Murray 7800503 Lawn Mower Manual

The Murray 7800503 is a 21-inch push lawn mower featuring a 190cc Briggs & Stratton engine, 3-in-1 mulching/bagging/side discharge capability, 6-position single-lever height adjustment, easy-fold handle for storage, and durable steel deck. This manual covers essential safety guidelines, assembly instructions, operation procedures, maintenance schedules, troubleshooting, and warranty information to ensure optimal performance and longevity of your mower.

1. Safety Instructions 2. Assembly Guide 3. Controls & Features 4. Specifications 5. Operation Instructions 6. Maintenance Schedule 7. Storage Guidelines 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 or maintenance. Keep hands and feet away.
Fuel Safety	Refuel outdoors only when engine is cool. Use approved gasoline container.
Slope Operation	Do not mow on slopes greater than 15 degrees. Mow across slopes, not up and down.
Debris & Objects	Clear mowing area of stones, toys, and other objects that could be thrown.
Children & Pets	Keep bystanders, especially children and pets, at a safe distance.
Hot Surfaces	Avoid contact with muffler and engine during and immediately after operation.

Assembly Guide

Unpack all parts and verify contents against parts list. Assembly requires basic tools (included).

Handle Assembly: Attach lower handle sections to deck using provided bolts and washers.
Upper Handle: Connect upper handle to lower sections, secure with knobs or bolts.
Control Cable: Route engine control cable along handle and connect to engine throttle lever.
Height Adjustment: Install height adjustment lever and link to deck brackets.
Bagging/Mulching Kit: Attach rear bagger or mulching plug as per intended use.

WARNING! Ensure all fasteners are tight before operation. Do not operate with loose parts.

Controls & Features

Familiarize yourself with all controls before starting the engine.

Engine Control Lever: Must be held in position to start and run engine. Releases to stop engine.
Primer Bulb: Press 3 times for cold starts to supply fuel to carburetor.
Recoil Starter: Pull handle smoothly to start engine.
Height Adjustment Lever: Single lever adjusts all four wheels to 6 cutting heights (1.5" - 4").
3-in-1 Discharge: Select mulch, bag, or side discharge by installing appropriate accessory.
Fuel Tank: 1.1-quart capacity. Located on top of engine.
Oil Fill/Dipstick: For checking and adding engine oil (SAE 30 recommended).

Specifications

Model: Murray 7800503
Cutting Width: 21 inches
Deck Material: Powder-coated steel
Engine: Briggs & Stratton 190cc, 4-cycle, OHV
Starting System: Recoil
Cutting Height: 6 positions, 1.5" to 4"
Fuel Capacity: 1.1 quarts
Oil Capacity: 20 oz (SAE 30)
Wheels: 8-inch rear, 7-inch front
Weight: 65 lbs (approx.)

Operation Instructions

Follow these steps for safe and effective mowing.

Pre-Start Check: Check oil level, fuel level, and ensure blade is secure. Clear mowing area.
Starting Engine: Set height lever. Push primer bulb 3 times. Pull recoil starter firmly.
Mowing: Engage control lever. Walk at a steady pace, overlapping passes slightly.
Stopping Engine: Release control lever. Wait for blade to stop completely.
Bagging/Mulching: For bagging, attach bag and ensure chute is clear. For mulching, install plug and ensure grass is not too wet or tall.

Tip: Mow when grass is dry for best results. Avoid mowing in extreme heat.

Maintenance Schedule

Regular maintenance ensures performance and extends mower life.

Interval	Task
Before each use	Check oil level, inspect blade for damage, clear deck of debris.
Every 25 hours	Change engine oil (more frequently in dusty conditions).
Every season	Replace air filter, spark plug. Sharpen or replace blade.
As needed	Clean underside of deck. Check wheel bolts and handle knobs for tightness.
Annually	Drain fuel for off-season storage or use fuel stabilizer.

Storage Guidelines

Proper storage prevents corrosion and starting problems.

Fuel System: Run engine dry or add fuel stabilizer to full tank and run for 5 minutes.
Cleaning: Thoroughly clean underside of deck and exterior. Allow to dry.
Oil: Change oil at end of season if due.
Blade: Remove, sharpen, and coat with light oil before reinstalling.
Storage Location: Store in a clean, dry place. Fold handle for compact storage.

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

Troubleshooting

Symptom	Possible Cause	Corrective Action
Engine won't start	No fuel, old fuel, clogged air filter, spark plug fault	Check fuel level and freshness. Clean/replace air filter. Check/replace spark plug.
Engine runs poorly	Dirty air filter, old fuel, clogged carburetor	Clean air filter. Drain old fuel. Clean carburetor.
Uneven cutting	Dull blade, uneven tire pressure, deck clogged	Sharpen or balance blade. Check tire pressure. Clean deck.
Excessive vibration	Loose blade, bent blade, debris entangled	Tighten blade bolt. Replace bent blade. Remove debris.
Mower leaves streaks	Deck clogged, cutting height too low, dull blade	Clean deck. Raise cutting height. Sharpen blade.

Warranty Information

The Murray 7800503 Lawn Mower is covered by a limited warranty. The engine is covered by a separate Briggs & Stratton warranty.

Mower Deck & Frame: Limited lifetime warranty for original purchaser against defects in materials.
Engine: Refer to Briggs & Stratton warranty card included with engine for terms (typically 2 years).
What is Not Covered: Normal wear items (blades, belts, cables), damage from misuse, neglect, accident, or commercial use.
Claim Procedure: Contact Murray customer service at 1-800-XXX-XXXX or visit www.murray.com with proof of purchase.

Note: Warranty valid only in the country of purchase.