety, features, assembly, operation, maintenance, and troubleshooting.

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

Features at a Glance

Key components: 12.5 HP Briggs & Stratton engine, 38-inch steel cutting deck, 5-speed manual transmission, Electric Start key, High-back seat, Headlights, Cup holder, Mulching plug, and Bagging attachment.

Feature	Description
Engine	12.5 HP Briggs & Stratton, 4-cycle, single cylinder
Cutting Width	38 inches
Transmission	5-speed manual (gear drive)
Starting System	Electric key start with backup recoil
Cutting Height	Adjustable 1.5 to 4 inches (6 positions)
Fuel Tank	2.5 gallons (unleaded gasoline)
Deck Engagement	Manual lever (PTO)
Seat	High-back, padded for comfort
Headlights	Two front lights for low-light mowing
Mulching/Bagging	Includes mulching plug and bagging kit

Assembly Instructions

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

Install steering wheel: Align and tighten bolt.
Attach seat: Mount using provided bolts and washers.
Install battery: Connect red (+) then black (-) terminals.
Attach cutting deck: Align with mounting points and secure with pins.
Install mulching plug or bagger (if using).
Check tire pressure (recommended 14 PSI).

WARNING! Ensure mower is on level ground during assembly. Keep hands clear of moving parts.

First-Time Setup

Before first use, complete these steps.

Add engine oil: Use SAE 30 (approx. 1.5 quarts). Check dipstick.
Add fuel: Use fresh unleaded gasoline (87 octane or higher).
Check battery: Ensure connections are tight.
Adjust seat position: Loosen knob, slide to comfortable position, retighten.
Adjust cutting height: Set lever to desired height (test on flat area).

CAUTION! Never add fuel while engine is hot or running. Work in well-ventilated area.

Specifications

Engine: 12.5 HP Briggs & Stratton, 4-cycle.
Cutting Deck: 38-inch stamped steel.
Transmission: 5-speed manual gear drive.
Cutting Height: 1.5 to 4 inches (6 positions).
Fuel Capacity: 2.5 gallons.
Oil Capacity: 1.5 quarts (SAE 30).
Starting: Electric key start with recoil backup.
Dimensions (LxWxH): 68 x 52 x 42 inches (approx).
Weight: 350 lbs (approx).

Controls and Operation

Operator's station: Ignition key, Throttle/Choke, Gear shift lever, Deck engagement lever, Cutting height adjuster, Brake/clutch pedal.

Starting Procedure: 1. Sit on seat. 2. Set parking brake. 3. Move gear shift to NEUTRAL. 4. Pull choke (if cold). 5. Turn key to START. 6. Release key to RUN once engine starts.

Driving: Depress brake/clutch pedal to disengage transmission. Select gear (1-5). Slowly release pedal to move. Use steering wheel to turn.

Stopping: Release deck engagement lever. Move throttle to SLOW. Turn key to OFF. Set parking brake.

Cutting & Mowing

For best results, mow when grass is dry.

Engage deck: At full throttle, slowly pull deck engagement lever.
Select speed: Use lower gears (1-2) for thick grass or slopes.
Overlap passes: Overlap by 2-3 inches for even cut.
Change direction: Alternate mowing pattern each time to prevent ruts.
Disengage deck: When finished or crossing non-grass areas.

Tip: Sharpen blades every 25 hours for clean cut. Do not cut more than 1/3 of grass height at once.

Maintenance Schedule

Regular maintenance ensures long life and performance.

Interval	Task
Before each use	Check oil level, tire pressure, fuel, and for loose parts.
Every 8 hours	Check blade condition and tightness.
Every 25 hours	Change oil (first change at 5 hours), sharpen blades, check air filter.
Every 50 hours	Replace spark plug, check battery terminals.
Every 100 hours	Replace air filter, check drive belt tension.
Season end	Full winterization (see Storage section).

Storage & Winterization

Prepare mower for off-season storage.

Add fuel stabilizer: Run engine for 5 minutes to circulate.
Change oil: Drain warm oil and refill with fresh.
Remove battery: Store in cool, dry place on wood surface; charge monthly.
Clean deck: Remove grass clippings and debris; spray with light oil to prevent rust.
Store: In dry, covered location. Cover mower with breathable cover.

CAUTION! Never store with fuel in tank over 30 days without stabilizer. Keep away from open flames.

Safety Information

Read and follow all safety rules in manual.

Wear sturdy shoes, eye protection, and long pants.
Clear mowing area of sticks, stones, and debris.
Never carry passengers.
Do not mow on slopes greater than 15 degrees.
Disengage blades before crossing driveways or gravel.
Keep hands and feet away from moving parts.
Stop engine and remove key before performing maintenance.

DANGER! Rotating blades can cause severe injury. Keep bystanders, especially children and pets, away.

Warranty & Support

Murray offers a limited 2-year residential warranty on the MB12538LT. Proof of purchase required. Warranty does not cover normal wear, misuse, or lack of maintenance. For support, visit www.murray.com or contact 1-800-800-7310. Have model number (MB12538LT) and serial number ready.

Troubleshooting

Symptom	Possible Cause	Corrective Action
Engine won't start	No fuel, bad spark plug, dead battery	Check fuel level; inspect/replace spark plug; charge/test battery.
Engine runs rough	Dirty air filter, old fuel	Clean/replace air filter; drain old gas and refill with fresh.
Uneven cut	Dull blades, uneven tire pressure	Sharpen or balance blades; adjust tires to equal PSI.
Loss of power	Clogged deck, drive belt slipping	Clean underside of deck; check belt tension and wear.
Vibration	Loose blade, damaged spindle	Tighten blade bolt; inspect spindle for damage.

Reset: For safety interlock issues, ensure you are seated, parking brake set, and blades disengaged.

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