Murray 7800336 Lawn Mower Manual

The Murray 7800336 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 rear-wheel drive. Below are key sections for safety, features, assembly, operation, maintenance, and troubleshooting.

1. Features at a Glance 2. Assembly Instructions 3. Safety Precautions 4. Specifications 5. Controls and Operation 6. Cutting Height Adjustment 7. 3-in-1 Discharge System 8. Maintenance Schedule 9. Storage Guidelines 10. Warranty Information 11. Troubleshooting

Features at a Glance

Key components: 190cc Briggs & Stratton engine, 21-inch steel cutting deck, 3-in-1 discharge system, single-lever height adjustment, rear-wheel drive, easy-start system.

Feature	Description
Engine	190cc Briggs & Stratton 4-cycle engine
Cutting Width	21-inch steel deck
Cutting System	3-in-1 (mulch, bag, side discharge)
Height Adjustment	Single-lever, 6 positions (1.5-3.75 inches)
Drive System	Rear-wheel drive
Start System	Easy-start recoil
Fuel Tank	1.0-quart capacity
Wheels	8-inch rear, 7-inch front
Weight	Approximately 65 lbs
Warranty	2-year limited

Assembly Instructions

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

Attach handle: Secure upper and lower handle sections with provided bolts.
Install wheels: Slide wheels onto axles and secure with retainer clips.
Attach discharge chute: Secure to deck opening with wing nut.
Install grass bag: Attach bag adapter and hook bag onto rear deck.
Add oil and fuel: Fill engine with SAE 30 oil (20 oz) and unleaded gasoline.

WARNING! Do not add fuel indoors or near open flames. Ensure all bolts are tightened securely.

Safety Precautions

Always follow safety guidelines to prevent injury.

Read manual completely before operation.
Clear mowing area of debris, rocks, and toys.
Wear sturdy shoes, eye protection, and long pants.
Never operate without discharge chute or bag properly installed.
Stop engine and wait for blades to stop before crossing gravel or roads.
Do not mow wet grass or in poor lighting.
Keep children and pets away from mowing area.

DANGER! Never reach under deck while engine is running. Disconnect spark plug before performing maintenance.

Specifications

Model: Murray 7800336
Engine: 190cc Briggs & Stratton 4-cycle
Cutting Width: 21 inches
Cutting Heights: 6 positions, 1.5-3.75 inches
Deck Material: Powder-coated steel
Discharge Options: Mulch, bag, side discharge
Fuel Type: Unleaded gasoline (87 octane minimum)
Oil Type: SAE 30 (20 oz capacity)
Warranty: 2-year limited warranty

Controls and Operation

Handle controls: Drive control lever, height adjustment lever, engine controls.

Starting Engine:

Check oil and fuel levels.
Push primer bulb 3 times (cold engine).
Set throttle to FAST position.
Pull recoil starter firmly.

Stopping Engine: Move throttle to STOP position.

Engaging Drive: Squeeze drive control lever against handle to move forward.

Cutting Height Adjustment

Single-lever adjustment for all four wheels.

Stop engine and wait for blades to stop.
Pull height adjustment lever outward.
Move lever to desired position (1-6).
Release lever to lock in position.

Height Settings: 1 (1.5"), 2 (2.0"), 3 (2.5"), 4 (2.75"), 5 (3.25"), 6 (3.75")

Tip: For first mow of season, set to highest position. Never remove more than 1/3 of grass blade length.

3-in-1 Discharge System

Configure for mulching, bagging, or side discharge.

Mulching: Install mulch plug in discharge opening.
Bagging: Remove mulch plug, attach bag adapter and grass bag.
Side Discharge: Remove mulch plug and bag, ensure discharge chute is installed.

WARNING! Always operate with proper configuration installed. Never operate without discharge chute or mulch plug when not bagging.

Maintenance Schedule

Regular maintenance ensures optimal performance and longevity.

Maintenance	Frequency
Check oil level	Before each use
Check air filter	Every 25 hours
Clean under deck	After each use
Sharpen blade	Every 25 hours or as needed
Change oil	First 5 hours, then every 50 hours
Replace spark plug	Every 100 hours
Check wheel bolts	Monthly

CAUTION! Always disconnect spark plug before performing maintenance.

Storage Guidelines

Proper storage prevents fuel system issues and corrosion.

Drain fuel tank or add fuel stabilizer.
Run engine until it stops to clear carburetor.
Change oil at end of season.
Clean entire mower, especially under deck.
Store in dry, covered area.
Remove spark plug and add 1 tablespoon of oil to cylinder.
Pull starter slowly to distribute oil.

Tip: Consider professional servicing before storage if used extensively.

Warranty Information

Murray 7800336 includes 2-year limited warranty covering defects in materials and workmanship. Warranty does not cover normal wear, improper maintenance, or commercial use. Proof of purchase required. For warranty service, contact authorized Murray service center. Keep this manual and receipt for warranty claims.

Troubleshooting

Symptom	Possible Cause	Corrective Action
Engine won't start	No fuel, stale fuel, clogged filter	Check fuel level; use fresh gasoline; clean/replace air filter.
Engine runs poorly	Dirty air filter, old fuel	Clean air filter; drain and replace fuel.
Uneven cutting	Dull blade, uneven tire pressure	Sharpen or replace blade; check tire pressure.
Vibration	Loose blade, bent blade	Tighten blade bolt; replace bent blade.
Loss of power	Clogged deck, dirty filter	Clean under deck; replace air filter.
Wheels not turning	Drive cable adjustment	Adjust drive cable tension.
Grass not discharging	Wet grass, clogged chute	Mow when grass is dry; clear discharge chute.

Service: For repairs beyond basic maintenance, contact authorized Murray service center. Keep model number (7800336) ready when calling.