Murray 7800485 Lawn Mower Manual

The Murray 7800485 is a 21-inch push lawn mower featuring a 190cc Briggs & Stratton engine, 3-in-1 cutting system (mulch/bag/side discharge), single-lever height adjustment, durable steel deck, easy-start system, and large rear wheels for enhanced maneuverability. This manual covers essential safety guidelines, assembly instructions, operation procedures, maintenance schedules, troubleshooting, and storage recommendations to ensure optimal performance and longevity of your mower.

1. Safety Instructions 2. Assembly Guide 3. Controls and 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 can result in serious injury or death.

Hazard	Precaution
Rotating Blade	Always disconnect spark plug before inspection, maintenance, or clearing jams.
Fuel Handling	Refuel outdoors only when engine is cool. Use approved fuel 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.
Electrical Hazards	Never operate mower in wet grass or rainy conditions.
Personal Protective Equipment	Wear sturdy footwear, long pants, and eye protection at all times.

Assembly Guide

Your mower requires minimal assembly. Follow these steps carefully.

Unpack: Remove all packaging materials and lay components on a flat surface.
Handle Attachment: Align upper handle with lower handle brackets. Insert provided bolts and tighten securely with included wrench.
Height Adjustment Lever: Ensure lever moves freely and locks into all cutting height positions.
Bagging/Mulching Kit: If included, attach rear bagger or mulch plug according to diagram in manual.
Wheel Check: Confirm all wheels are firmly attached and rotate smoothly.
Oil & Fuel: Add engine oil (SAE 30) to full mark on dipstick. Add unleaded gasoline (87 octane minimum) to fuel tank.

WARNING! Do not attempt to start the engine before completing assembly and adding oil. Running without oil will cause immediate engine damage.

Controls and Features

Familiarize yourself with the primary controls for safe and efficient operation.

Engine Control Lever: Must be held in the operating position to run the engine. Releases to stop engine and blade.
Recoil Starter Handle: Pull firmly to start the engine.
Single-Lever Height Adjustment: Adjusts cutting height from 1.5 to 4 inches. Move lever to desired setting before mowing.
Fuel Tank Cap: Located on top of engine. Twist to open for refueling.
3-in-1 Discharge System: Configure for mulching (plug installed), bagging (bag attached), or side discharge (chute attached).
Deck Wash Port: Connect garden hose to clean underside of deck after use.

Specifications

Model: Murray 7800485
Cutting Width: 21 inches
Cutting Heights: 6 positions (1.5" - 4.0")
Engine: 190cc Briggs & Stratton 675 Series, 4-cycle
Fuel Tank Capacity: 1.0 quart (0.95 L)
Oil Capacity: 20 oz (0.6 L) SAE 30
Deck Material: Powder-coated steel
Wheels: 8-inch rear, 7-inch front
Weight: 65 lbs (approx.)
Warranty: 2-year limited

Operation Instructions

Proper starting and mowing techniques ensure a clean cut and extend mower life.

Pre-Start Check: Verify oil level, fuel level, and that area is clear of debris.
Starting Cold Engine: Set throttle to "FAST" position. Prime engine (if equipped) 3 times. Pull starter cord firmly.
Starting Warm Engine: Set throttle to "FAST" and pull starter cord.
Mowing Technique: Mow at a steady walking pace. Overlap each pass slightly for even cutting.
Tall Grass: For grass over 6 inches, mow at highest setting first, then lower for second pass.
Stopping: Release engine control lever. Wait for all moving parts to stop completely.

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

Maintenance Schedule

Regular maintenance is critical for safety and performance.

Interval	Task
Before each use	Check for loose fasteners, damaged parts, oil level, and blade condition.
Every 5 hours	Check air filter. Clean or replace if dirty.
Every 25 hours	Change engine oil (more frequently in dusty conditions).
Every season	Sharpen or replace blade. Check spark plug and replace if worn.
As needed	Clean underside of deck. Lubricate wheel bearings and height adjustment points.

Blade Sharpening/Replacement: Always disconnect spark plug. Use a torque wrench to tighten blade bolt to 40-50 ft-lbs.

Storage Guidelines

Proper end-of-season storage prevents fuel system issues and corrosion.

Fuel System: Option A: Add fuel stabilizer and run engine for 5 minutes. Option B: Drain fuel tank and carburetor completely.
Engine: Change oil. Remove spark plug, add 1 tablespoon of oil into cylinder, pull starter cord slowly to coat cylinder wall, reinstall plug.
Cleaning: Thoroughly clean the mower deck and undercarriage. Allow to dry completely.
Blade: Sharpen blade and apply a light coat of oil to prevent rust.
Storage Location: Store in a clean, dry place, covered with a breathable cloth.

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

Troubleshooting

Symptom	Possible Cause	Corrective Action
Engine will not start	Empty fuel tank, old fuel, clogged air filter, spark plug disconnected.	Add fresh fuel, clean/replace air filter, ensure spark plug wire is connected.
Engine runs poorly or stalls	Dirty air filter, water in fuel, clogged fuel line.	Clean air filter, drain fuel tank and refill with fresh fuel.
Uneven cutting	Dull or bent blade, uneven tire pressure, mowing too fast.	Sharpen or replace blade, check tire pressure, slow mowing pace.
Excessive vibration	Loose blade, damaged blade, debris lodged in blade.	Stop engine immediately. Disconnect spark plug. Tighten or replace blade.
Mower leaves grass streaks	Deck clogged with grass, cutting height too low.	Clean deck, raise cutting height.
Wheels do not turn freely	Debris around axles, lack of lubrication.	Clean axles and apply light lubricant.

Warranty Information

The Murray 7800485 Lawn Mower is covered by a 2-Year Limited Warranty for residential use. This warranty covers defects in materials or workmanship. It does not cover damage from misuse, lack of maintenance, commercial use, or normal wear items like blades, belts, and tires. Proof of purchase is required for warranty service.

For Service: Contact Murray Customer Support at 1-800-XXX-XXXX or visit www.murray.com. Have your model number (7800485) and serial number ready.

Replacement Parts: Use only genuine Murray replacement parts to maintain performance and warranty coverage.