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MTD
Rear-Tine Tiller

Model # 21A-450 Official MTD rear tine gas tiller

Here are the diagrams and repair parts for Official MTD 21A-450 rear tine gas tiller, 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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Showing 10 of 161 parts  |
Lawn Tractor Screw (replaces 01000628, 01000865, 1186307, 1186308, 791-180288, 791-683298, 910-0599) 710-0599
Lawn tractor screw (replaces 01000628, 01000865, 1186307, 1186308, 791-180288, 791-683298, 910-0599)

Part #710-0599

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This item is not returnable
$4.91
| 
17% OFF Phone Price : $5.91
In Stock
Yard Machines Lawn & Garden Equipment Bell Washer (replaces 936-0242) 736-0242
Yard machines lawn & garden equipment bell washer (replaces 936-0242)

Part #736-0242

This item is not returnable
$6.58
| 
13% OFF Phone Price : $7.58
In Stock
Lock Washer 736-0119
#12

Outer and inner engine pulley/wheels diagram

Lock washer

Part #736-0119

Replaced by #936-0119

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Manufacturer substitution
This part replaces 736-0119. Substitute parts can look different from the original.
This item is not returnable
$6.05
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14% OFF Phone Price : $7.05
In Stock
Ryobi Lawn Tractor Bolt (replaces 01000369, 1509-091, 1509-117, 153015, 706-10123-20, 706-501277-1, 710-0342, 910-3005) 710-3005
#4

Handle/tine adapter/shield diagram

Ryobi lawn tractor bolt (replaces 01000369, 1509-091, 1509-117, 153015, 706-10123-20, 706-501277-1, 710-0342, 910-3005)

Part #710-3005

This item is not returnable
$5.11
| 
16% OFF Phone Price : $6.11
In Stock
Ryobi Lawn & Garden Equipment Hex Nut (replaces 912-3010) 712-3010
Ryobi lawn & garden equipment hex nut (replaces 912-3010)

Part #712-3010

$7.71
In Stock
Lawn Tractor Hex Bolt 710-3008
Lawn tractor hex bolt

Part #710-3008

This item is not returnable
$4.62
| 
18% OFF Phone Price : $5.62
In Stock
Ryobi Lawn & Garden Equipment Flat Washer 736-0204
#63

Handle/tine adapter/shield 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
Hex Nut 712-0267
#9

Outer and inner engine pulley/wheels diagram

Hex nut

Part #712-0267

Replaced by #712-3010

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Manufacturer substitution
This part replaces 712-0267. Substitute parts can look different from the original.
$7.71
In Stock
Ace Lawn & Garden Equipment Flange Lock Nut 712-3004A
Ace lawn & garden equipment flange lock nut

Part #712-3004A

This item is not returnable
$4.92
| 
17% OFF Phone Price : $5.92
In Stock
Ryobi Lawn & Garden Equipment Flat Washer 736-3088
#37

Gear case assembly diagram

Ryobi lawn & garden equipment flat washer

Part #736-3088

This item is not returnable
$6.17
In Stock

Most common symptoms to help you fix your tillers

Choose a symptom to see related tiller repairs.

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

Main causes: clutch cable problems, faulty transmission...

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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...

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Why won't my tillers wheels or tines turn?

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

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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...

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

Main causes: broken shaft clevis pins, transmission failure...

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

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

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Why won't my tiller's engine start?

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

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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.

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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...

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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.

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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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A guide to garden tillers

A guide to garden tillers

Rear tine tiller or front tine tiller, what to know to help in choosing the correct one for your needs....

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Tiller common questions

Tiller common questions

These frequently asked questions might help you figure out what's wrong with your garden tiller....

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