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Troybilt
Gas Walk-Behind Mower

Model # 12A-999K063 Official Troybilt lawn mower

Here are the diagrams and repair parts for Official Troybilt 12A-999K063 lawn mower, as well as links to manuals and error code tables, if available.

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Owner’s manual

Model diagram and schematic

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ALL PARTS
Showing 10 of 176 parts  |
Blade-21" Mu 742-0741
#85

Handle/deck/blade/wheels 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.
BEST SELLER

Get free shipping with Automatic Reorder

$27.71 | 
18% OFF Phone Price : $33.71
In Stock
Knob Assembly 720-0241
Knob assembly

Part #720-0241

Replaced by #720-04072A

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Manufacturer substitution
This part replaces 720-0241. Substitute parts can look different from the original.
BEST SELLER
$9.33 | 
10% OFF Phone Price : $10.33
In Stock
Yard Machines Lawn & Garden Equipment Bell Washer (replaces 936-0242) 736-0242
#50

Bag frme - e999 diagram

Yard machines lawn & garden equipment bell washer (replaces 936-0242)

Part #736-0242

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This item is not returnable
$6.58 | 
13% OFF Phone Price : $7.58
In Stock
Wing Nut 712-0397
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.
This item is not returnable
$5.22 | 
16% OFF Phone Price : $6.22
In Stock
Lawn & Garden Equipment Carriage Bolt (replaces 1186069, 583108, 706-101080, 706-10602-12, 791-182213) 710-0703
Lawn & garden equipment carriage bolt (replaces 1186069, 583108, 706-101080, 706-10602-12, 791-182213)

Part #710-0703

This item is not returnable
$6.46 | 
13% OFF Phone Price : $7.46
In Stock
Lawn & Garden Equipment Hex Cap Screw 710-0751
Lawn & garden equipment hex cap screw

Part #710-0751

This item is not returnable
$5.12 | 
16% OFF Phone Price : $6.12
In Stock
Toro Lawn & Garden Equipment Flat Washer 736-3084
#32

Transmission assembly/bag diagram

Toro lawn & garden equipment flat washer

Part #736-3084

This item is not returnable
$6.14 | 
14% OFF Phone Price : $7.14
In Stock
Sears Lawn Mower Roller Wheel 756-0625
#43

Handle/deck/blade/wheels diagram

Sears lawn mower roller wheel

Part #756-0625

This item is not returnable
$12.00 | 
14% OFF Phone Price : $14.00
In Stock
Ryobi Lawn & Garden Equipment Flat Washer 736-0204
#66

Handle/deck/blade/wheels diagram

Ryobi lawn & garden equipment flat washer

Part #736-0204

This item is not returnable
$5.43 | 
16% OFF Phone Price : $6.43
In Stock
Cable Tie 726-0240
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
$2.16
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 vibrate a lot?

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

Read more

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 run rough?

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

Read more

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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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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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 rebuild a lawn mower carburetor

How to rebuild a lawn mower carburetor

The carburetor mixes air with fuel to drive the piston. Rebuild the carburetor if it's clogged or leaks.…

Read more
Repair difficulty
Time required
 60 minutes or less
How to replace a lawn mower recoil starter on an OHV engine

How to replace a lawn mower recoil starter on an OHV engine

Replace the recoil starter if it doesn't move when you pull the starter rope.…

Read more
Repair difficulty
Time required
 15 minutes or less
How to replace a lawn mower wheel

How to replace a lawn mower wheel

Learn how replace a damaged wheel on a walk-behind lawn mower—it's a quick, easy fix.…

Read more
Repair difficulty
Time required
 15 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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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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Types of walk-behind mower blades video

Types of walk-behind mower blades video

Learn about the different kinds of mower blades and how to maintain them.…

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