MTD
Gas Walk-Behind Mower

Model # 12A-449R729 Official MTD lawn mower

Here are the diagrams and repair parts for Official MTD 12A-449R729 lawn mower, as well as links to manuals and error code tables, if available.

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Model diagram and schematic

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Showing 10 of 80 parts  |

Blade-21" Mu 742-0741
#62

Lawn mower diagram

Blade-21" mu

Part #742-0741

Replaced by #942-0741A

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Manufacturer substitution
This part replaces 742-0741. Substitute parts can look different from the original.
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$27.71
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Cable  37.37 746-1113
#7

Lawn mower diagram

Cable 37.37

Part #746-1113

Replaced by #946-1113A

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Manufacturer substitution
This part replaces 746-1113. Substitute parts can look different from the original.
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$20.62
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Knob Wing Nut 720-0284
#12

Lawn mower diagram

Knob wing nut

Part #720-0284

Replaced by #720-04072A

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Manufacturer substitution
This part replaces 720-0284. Substitute parts can look different from the original.
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$5.77
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Lawn Mower Blade Support (replaces 936-0524a) 736-0524B
#75

Lawn mower diagram

Lawn mower blade support (replaces 936-0524a)

Part #736-0524B

Replaced by #736-0524B-1

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Manufacturer substitution
This part replaces 736-0524B. Substitute parts can look different from the original.
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$6.11
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Wing Nut 712-0397
#33

Lawn mower diagram

Wing nut

Part #712-0397

Replaced by #712-0397A

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Manufacturer substitution
This part replaces 712-0397. Substitute parts can look different from the original.
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$5.22
16% OFF Phone Price : $6.22
In Stock
V-belt 754-0637A
#42

Lawn mower diagram

V-belt

Part #754-0637A

Replaced by #954-0637A

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Manufacturer substitution
This part replaces 754-0637A. Substitute parts can look different from the original.
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$17.69
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Lawn & Garden Equipment Hex Bolt (replaces 01000943, 910-1257) 710-1257
#74

Lawn mower diagram

Lawn & garden equipment hex bolt (replaces 01000943, 910-1257)

Part #710-1257

This item is not returnable
$9.85
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In Stock
Cable Tie 726-0240
#39

Lawn mower diagram

Cable tie

Part #726-0240

Replaced by #726-0178

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Manufacturer substitution
This part replaces 726-0240. Substitute parts can look different from the original.
This item is not returnable
In Stock
Grass Bag Frame 747-04080
#32

Lawn mower diagram

Grass bag frame

Part #747-04080

Replaced by #747-04080A

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Manufacturer substitution
This part replaces 747-04080. Substitute parts can look different from the original.
$65.07
13% OFF MSRP : $75.00
In Stock
Lawn & Garden Equipment Shoulder Screw 710-1650
#6

Lawn mower diagram

Lawn & garden equipment shoulder screw

Part #710-1650

This item is not returnable
$5.95
14% OFF Phone Price : $6.95
In Stock

Symptoms for gas walk-behind mowers

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

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

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

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…

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

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…

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. …

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…

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.

Tapping into a new feature in the Search Bar on Sears PartsDirect

Tapping into a new feature in the Search Bar on Sears PartsDirect

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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

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