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MTD
Gas Walk-Behind Mower

Model # 12A-528N731 Official MTD lawn mower

Here are the diagrams and repair parts for Official MTD 12A-528N731 lawn mower, as well as links to manuals and error code tables, if available.

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  • In the search box below, enter all or part of the part number or the part’s name.

Not all parts are shown on the diagrams—those parts are labeled NI, for “not illustrated”.

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For DIY troubleshooting advice and repair guides, visit our repair help section.

Owner’s manual

Model diagram and schematic

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Showing 10 of 62 parts  |
Yard Machines Lawn & Garden Equipment Hex Bolt, 3/8-24 X 1-1/2-in (replaces 910-1044) 710-1044
#35

Lawn mower diagram

Yard machines lawn & garden equipment hex bolt, 3/8-24 x 1-1/2-in (replaces 910-1044)

Part #710-1044

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$5.33 | 
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Hinge Pin 747-0710
#46

Lawn mower diagram

Hinge pin

Part #747-0710

Replaced by #747-0710A

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Manufacturer substitution
This part replaces 747-0710. Substitute parts can look different from the original.
BEST SELLER
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$4.76 | 
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Torsion Spring 732-1014
#47

Lawn mower diagram

Torsion spring

Part #732-1014

Replaced by #732-1014C

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Manufacturer substitution
This part replaces 732-1014. Substitute parts can look different from the original.
$9.11 | 
10% OFF Phone Price : $10.11
In Stock
Lawn Mower Mulching Blade 742-0742A
#33

Lawn mower diagram

Lawn mower mulching blade

Part #742-0742A

Replaced by #942-0742A

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Manufacturer substitution
This part replaces 742-0742A. Substitute parts can look different from the original.

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$23.20 | 
21% OFF Phone Price : $29.20
In Stock
Yard Machines Lawn & Garden Equipment Wing Nut (replaces 01002925, 920-0279) 720-0279
#7

Lawn mower diagram

Yard machines lawn & garden equipment wing nut (replaces 01002925, 920-0279)

Part #720-0279

This item is not returnable
$6.87 | 
13% OFF Phone Price : $7.87
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Yard Machines Lawn & Garden Equipment Guide Bolt 710-1205
#6

Lawn mower diagram

Yard machines lawn & garden equipment guide bolt

Part #710-1205

This item is not returnable
$5.01 | 
17% OFF Phone Price : $6.01
In Stock
Nut 712-0431
#20

Lawn mower diagram

Nut

Part #712-0431

Replaced by #912-0431

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Manufacturer substitution
This part replaces 712-0431. Substitute parts can look different from the original.
This item is not returnable
$7.57 | 
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Yard Machines Lawn & Garden Equipment Bolt 710-1174
#10

Lawn mower diagram

Yard machines lawn & garden equipment bolt

Part #710-1174

This item is not returnable
$10.97 | 
15% OFF Phone Price : $12.97
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Kmart Lawn Tractor Rivet 728-0199
#26

Lawn mower diagram

Kmart lawn tractor rivet

Part #728-0199

This item is not returnable
$5.75 | 
15% OFF Phone Price : $6.75
In Stock
Dowel Pin 715-0221
#42

Lawn mower diagram

Dowel pin

Part #715-0221

Replaced by #915-0221

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Manufacturer substitution
This part replaces 715-0221. Substitute parts can look different from the original.
This item is not returnable
$6.23
In Stock

Symptoms for gas walk-behind mowers

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

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Why does my lawn mower run rough?

Main causes: engine needs tune up, dirty or clogged carburetor, damaged flywheel key…

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Why does my lawn mower cut unevenly?

Main causes: uneven wheel height settings, damaged wheel, dull or damaged cutting blade…

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Why does my lawn mower vibrate a lot?

Main causes: damaged cutting blade, loose cutting blade, damaged flywheel key, engine needs tune up…

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Why won't my lawn mower start?

Main causes: stale gas, engine needs tune up, bad spark plug, dead battery, bad recoil starter, faulty safety switch, ba…

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Why does my lawn mower stall?

Main causes: dirty carburetor, bad spark plug, clogged air filter, engine choke problems, clogged gas cap vent…

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Why won't my lawn mower move?

Main causes: drive control cable failure, worn or broken drive belt, bad transmission, broken drive wheel…

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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.

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How to replace a lawn mower spark plug

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 cr…

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

How to replace a lawn mower blade

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

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

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 re…

Read more
Repair difficulty
Time required
 45 minutes or less

Effective articles & videos to help repair your 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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How to enjoy all the online benefits we offer on our Sears PartsDirect website

How to enjoy all the online benefits we offer on our Sears PartsDirect website

Learn about all the convenient features on our Sears PartsDirect website that make your parts purchases easier.…

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Introducing new technical repair content that we’re developing for the Sears Technical Institute

Introducing new technical repair content that we’re developing for the Sears Technical Institute

Learn about Sears Technical Institute and the advanced technical content being developed for aspiring appliance techs.…

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Top questions about Sears and Sears PartsDirect

Top questions about Sears and Sears PartsDirect

Get answers to frequently asked questions about Sears and Sears PartsDirect.…

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