Murray 7800257 Lawn Mower Manual

The Murray 7800257 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, durable steel deck, and easy-start system. This manual covers essential safety instructions, assembly, operation, maintenance, troubleshooting, and storage procedures to ensure optimal performance and longevity of your mower.

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

Safety Information

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

Hazard	Precaution
Rotating Blade	Always disconnect spark plug before inspection or maintenance. Keep hands and feet away.
Fuel Handling	Refuel outdoors only when engine is cool. Use approved container.
Debris Ejection	Clear mowing area of stones, sticks, and other objects. Wear safety glasses.
Slope Operation	Do not mow on slopes greater than 15 degrees. Mow across slopes, not up and down.
Children and Pets	Keep bystanders at least 50 feet away during operation.

Assembly Instructions

Unpack all parts and verify contents against packing list. 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 discharge chute, then hook bag onto frame.
Connect control cable: Route cable along handle and attach to engine throttle control lever.
Add oil and fuel: Fill engine with SAE 30 oil (check dipstick). Add fresh unleaded gasoline.

WARNING! Do not start engine until assembly is complete and all fasteners are tightened.

Controls and Features

Key components: Engine, Steel Deck, Handle with Controls, Grass Bag, Height Adjustment Lever.

Control/Feature	Description
Recoil Starter	Pull cord to start engine
Throttle Control	Single lever on handle for engine speed (START/RUN/STOP)
Blade Control Bail	Must be held against handle to engage and keep blade spinning
Height Adjustment Lever	Single lever adjusts all four wheels (1-3 inch cutting height)
3-in-1 Capability	Selector lever for Mulch, Bag, or Side Discharge
Fuel Tank	1.0 quart capacity
Oil Fill/Dipstick	For checking and adding engine oil

Specifications

Model: Murray 7800257
Cutting Width: 21 inches
Deck Material: Powder-coated steel
Engine: 190cc Briggs & Stratton 675 Series, 4-cycle
Starting System: Recoil
Cutting Height Range: 1 to 3 inches (6 positions)
Wheels: 8-inch rear, 7-inch front
Bag Capacity: 2.0 bushels
Weight: 65 lbs (approx.)

Operation Guide

Starting, mowing, and stopping procedures.

Pre-Start Check: Ensure oil and fuel levels are correct. Clear mowing area.
Starting Engine: Set throttle to START/FAST. Pull recoil starter firmly.
Engaging Blade: Hold blade control bail against handle. Blade will engage.
Mowing: Walk at a steady pace, overlapping passes slightly for even cut.
Stopping: Release blade control bail. Set throttle to STOP. Wait for blade to stop completely.
Height Adjustment: Move lever to desired setting before mowing.
Discharge Mode: Use selector lever to choose Mulch, Bag, or Side Discharge.

Tip: Mow when grass is dry for best results and to prevent clumping.

Maintenance Schedule

Regular maintenance ensures performance and extends mower life.

Task	Frequency	Procedure
Check Engine Oil	Before each use	Use dipstick; add SAE 30 if low.
Clean Underside of Deck	After each use	Scrape off grass buildup (engine off, spark plug disconnected).
Check/Sharpen Blade	Every 25 hours	Remove blade; sharpen evenly or replace if damaged.
Replace Air Filter	Every season or 25 hours	Remove foam pre-filter, clean in soapy water, re-oil lightly.
Change Engine Oil	First 5 hours, then every 50 hours	Drain warm oil, refill with 20 oz SAE 30.
Spark Plug Inspection	Every season	Clean, check gap (0.030"), replace if worn.

Storage Instructions

Proper storage prevents fuel system issues and corrosion.

End-of-Season: Run engine to use up fuel or add fuel stabilizer.
Clean: Thoroughly clean deck, wheels, and engine area.
Oil: Change engine oil (see Maintenance).
Spark Plug: Disconnect and remove spark plug. Add 1 tablespoon of oil into cylinder, pull starter cord slowly to coat, reinstall plug.
Store: Keep in a clean, dry place, covered.

CAUTION! Never store mower with fuel in tank indoors or in enclosed spaces without proper stabilization.

Troubleshooting

Symptom	Possible Cause	Corrective Action
Engine will not start	No fuel, old fuel, spark plug disconnected, throttle not set to START	Add fresh fuel, check spark plug wire, set throttle correctly.
Engine runs poorly or stalls	Dirty air filter, clogged fuel line, old gasoline	Clean/replace air filter, drain and replace fuel.
Uneven cutting	Dull blade, deck clogged, uneven tire pressure	Sharpen/replace blade, clean deck, check tires.
Excessive vibration	Loose blade, bent blade, debris stuck in blade	Stop engine immediately. Disconnect spark plug. Tighten or replace blade.
Mower does not self-propel	This is a push mower model; no self-propel feature.	Operation is manual push only.
Grass not discharging properly	Wet grass, deck clogged, incorrect cutting height	Mow when dry, clean deck, adjust cutting height.

Warranty Information

The Murray 7800257 Lawn Mower is covered by a limited warranty. Refer to the separate warranty card included in your packaging for full terms, conditions, and duration. For warranty service, contact an authorized Murray service dealer. Proof of purchase is required.

Customer Support: For parts, manuals, or dealer locations, visit www.murray.com or call 1-800-XXX-XXXX.