Murray NM2255 Lawn Mower Manual

The Murray NM2255 is a 22-inch, 5.5 horsepower gas-powered push lawn mower featuring a Briggs & Stratton engine, 3-in-1 side discharge/mulching/bagging capability, single-lever height adjustment, durable steel deck, easy-start system, and large rear wheels for enhanced maneuverability. This manual covers safety, assembly, operation, maintenance, troubleshooting, and specifications to ensure proper and safe use of your mower.

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

Features at a Glance

Key components: Briggs & Stratton 5.5 HP engine, 22-inch steel cutting deck, rear bagger, mulch plug, side discharge chute, single-lever height adjustment, 8-inch rear wheels, recoil start system, and operator presence control.

Feature	Description
Engine	Briggs & Stratton 5.5 HP, 4-cycle, gas-powered
Cutting Width	22-inch steel deck
Cutting Options	Side discharge, mulching, or rear bagging (3-in-1)
Height Adjustment	Single lever adjusts all four wheels (6 positions)
Wheels	8-inch rear wheels for easy maneuvering
Start System	Recoil pull-start
Safety Features	Operator presence control (blade stop), durable steel deck
Fuel Tank	1-quart capacity
Weight	Approximately 65 lbs (assembled)
Warranty	2-year limited warranty

Assembly Instructions

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

Attach handle: Align lower handle with deck brackets, secure with provided bolts and washers.
Install upper handle: Connect to lower handle, tighten wing nuts.
Attach grass bag: Hook bag frame onto rear deck brackets, ensure secure fit.
Install side discharge chute: Slide into slot on right side of deck, secure with wing nut.
Add mulch plug: Insert into rear discharge opening when mulching.
Check wheels: Ensure all wheels are securely attached and rotate freely.
Add oil and fuel: Follow engine manual for proper type and quantity.

WARNING! Do not add fuel indoors or near ignition sources. Ensure all fasteners are tight before operation.

Safety Information

Read and understand all safety instructions before operating.

Clear mowing area: Remove stones, toys, wire, and other objects that could be thrown.
Wear appropriate clothing: Sturdy shoes, long pants, eye protection, and hearing protection.
Check fuel: Use fresh, clean unleaded gasoline. Never fill tank while engine is hot or running.
Start engine outdoors: Never start engine in enclosed area.
Operator presence: Keep hands and feet away from cutting area. Blade stops within 3 seconds when handle is released.
Slopes: Mow across slopes, not up and down. Use caution on inclines.
Children and pets: Keep them away from mowing area.

CAUTION! Engine and muffler become hot during use. Allow to cool before touching or storing.

Specifications

Model: Murray NM2255
Engine: Briggs & Stratton 5.5 HP, 4-cycle, OHV
Cutting Width: 22 inches
Cutting Height: 1.5 to 3.75 inches (6 positions)
Deck Material: Powder-coated steel
Wheels: 8-inch rear, 7-inch front
Discharge Options: Side discharge, mulching, rear bagging
Bag Capacity: 2.0 bushels
Fuel Type: Unleaded gasoline (87 octane or higher)
Oil Type: SAE 30 detergent motor oil (check engine manual)
Weight: 65 lbs (approx.)

Controls and Operation

Handle: Operator presence control lever (must be held to keep blade engaged), height adjustment lever. Engine: Throttle control, choke, primer bulb, recoil starter.

Starting Procedure:

Check oil level, add fuel.
Move throttle to FAST position.
Press primer bulb 3 times (cold engine).
Pull recoil starter firmly.
Adjust throttle to desired speed.

Stopping: Release operator presence control lever to stop blade. Move throttle to STOP position.

Cutting Height Adjustment

Single lever adjusts all four wheels simultaneously.

Stop engine and wait for blade to stop.
Pull height adjustment lever toward wheel.
Move lever to desired notch (1=lowest, 6=highest).
Release lever to lock in position.

Tip: For first mow of season or overgrown grass, set to highest setting, then lower for subsequent mows.

3-in-1 Discharge System

Configure mower for side discharge, mulching, or bagging.

Side Discharge: Install side discharge chute. Grass is ejected to right side. Ideal for tall/wet grass.
Mulching: Install mulch plug in rear opening. Grass is cut finely and returned to lawn as fertilizer. Requires dry grass and sharp blade.
Rear Bagging: Remove mulch plug, attach grass bag. Collects clippings for disposal. Empty bag when full to maintain airflow.

WARNING! Always stop engine before changing discharge configuration. Ensure attachments are securely installed.

Maintenance Schedule

Regular maintenance ensures optimal performance and longevity.

Maintenance	Frequency
Check oil level	Before each use
Check blade condition	Every 25 hours
Sharpen/replace blade	As needed (dull blade tears grass)
Clean underside of deck	After each use (when cool)
Replace air filter	Every season or 25 hours
Change oil	First 5 hours, then every 50 hours or season
Replace spark plug	Every 100 hours or season
Check wheel bolts/handle nuts	Monthly

Storage & Winterization

Proper storage prevents fuel system issues and corrosion.

Run engine to use remaining fuel, or add fuel stabilizer to full tank and run for 5 minutes.
Change oil and replace air filter if due.
Remove spark plug, add 1 tablespoon of oil to cylinder, pull starter slowly to coat, reinstall plug.
Clean entire mower, especially underside of deck.
Store in dry, covered area, preferably off concrete floor.
Cover mower to keep dust-free.

CAUTION! Never store mower with fuel in tank indoors or in poorly ventilated areas.

Warranty Information

Murray NM2255 is covered by a 2-year limited warranty for residential use. Warranty covers defects in materials or workmanship. Not covered: normal wear, misuse, neglect, commercial use, improper maintenance. Proof of purchase required. For warranty service, contact authorized Murray service center. For support, visit www.murray.com or call 1-800-XXX-XXXX.

Troubleshooting

Symptom	Possible Cause	Corrective Action
Engine won't start	No fuel, old fuel, clogged air filter, spark plug	Add fresh fuel, clean/replace air filter, check/replace spark plug.
Engine runs poorly	Dirty air filter, old fuel, clogged carburetor	Clean air filter, use fresh fuel, consider carburetor cleaner.
Uneven cutting	Dull/bent blade, uneven tire pressure, deck clogged	Sharpen/balance blade, check tire pressure, clean deck.
Excessive vibration	Loose blade, bent blade, debris in blade	Tighten blade bolt, replace bent blade, remove debris.
Bag not filling	Wet grass, full bag, dull blade, deck clogged	Mow when dry, empty bag, sharpen blade, clean deck.
Mower hard to push	Cutting height too low, wet grass, wheel issues	Raise cutting height, mow when dry, check wheel axles.

Service: For repairs beyond basic maintenance, contact authorized Murray service center at 1-800-XXX-XXXX or visit www.murray.com.