Murray 7800239 Lawn Mower Manual

The Murray 7800239 is a 21-inch, 3-in-1 push lawn mower featuring a 159cc Briggs & Stratton engine, rear bagging, side discharge, and mulching capabilities. It includes a single-lever height adjustment system (1.5-3.75 inches), durable steel deck, easy-start system, and a 2.5-bushel grass bag. 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 Height Adjustment 7. 3-in-1 Functionality 8. Safety Features 9. Maintenance & Storage 10. Warranty Information 11. Troubleshooting

Features at a Glance

Key components: 159cc Briggs & Stratton engine, 21-inch steel cutting deck, 3-in-1 system (bag/mulch/side discharge), single-lever height adjustment, 2.5-bushel rear bag, and easy-start technology.

Feature	Description
Engine	159cc Briggs & Stratton 450E Series, 4-cycle
Cutting Width	21 inches
Cutting Height	1.5 to 3.75 inches (6 positions)
Deck Material	Powder-coated steel
Drive System	Push (manual)
3-in-1 System	Rear bagging, mulching, side discharge
Grass Bag Capacity	2.5 bushels
Starting System	Recoil start with primer bulb
Wheels	8-inch rear, 7-inch front
Weight	Approx. 65 lbs

Assembly Instructions

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

Attach handle: Align lower handle with deck brackets, secure with bolts and wing nuts.
Install upper handle: Connect to lower handle, tighten knobs.
Attach grass bag: Hook bag frame onto rear deck brackets.
Install side discharge chute (if needed): Attach to side port.
Add engine oil: Use SAE 30 (approx. 20 oz) - check dipstick.
Add gasoline: Use fresh unleaded (max 87 octane), fill to indicated level.

WARNING! Wear gloves during assembly. Ensure all bolts are tight before operation.

First-Time Setup

Before first use, complete final checks and safety inspection.

Check oil level: Ensure oil is at full mark on dipstick.
Check tire pressure: Inflate to 15-20 PSI if needed.
Inspect blade: Ensure it is sharp and securely fastened.
Test controls: Verify height adjustment lever moves smoothly.
Start engine: Prime 3 times, set choke, pull starter cord firmly.

CAUTION! Never operate without oil or with loose components. Clear area of debris before mowing.

Specifications

Model: Murray 7800239
Engine: Briggs & Stratton 450E, 159cc, 4-cycle
Cutting Width: 21 inches
Cutting Height Range: 1.5" - 3.75" (6 positions)
Deck: 21-inch steel, powder-coated
Bag Capacity: 2.5 bushels
Wheels: 8" rear, 7" front
Weight: 65 lbs (approx.)
Fuel Tank: 0.5 gallon
Oil Capacity: 20 oz (SAE 30)
Warranty: 2-year limited

Controls and Operation

Main controls: Starter handle, primer bulb, throttle control, height adjustment lever, bag attachment lever.

Starting Procedure:

Check oil and fuel levels.
Prime bulb 3 times (cold engine).
Set throttle to FAST position.
Pull starter cord firmly until engine starts.
Allow engine to warm up 30 seconds.

Stopping: Move throttle to STOP position. Disconnect spark plug wire for safety during maintenance.

Cutting Height Adjustment

Single-lever system adjusts all four wheels simultaneously.

Locate adjustment lever on right side of deck.
Pull lever outward to release lock.
Move lever to desired height setting (1-6).
Release lever to lock in position.

Height Settings: 1 (1.5"), 2 (2"), 3 (2.5"), 4 (2.75"), 5 (3.25"), 6 (3.75").

Tip: Adjust height when mower is on flat surface. Higher settings for tall grass, lower for fine lawns.

3-in-1 Functionality

Configure mower for bagging, mulching, or side discharge.

Rear Bagging: Attach grass bag to rear brackets. Install mulch plug in discharge opening.
Mulching: Install mulch plug. Remove grass bag. Mulching blade recommended.
Side Discharge: Attach side discharge chute. Remove mulch plug and grass bag.

WARNING! Always stop engine and disconnect spark plug before changing configuration.

Safety Features

Safety key: Must be installed to start engine. Blade control: Handle must be engaged to keep blade spinning. Protective shield: Covers discharge area. Spark plug disconnect: Prevents accidental starting during maintenance.

Maintenance & Storage

Regular maintenance ensures longevity and safe operation.

After each use: Clean deck, check blade sharpness.
Every 25 hours: Change engine oil (SAE 30).
Every season: Replace air filter, spark plug.
Blade sharpening: Sharpen or replace when dull (disconnect spark plug first).
Storage: Drain fuel or add stabilizer. Store in dry place, cover mower.

CAUTION! Never store with fuel in tank for more than 30 days without stabilizer.

Warranty Information

Murray 7800239 includes a 2-year limited warranty covering defects in materials and workmanship. Warranty does not cover normal wear, misuse, or lack of maintenance. For warranty service, contact Murray customer service at 1-800-269-6215 or visit www.murray.com. Keep original receipt as proof of purchase.

Troubleshooting

Symptom	Possible Cause	Corrective Action
Engine won't start	No fuel, old gas, clogged air filter	Add fresh fuel, clean/replace air filter, check spark plug.
Engine runs poorly	Dirty carburetor, old oil	Clean carburetor, change oil, check fuel line.
Uneven cutting	Dull blade, uneven tire pressure	Sharpen/replace blade, inflate tires evenly.
Excessive vibration	Loose blade, bent blade	Tighten blade bolt (59-65 ft-lbs), replace if bent.
Bag not filling	Clogged deck, wet grass	Clean underside of deck, mow when grass is dry.
Wheels not turning	Debris in axle, lack of lubrication	Clean axle, apply light grease.

Service: For technical support, call 1-800-269-6215 or visit www.murray.com.