Cub Cadet
Gas Walk-Behind Mower

Model #SC621 Official Cub Cadet gas lawn mower

Here are the diagrams and repair parts for Cub Cadet SC621 gas lawn mower, as well as links to manuals and error code tables, if available.

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Owner’s manual

Showing 10 of 158 parts

Free Shipping Lawn Mower 21-in Deck Mulching Blade (replaces 01002810, 742-0741A, 942-04276, 942-0741)#67

Deck/chute Diagram

Blade-21" mu

Part #742-0741
Replaced by #942-0741A
?
Manufacturer substitution
This part replaces 742-0741. Substitute parts can look different from the original.
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$20.68 | 
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MSRP: $31.00
Lawn Tractor Ball Bearing (replaces 01000340, 1185064, 741-0600, 941-0124, 95406)#7

Transmission assembly Diagram

Ball bearing

Part #741-0600
Replaced by #941-0600
?
Manufacturer substitution
This part replaces 741-0600. Substitute parts can look different from the original.
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$24.79 | 
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Phone Price: $29.79
Lawn & Garden Equipment Wing Nut (replaces 01002925, 920-0279)#6

Handle/bag/cover Diagram

Lawn & garden equipment wing nut (replaces 01002925, 920-0279)

Part #720-0279
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Lawn Mower Roller Wheel#14

Multi-speed pulley assembly Diagram

Lawn mower roller wheel

Part #756-0625
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Lawn Mower Ground Drive Belt (replaces 754-0460)#66

Deck/chute Diagram

V-belt

Part #754-0460
Replaced by #954-0460
?
Manufacturer substitution
This part replaces 754-0460. Substitute parts can look different from the original.
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Lawn & Garden Equipment Hex Cap Screw#16

Deck/chute Diagram

Lawn & garden equipment hex cap screw

Part #710-0751
This item is not returnable
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Lawn Mower Height Adjuster Lever (replaces 732-0803)#23

Deck/chute Diagram

Lawn mower height adjuster lever (replaces 732-0803)

Part #732-0803A
This item is not returnable
In Stock
$12.94
Lawn Mower Wheel, Rear (replaces 734-2010A)#51

Deck/chute Diagram

Wheel-comp 9

Part #734-2010
Replaced by #734-2010B
?
Manufacturer substitution
This part replaces 734-2010. Substitute parts can look different from the original.
In Stock
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Phone Price: $64.69
Lawn & Garden Equipment Cotter Pin

See All Related Diagrams

Cotter pin

Part #714-0104
Replaced by #914-0104
?
Manufacturer substitution
This part replaces 714-0104. Substitute parts can look different from the original.
This item is not returnable
In Stock
$3.89 | 
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Phone Price: $4.50
Lawn & Garden Equipment Hex Bolt (replaces 01000943, 910-1257)#70

Deck/chute Diagram

In Stock
$9.59 | 
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Phone Price: $10.59

Symptoms for gas walk-behind mowers

Choose a symptom to see related walk-behind mower repairs.

Main causes: uneven wheel height settings, damaged wheel, dull or damaged cutting blade
Main causes: damaged cutting blade, loose cutting blade, damaged flywheel key, engine needs tune up
Main causes: engine needs tune up, dirty or clogged carburetor, damaged flywheel key
Main causes: dirty carburetor, bad spark plug, clogged air filter, engine choke problems, clogged gas cap vent
Main causes: drive control cable failure, worn or broken drive belt, bad transmission, broken drive wheel
Main causes: stale gas, engine needs tune up, bad spark plug, dead battery, bad recoil starter, faulty safety switch, bad ignition coil

Repair guides for gas walk-behind mowers

These step-by-step repair guides will help you safely fix what’s broken on your walk-behind lawn mower.

How to replace a lawn mower spark plug

Take a few minutes to replace the spark plug during your lawn mower's annual tune-up or if the spark plug is burnt or cracked.

Repair difficulty
Time required
 15 minutes or less
How to replace a lawn mower blade

Check your lawn mower blade regularly and replaced it if it's bent or damaged.

Repair difficulty
Time required
 15 minutes or less
How to replace a lawn mower flywheel key on a flathead engine

When you hit a hard object with your mower, the flywheel can shear to protect more expensive components. Learn how to replace this tiny but essential part.

Repair difficulty
Time required
 45 minutes or less

Articles and videos common to all walk-behind mowers

Use the advice and tips in these articles and videos to get the most out of your walk-behind lawn mower.

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