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
Front-Tine Tiller

Model # 21A-154A799 Official MTD front-tine tiller

Here are the diagrams and repair parts for Official MTD 21A-154A799 front-tine tiller, 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

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 50 parts  |
Yard Machines Lawn & Garden Equipment Lock Nut, 5/16-18 (replaces 753-05591) 712-04063
#6

Cultivator assembly diagram

Yard machines lawn & garden equipment lock nut, 5/16-18 (replaces 753-05591)

Part #712-04063

BEST SELLER
This item is not returnable
$4.40 | 
19% OFF Phone Price : $5.40
In Stock
Yard Machines Lawn & Garden Equipment Nut 712-04064
#27

Cultivator assembly 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
Back Order
Bolt, Hex Wa 4543
#26

Cultivator assembly diagram

Bolt, hex wa

Part #4543

Replaced by #710-0599

?
Manufacturer substitution
This part replaces 4543. Substitute parts can look different from the original.
BEST SELLER
This item is not returnable
$4.91 | 
17% OFF Phone Price : $5.91
In Stock
Knob-lower H 720-04052
#7

Cultivator assembly diagram

Knob-lower h

Part #720-04052

Replaced by #720-04072A

?
Manufacturer substitution
This part replaces 720-04052. Substitute parts can look different from the original.
BEST SELLER
$9.33 | 
10% OFF Phone Price : $10.33
In Stock
Lawn Mower Wheel (replaces 734-04086) 734-1988
#50

Cultivator assembly diagram

Lawn mower wheel (replaces 734-04086)

Part #734-1988

This item is not returnable
$23.27 | 
20% OFF Phone Price : $29.27
In Stock
Yard-man Lawn & Garden Equipment Carriage Bolt 710-0572
#3

Cultivator assembly diagram

Yard-man lawn & garden equipment carriage bolt

Part #710-0572

This item is not returnable
$6.57 | 
13% OFF Phone Price : $7.57
In Stock
Inner Tine Assembly 686-0177
#22

Cultivator assembly diagram

Inner tine assembly

Part #686-0177

Replaced by #753-05987

?
Manufacturer substitution
This part replaces 686-0177. Substitute parts can look different from the original.
$59.61 | 
9% OFF Phone Price : $65.61
In Stock
Outer Tine Assembly 686-0178
#23

Cultivator assembly diagram

Outer tine assembly

Part #686-0178

Replaced by #753-05987

?
Manufacturer substitution
This part replaces 686-0178. Substitute parts can look different from the original.
$59.61 | 
9% OFF Phone Price : $65.61
In Stock
Ace Lawn & Garden Equipment Push Cap 726-0299
#49

Cultivator assembly diagram

Ace lawn & garden equipment push cap

Part #726-0299

This item is not returnable
$12.39 | 
14% OFF Phone Price : $14.39
In Stock
Lawn & Garden Equipment Hex Bolt 710-0597
#25

Cultivator assembly diagram

Lawn & garden equipment hex bolt

Part #710-0597

This item is not returnable
$5.80
In Stock

Most common symptoms to help you fix your tillers

Choose a symptom to see related tiller repairs.

View all

Why do my tiller's tines turn but the wheels don't?

Main causes: clutch cable problems, faulty transmission…

Read more

Why does my tiller turn the soil poorly?

Main causes: damaged tines, broken clevis pins, worn drive belt, faulty transmission, clutch cable problems, improper de…

Read more

Why won't my tillers wheels or tines turn?

Main causes: worn or broken drive belts, bad transmission, clutch cable problems…

Read more

Why does my tiller's engine leak oil or gas?

Main causes: leaky engine head gasket, damaged sump gasket, damaged oil drain plug seal, loose or cracked fuel line, lea…

Read more

Why do my tiller's wheels turn but the tines don't?

Main causes: broken shaft clevis pins, transmission failure…

Read more

Why does my tiller's engine run roughly or misfire?

Main causes: dirty carburetor, engine needs tune up, stale gas…

Read more

Why won't my tiller's engine start?

Main causes: carburetor failure, bad gasoline, dirty spark plug, broken recoil starter…

Read more

Most common repair guides to help fix your tillers

These step-by-step repair guides will help you safely fix what’s broken on your tiller.

View all
How to replace a tiller recoil starter

How to replace a tiller recoil starter

The recoil starter spins the engine when you pull the starter rope, and the rope retracts when released. If the recoil s…

Read more
Repair difficulty
Time required
 15 minutes or less

Effective articles & videos to help repair your tillers

Use the advice and tips in these articles and videos to get the most out of your tiller.

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
Find the right carburetor assembly for a Craftsman snowblower, tiller or log splitter

Find the right carburetor assembly for a Craftsman snowblower, tiller or log splitter

This chart will help you find the right carburetor for your Craftsman snowblower, tiller or log splitter.…

Read more

Parts & More