MTD
Gas Walk-Behind Mower

Model # 12AE999P099 Official MTD lawn mower

Here are the diagrams and repair parts for Official MTD 12AE999P099 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 257 parts  |

Troybilt Lawn Mower 21-in Deck Mulching Blade (replaces 01002810, 742-0741a, 942-04276, 942-0741) 942-0741A
#34

Handle/deck/chute diagram

Troybilt lawn mower 21-in deck mulching blade (replaces 01002810, 742-0741a, 942-04276, 942-0741)

Part #942-0741A

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Yard Machines Lawn & Garden Equipment Lock Nut, 5/16-18 (replaces 753-05591) 712-04063
Yard machines lawn & garden equipment lock nut, 5/16-18 (replaces 753-05591)

Part #712-04063

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Lawn Mower Blade Support (replaces 936-0524a) 736-0524B
#32

Handle/deck/chute 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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Yard Machines Lawn Mower Handle Knob (replaces 01000382, 113589, 720-04072, 720-04125) 720-04072A
#13

Handle/deck/chute diagram

Yard machines lawn mower handle knob (replaces 01000382, 113589, 720-04072, 720-04125)

Part #720-04072A

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Lawn Tractor Screw, 1/4-20 X 5/8-in (replaces 910-1652) 710-1652
Lawn tractor screw, 1/4-20 x 5/8-in (replaces 910-1652)

Part #710-1652

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Lawn & Garden Equipment Wing Nut (replaces 01000203, 912-0397) 712-0397A
Lawn & garden equipment wing nut (replaces 01000203, 912-0397)

Part #712-0397A

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Lawn & Garden Equipment Wing Nut 912-0397
#51

Drive diagram

Lawn & garden equipment wing nut

Part #912-0397

Replaced by #712-0397A

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Manufacturer substitution
This part replaces 912-0397. Substitute parts can look different from the original.
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Lawn & Garden Equipment Carriage Bolt (replaces 1186069, 583108, 706-101080, 706-10602-12, 791-182213) 710-0703
#23

Handle/deck/chute diagram

Lawn & garden equipment carriage bolt (replaces 1186069, 583108, 706-101080, 706-10602-12, 791-182213)

Part #710-0703

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Lawn & Garden Equipment Hex Cap Screw 710-0751
#14

Drive diagram

Lawn & garden equipment hex cap screw

Part #710-0751

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Lawn Mower Tie Cable 926-0240
#16

Handle/deck/chute diagram

Lawn mower tie cable

Part #926-0240

Replaced by #726-0178

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Manufacturer substitution
This part replaces 926-0240. Substitute parts can look different from the original.
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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

Learn about a new feature added to the Search Bar on Sears PartsDirect…

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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