Can’t find your part?   Contact us:
+1-309-603-4777
Sears Parts Direct
Orders

  • Keep track of the models you own in your profile

    Sign in or Register to view or add models

Schedule a repair
MTD
Gas Walk-Behind Mower

Model # 12AKP38S799 Official MTD lawn mower

Here are the diagrams and repair parts for Official MTD 12AKP38S799 lawn mower, as well as links to manuals and error code tables, if available.

There are a couple of ways to find the part or diagram you need:

  • Click a diagram to see the parts shown on that diagram.
  • 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”.

We encourage you to save the model to your profile, so it’s easy to access parts and manuals for your appliance whenever you log in.

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

Owner’s manual
  View engine

Model diagram and schematic

SEARCH WITHIN THIS MODEL

?

This is the number corresponding to the part on the diagram / schematic

Search
ALL PARTS
Showing 10 of 207 parts  |
Troybilt Lawn Mower 21-in Deck Mulching Blade (replaces 01002810, 742-0741a, 942-04276, 942-0741) 942-0741A
#17

Lawn mower diagram

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

Part #942-0741A

BEST SELLER

Get free shipping with Automatic Reorder

$29.10 | 
17% OFF Phone Price : $35.10
In Stock
Lawn Mower Zone Control Cable (replaces 946-04661) 946-04661A
#69

Lawn mower diagram

Lawn mower zone control cable (replaces 946-04661)

Part #946-04661A

BEST SELLER
$18.29 | 
10% OFF Phone Price : $20.29
In Stock
Lawn Mower Rear Skirt 731-07203
#23

Lawn mower diagram

Lawn mower rear skirt

Part #731-07203

BEST SELLER
$15.19 | 
12% OFF Phone Price : $17.19
In Stock
Yard Machines Lawn & Garden Equipment Nut 712-04064
#5

Lawn mower diagram

Yard machines lawn & garden equipment nut

Part #712-04064

BEST SELLER
This item is not returnable
$4.49 | 
18% OFF Phone Price : $5.49
In Stock
Lawn Mower Lower Handle Knob (replaces 720-05066) 720-05066A
#7

Lawn mower diagram

Lawn mower lower handle knob (replaces 720-05066)

Part #720-05066A

BEST SELLER
This item is not returnable
$6.04 | 
14% OFF Phone Price : $7.04
In Stock
Yard Machines Lawn Mower Handle Knob (replaces 01000382, 113589, 720-04072, 720-04125) 720-04072A
#2

Lawn mower diagram

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

Part #720-04072A

BEST SELLER
$9.33 | 
10% OFF Phone Price : $10.33
In Stock
Lawn Tractor Screw 710-04998
#3

Lawn mower diagram

Lawn tractor screw

Part #710-04998

BEST SELLER
$8.52 | 
11% OFF Phone Price : $9.52
In Stock
Lawn & Garden Equipment Screw 710-05073
#30

Lawn mower diagram

Lawn & garden equipment screw

Part #710-05073

This item is not returnable
$6.19 | 
14% OFF Phone Price : $7.19
In Stock
Lawn Mower Square Nut 712-04222
#22

Lawn mower diagram

Lawn mower square nut

Part #712-04222

This item is not returnable
$8.40 | 
11% OFF Phone Price : $9.40
In Stock
Lawn & Garden Equipment Screw 738-04502
#37

Lawn mower diagram

Lawn & garden equipment screw

Part #738-04502

This item is not returnable
$5.23 | 
16% OFF Phone Price : $6.23
In Stock

Symptoms for gas walk-behind mowers

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

View all

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…

Read more

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…

Read more

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…

Read more

Why does my lawn mower stall?

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

Read more

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.

View all
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.

View all
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.…

Read more
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.…

Read more
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.…

Read more

Parts & More