craftsman lawn mower manual model 91727390

The Craftsman Lawn Mower Model 91727390 is a 21-inch self-propelled gas-powered walk-behind mower featuring a 190cc Briggs & Stratton engine, 3-in-1 mulching/bagging/side-discharge capability, single-lever height adjustment (6 positions: 1.25-3.75 inches), rear-wheel drive, easy-start system, durable steel deck, and washout port for cleaning. Below are key sections for safety, features, assembly, operation, maintenance, troubleshooting, and specifications.

1. Features at a Glance 2. Assembly Instructions 3. First-Time Setup 4. Specifications 5. Controls and Operation 6. Cutting Height Adjustment 7. Maintenance Schedule 9. Safety Features 10. Storage & Winterization 11. Warranty Information 12. Troubleshooting

Features at a Glance

Key components: 190cc Briggs & Stratton engine, 21-inch steel cutting deck, rear bagger, mulching plug, side discharge chute, single-lever height adjuster, washout port, rear-wheel drive system, and primer bulb.

Feature	Description
Engine	190cc Briggs & Stratton 4-cycle OHV engine
Cutting Width	21 inches
Cutting Options	3-in-1: Mulch, Bag, Side Discharge
Drive System	Self-propelled rear-wheel drive
Height Adjustment	Single lever, 6 positions (1.25" to 3.75")
Deck Material	Durable steel with corrosion-resistant finish
Fuel Tank	1.1-quart capacity
Starter	Recoil start with primer bulb
Washout Port	For easy deck cleaning
Wheels	8-inch rear, 7-inch front

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, secure with provided hardware.
Attach grass bag: Hook bag frame onto rear deck brackets, ensure secure latch.
Install side discharge chute: Slide into slot on right side of deck, secure with pin.
Add engine oil: Use SAE 30 detergent oil (approx. 20 oz.) - check dipstick.
Add gasoline: Use fresh unleaded gasoline (87 octane minimum), fill to indicated level.

WARNING! Do not add gasoline or oil while engine is hot. Ensure all fasteners are tight before operation.

First-Time Setup

Before first use, complete final checks and break-in procedure.

Check oil level: Ensure oil is at full mark on dipstick.
Check tire pressure: Inflate to 15-20 PSI for optimal performance.
Adjust cutting height: Set lever to desired position (recommend 2.5" for first mow).
Break-in engine: Run at half throttle for first 5 minutes, then vary speed for next 25 minutes.
Test drive control: Engage drive lever; mower should move forward when lever is held.

CAUTION! Clear mowing area of debris. Keep bystanders and pets away during operation.

Specifications

Model: 91727390
Engine: Briggs & Stratton 190cc, 4-cycle OHV
Cutting Width: 21 inches
Cutting Height: 1.25 to 3.75 inches (6 positions)
Deck: 21-gauge steel, mulching capability
Drive: Self-propelled rear-wheel drive
Wheels: 8-inch rear, 7-inch front
Bag Capacity: 2.1 bushels
Fuel Capacity: 1.1 quarts
Oil Capacity: 20 oz. (SAE 30)
Weight: 68 lbs (approx.)

Controls and Operation

Handle Controls: Drive control lever, height adjustment lever, engine stop cable. Engine Controls: Throttle, choke, primer bulb, recoil starter.

Starting Procedure:

Check oil and fuel levels.
Move throttle to FAST position.
Press primer bulb 3 times (cold engine).
Pull choke to ON position (cold engine).
Pull recoil starter cord firmly until engine starts.
Move choke to OFF after engine runs smoothly.

Stopping: Release drive lever, move throttle to STOP, wait for blades to stop completely.

Cutting Height Adjustment

Single-lever adjustment for all four wheels simultaneously.

Stop engine and wait for blades to stop.
Pull height adjustment lever toward wheel.
Move lever to desired position (1-6, with 1 being lowest).
Release lever; ensure it locks into place.

Recommended Heights: 2.5-3 inches for most grasses; 1.5-2 inches for Bermuda/Zoysia.

Maintenance Schedule

Interval	Task
Before each use	Check oil level, tire pressure, blade condition
Every 5 hours	Clean underside of deck
Every 25 hours	Change engine oil, check/replace air filter
Every season	Sharpen/replace blade, check spark plug
Storage	Drain fuel or add stabilizer, clean thoroughly

Blade Sharpening: Remove spark plug wire, tip mower on side, sharpen blade at 30-degree angle.

Safety Features

Blade Brake Clutch: Stops blade within 3 seconds when handle is released. Safety Key: Must be installed for engine to start. Deadman Control: Drive lever must be held for self-propelled operation.

Storage & Winterization

For seasonal storage (over 30 days):

Drain fuel tank or add fuel stabilizer.
Run engine for 5 minutes to circulate stabilized fuel.
Change engine oil.
Clean deck thoroughly using washout port.
Remove spark plug, add 1 oz. oil to cylinder, pull starter cord slowly.
Store in dry, covered area.

CAUTION! Never store with gasoline in tank indoors. Keep away from open flames.

Warranty Information

Limited 2-year warranty from date of purchase. Covers defects in materials/workmanship. Does not cover normal wear, misuse, or improper maintenance. For warranty service, contact Craftsman Customer Support at 1-888-331-4569 or visit www.craftsman.com. Keep original receipt as proof of purchase.

Troubleshooting

Symptom	Possible Cause	Corrective Action
Engine won't start	No fuel, bad spark plug, clogged air filter	Check fuel level; clean/replace spark plug; clean air filter.
Engine runs poorly	Dirty carburetor, old gasoline	Drain old fuel; add fresh gasoline; clean carburetor.
Uneven cut	Dull blade, uneven tire pressure	Sharpen/replace blade; inflate tires evenly.
Self-propelled not working	Drive belt worn, adjustment needed	Check drive belt tension; replace if worn.
Excessive vibration	Loose blade, bent blade	Tighten blade bolt; replace bent blade.
Bag not filling	Wet grass, clogged deck	Mow when grass is dry; clean underside of deck.

Service: For technical support, call 1-888-331-4569 or visit www.craftsman.com.