Can’t find your part?   Contact us:
+1-309-603-4777
Sears Parts Direct
Tips to find your model number
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 # 21B-34M8793 Official MTD front tine gas tiller

Here are the diagrams and repair parts for Official MTD 21B-34M8793 front tine gas 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.

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 13 parts  |
Lawn & Garden Equipment Engine Spark Plug 951-10292
#NI07

Tiller diagram

Lawn & garden equipment engine spark plug

Part #951-10292

Replaced by #951-10292A

?
Manufacturer substitution
This part replaces 951-10292. Substitute parts can look different from the original.
BEST SELLER
This item is not returnable
$5.70 | 
15% OFF Phone Price : $6.70
In Stock
Tiller Drive Belt (replaces 754-0428) 954-0428
#NI02

Tiller diagram

Tiller drive belt (replaces 754-0428)

Part #954-0428

Get free shipping with Automatic Reorder

$39.73 | 
13% OFF Phone Price : $45.73
In Stock
Lawn & Garden Equipment Engine Fuel Tank Cap 951-12535
#NI05

Tiller diagram

Lawn & garden equipment engine fuel tank cap

Part #951-12535

This item is not returnable
$31.09 | 
16% OFF Phone Price : $37.09
In Stock
Tiller Forward Drive Control Cable 946-0918
#NI03

Tiller diagram

Tiller forward drive control cable

Part #946-0918

$36.69 | 
14% OFF Phone Price : $42.69
In Stock
Tiller Wheel 734-04547
#NI12

Tiller diagram

Tiller wheel

Part #734-04547

$49.29 | 
11% OFF Phone Price : $55.29
In Stock
Tine Bolt Assembly 642-04105
#NI09

Tiller diagram

Tine bolt assembly

Part #642-04105

Replaced by #642-04105-5083

?
Manufacturer substitution
This part replaces 642-04105. Substitute parts can look different from the original.
$65.92
In Stock
Tine Bolt Assembly 642-04104
#NI10

Tiller diagram

Tine bolt assembly

Part #642-04104

Replaced by #642-04104-5083

?
Manufacturer substitution
This part replaces 642-04104. Substitute parts can look different from the original.
$79.09 | 
7% OFF Phone Price : $85.09
In Stock
Tine Bolt Assembly 642-04106
#NI11

Tiller diagram

Tine bolt assembly

Part #642-04106

Replaced by #642-04106-5083

?
Manufacturer substitution
This part replaces 642-04106. Substitute parts can look different from the original.
$79.09 | 
7% OFF Phone Price : $85.09
In Stock
Tine Bolt Assembly 642-04103
#NI08

Tiller diagram

Tine bolt assembly

Part #642-04103

Replaced by #642-04103-5083

?
Manufacturer substitution
This part replaces 642-04103. Substitute parts can look different from the original.
$65.92
In Stock
Ace Lawn & Garden Equipment Foam Handle Grip 720-0274
#NI04

Tiller diagram

Ace lawn & garden equipment foam handle grip

Part #720-0274

This item is not returnable
$17.54 | 
10% OFF Phone Price : $19.54
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