Craftsman 21 Inch Lawn Mower Manual

The Craftsman 21 Inch Lawn Mower is a versatile walk-behind mower featuring a 21-inch cutting deck, Briggs & Stratton engine, 3-in-1 mulching/bagging/side-discharge capability, single-lever height adjustment (6 positions), easy-start system, durable steel deck, rear-wheel drive, and a 2.1 bushel grass bag. 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. Mulching, Bagging & Side Discharge 8. Maintenance Schedule 9. Storage & Winterization 10. Safety Information 11. Troubleshooting

Features at a Glance

Key components: 21-inch steel cutting deck, Briggs & Stratton engine, single-lever height adjuster, rear bag, mulching plug, discharge chute, and recoil starter.

Feature	Description
Cutting Width	21 inches
Engine	Briggs & Stratton 140cc OHV engine
Cutting Options	3-in-1 (Mulch, Bag, Side Discharge)
Height Adjustment	Single lever, 6 positions (1.5" - 3.75")
Drive System	Rear-wheel drive with variable speed control
Grass Bag Capacity	2.1 bushels
Deck Material	Powder-coated steel
Starter	Recoil (easy-start system)
Wheels	8-inch rear, 7-inch front
Weight	Approximately 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, secure with provided hardware.
Attach grass bag: Hook bag frame onto rear deck brackets; ensure secure fit.
Install discharge chute: Attach to side discharge opening; secure with pin or bolt.
Add engine oil: Refer to engine manual for type and capacity (typically 20 oz SAE 30).
Add gasoline: Use fresh unleaded gasoline (87 octane or higher).

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

First-Time Setup

Before first use, complete final checks and adjustments.

Check oil level: Ensure oil is at full mark on dipstick.
Inspect blade: Ensure blade is sharp and securely fastened (torque: 40-50 ft-lbs).
Adjust cutting height: Set lever to desired position (recommend 2.5" for first mow).
Test controls: Verify drive control engages smoothly; check safety key operation.
Start engine: Follow starting procedure; allow engine to warm up 30 seconds.

CAUTION! Clear mowing area of debris. Never operate without proper oil or with loose parts.

Specifications

Model: Craftsman 21-inch Walk-Behind Mower
Engine: Briggs & Stratton 140cc, 4-cycle OHV
Cutting Width: 21 inches
Cutting Height Range: 1.5" to 3.75" (6 positions)
Deck Material: Powder-coated steel
Grass Bag Capacity: 2.1 bushels
Drive System: Rear-wheel drive, variable speed
Wheels: 8" rear, 7" front
Fuel Tank Capacity: 0.5 gallons
Oil Capacity: 20 oz (SAE 30)
Weight: 65 lbs (approx.)

Controls and Operation

Main controls: Drive control lever, height adjustment lever, recoil starter, safety key, bagger handle.

Starting Procedure:

Insert safety key.
Push primer bulb 3 times (cold engine).
Set throttle to FAST position.
Pull recoil starter firmly.

Operating: Squeeze drive control to handle to engage self-propulsion; release to stop. Adjust speed with throttle. To stop engine, remove safety key.

Stopping: Release drive control, move throttle to STOP, remove key.

Cutting Height Adjustment

Single-lever adjustment for all four wheels simultaneously.

Stop engine and wait for blade 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 cut of season or overgrown grass, use higher setting (3 or 4).

Mulching, Bagging & Side Discharge

Configure for desired cutting method.

Mulching: Install mulching plug (blocks discharge chute). Grass is cut finely and returned to lawn.
Bagging: Attach grass bag; ensure discharge chute is open to bag.
Side Discharge: Remove mulching plug and bag; attach discharge chute for clippings to exit side.

WARNING! Always stop engine before changing cutting mode. Ensure attachments are secure.

Maintenance Schedule

Interval	Task
Before each use	Check oil level; inspect blade; clear deck of debris
Every 25 hours	Change engine oil; check air filter; inspect spark plug
Every season	Sharpen or replace blade; lubricate wheel axles and height adjuster
As needed	Clean underside of deck; check tire pressure; replace air filter

Blade Sharpening: Remove blade (wear gloves), sharpen at 30-degree angle, balance before reinstalling.

Storage & Winterization

Prepare mower for off-season storage.

Drain or stabilize fuel: Run engine dry or add fuel stabilizer.
Change oil: Replace with fresh oil to prevent corrosion.
Remove spark plug: Add 1 tbsp oil to cylinder, pull starter slowly to coat.
Clean thoroughly: Remove grass/debris from deck, wheels, and engine.
Store indoors: Keep in dry, covered area; cover mower.

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

Safety Information

Always: Read manual before use. Wear sturdy shoes and eye protection. Clear area of objects. Mow in daylight. Keep children and pets away.

Never: Operate without bag or chute properly attached. Mow wet grass. Remove safety devices. Put hands or feet near rotating blade. Allow children to operate.

Slope Operation: Mow across slopes, not up/down. Use extreme caution on inclines over 15 degrees.

Troubleshooting

Symptom	Possible Cause	Corrective Action
Engine won't start	No fuel; old gasoline; clogged air filter; safety key not inserted	Add fresh fuel; check air filter; insert safety key; check spark plug.
Poor cutting performance	Dull blade; low engine speed; wet grass	Sharpen/replace blade; set throttle to FAST; mow when grass is dry.
Uneven cut	Uneven tire pressure; deck not level	Inflate tires to 15 PSI; level deck (adjust front hangers).
Excessive vibration	Loose blade; bent blade; debris in deck	Tighten blade (40-50 ft-lbs); replace if bent; clean deck.
Self-propel not working	Drive cable loose; drive belt worn	Adjust drive cable tension; replace drive belt if worn.

Service: For repairs, contact authorized Craftsman service center or 1-888-331-4569.