Craftsman 21 Lawn Mower Manual

The Craftsman 21 Lawn Mower is a 21-inch walk-behind gas-powered mower featuring a Briggs & Stratton engine, 3-in-1 mulching/bagging/side-discharge capability, single-lever height adjustment, easy-start system, durable steel deck, rear-wheel drive, 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. Safety Precautions 4. Specifications 5. Controls and Operation 6. Cutting Height Adjustment 7. Maintenance Schedule 8. Storage Guidelines 9. Warranty Information 10. Parts Diagram 11. Troubleshooting

Features at a Glance

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

FeatureDescription
Cutting Width21 inches
EngineBriggs & Stratton 140cc OHV engine
Cutting OptionsMulch, Bag, Side Discharge
Height AdjustmentSingle lever, 6 positions (1.5" - 4")
Drive SystemRear-wheel drive
Grass Bag Capacity2.5 bushels
Start TypeRecoil start with easy-pull system
Deck MaterialPowder-coated steel
Wheels8-inch rear, 7-inch front
Fuel Tank Capacity0.95 gallons

Assembly Instructions

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

  1. Attach handle: Align lower handle with deck brackets, secure with bolts and wing nuts.
  2. Install grass bag: Attach bag support frame to rear discharge chute, hang bag on frame.
  3. Attach discharge chute: For side discharge, secure chute to deck opening.
  4. Install mulching plug: For mulching, insert plug into discharge opening.
  5. Add oil and fuel: Fill engine with SAE 30 oil (20 oz) and unleaded gasoline.

WARNING! Read safety section before assembly. Ensure all fasteners are tight.

Safety Precautions

Always operate mower with caution to prevent injury.

  1. Clear mowing area of stones, toys, and other objects.
  2. Wear sturdy shoes, eye protection, and long pants.
  3. Do not mow wet grass or in poor visibility.
  4. Never allow children to operate mower.
  5. Disconnect spark plug before performing maintenance.
  6. Use extreme caution when operating on slopes.

DANGER! Keep hands and feet away from rotating blade. Never remove safety devices.

Specifications

Controls and Operation

Handle Controls: Drive control lever, height adjustment lever, engine control (stop) lever.

Starting Procedure:

  1. Check oil and fuel levels.
  2. Push primer bulb 3 times (cold engine).
  3. Set engine control to RUN position.
  4. Pull recoil starter firmly.

Stopping: Release drive control, move engine control to STOP. Wait for blade to stop completely.

Drive Control: Squeeze lever against handle to engage drive; release to stop.

Cutting Height Adjustment

Single-lever adjustment for all four wheels.

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

Recommended Settings: 2.5-3 inches for most lawns; higher for uneven terrain.

Maintenance Schedule

Maintenance TaskFrequency
Check oil levelBefore each use
Clean underside of deckAfter each use
Check blade sharpness/balanceEvery 25 hours
Replace air filterEvery season or 50 hours
Change oilFirst 5 hours, then every 50 hours
Replace spark plugEvery 100 hours
Lubricate wheels and height adjusterEvery 25 hours

Note: Always disconnect spark plug before maintenance.

Storage Guidelines

Proper storage extends mower life.

  1. Drain fuel or add fuel stabilizer for long-term storage.
  2. Change oil at end of season.
  3. Clean deck thoroughly.
  4. Remove spark plug, add 1 tablespoon oil to cylinder, pull starter slowly.
  5. Store in dry, covered area.

CAUTION! Gasoline is flammable. Store in approved container away from heat sources.

Warranty Information

Craftsman mowers come with a 2-year limited warranty covering defects in materials and workmanship. Warranty does not cover normal wear, misuse, or lack of maintenance. Keep original receipt as proof of purchase. For warranty service, contact Craftsman Customer Service at 1-888-331-4569 or visit www.craftsman.com.

Parts Diagram

Refer to exploded-view diagram for part numbers and assembly. Key parts include: blade, blade adapter, deck, wheels, engine components, handle, bag, and control cables. Order genuine Craftsman replacement parts for optimal performance.

Troubleshooting

SymptomPossible CauseCorrective Action
Engine won't startNo fuel, old gas, clogged air filterCheck fuel level; use fresh gas; clean/replace air filter.
Engine runs poorlyDirty spark plug, old fuelClean or replace spark plug; drain and replace fuel.
Uneven cuttingDull blade, uneven tire pressureSharpen or replace blade; check tire pressure.
Mower vibrates excessivelyLoose blade, damaged bladeTighten blade bolt; replace bent/damaged blade.
Drive system not engagingDrive cable loose, worn drive beltAdjust drive cable; replace drive belt.
Grass not discharging properlyWet grass, clogged deckMow when grass is dry; clean underside of deck.

Service: For repairs beyond basic maintenance, contact authorized Craftsman service center.

Support: 1-888-331-4569; www.craftsman.com

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