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MTD
Gas Walk-Behind Mower

Model # 508 Official MTD gas lawn mower

Here are the diagrams and repair parts for Official MTD 508 gas lawn mower, as well as links to manuals and error code tables, if available.

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Not all parts are shown on the diagrams—those parts are labeled NI, for “not illustrated”.

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Owner’s manual

Model diagram and schematic

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ALL PARTS
Showing 10 of 51 parts  |
Yard Machines Lawn & Garden Equipment Hex Bolt, 3/8-24 X 1-1/2-in (replaces 910-1044) 710-1044
#25

Mower diagram

Yard machines lawn & garden equipment hex bolt, 3/8-24 x 1-1/2-in (replaces 910-1044)

Part #710-1044

BEST SELLER
This item is not returnable
$5.33 | 
16% OFF Phone Price : $6.33
In Stock
Lawn Mower Blade Adapter 748-0376C
#23

Mower diagram

Lawn mower blade adapter

Part #748-0376C

Replaced by #748-0376E

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Manufacturer substitution
This part replaces 748-0376C. Substitute parts can look different from the original.
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Get free shipping with Automatic Reorder

$23.53 | 
20% OFF Phone Price : $29.53
In Stock
Lawn Tractor Screw (replaces 01000628, 01000865, 1186307, 1186308, 791-180288, 791-683298, 910-0599) 710-0599
#43

Mower diagram

Lawn tractor screw (replaces 01000628, 01000865, 1186307, 1186308, 791-180288, 791-683298, 910-0599)

Part #710-0599

BEST SELLER
This item is not returnable
$4.91 | 
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In Stock
Knob Wing Nut 720-0284
#6

Mower diagram

Knob wing nut

Part #720-0284

Replaced by #720-04072A

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Manufacturer substitution
This part replaces 720-0284. Substitute parts can look different from the original.
BEST SELLER
$9.33 | 
10% OFF Phone Price : $10.33
In Stock
Hinge Pin 747-0710
#33

Mower diagram

Hinge pin

Part #747-0710

Replaced by #747-0710A

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Manufacturer substitution
This part replaces 747-0710. Substitute parts can look different from the original.
This item is not returnable
$4.76 | 
17% OFF Phone Price : $5.76
In Stock
Lawn Mower Lower Handle 749-04037
#10

Mower diagram

Lawn mower lower handle

Part #749-04037

$66.59 | 
8% OFF Phone Price : $72.59
In Stock
Lawn & Garden Equipment Cable Tie 725-0157
#9

Mower diagram

Lawn & garden equipment cable tie

Part #725-0157

Replaced by #726-0178

?
Manufacturer substitution
This part replaces 725-0157. Substitute parts can look different from the original.
This item is not returnable
$2.16
In Stock
Yard Machines Lawn & Garden Equipment Cupped Washer 736-0270
#20

Mower diagram

Yard machines lawn & garden equipment cupped washer

Part #736-0270

This item is not returnable
$5.10 | 
16% OFF Phone Price : $6.10
In Stock
Lawn Mower Height Adjuster Lever (replaces 687-02051) 732-1026
#32

Mower diagram

Lawn mower height adjuster lever (replaces 687-02051)

Part #732-1026

This item is not returnable
$10.14 | 
16% OFF Phone Price : $12.14
In Stock
Yard-man Lawn & Garden Equipment Hex Screw 710-1256
#49

Mower diagram

Yard-man lawn & garden equipment hex screw

Part #710-1256

This item is not returnable
$10.37
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 run rough?

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

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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 vibrate a lot?

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

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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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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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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 replace a lawn mower spark plug

How to replace a lawn mower spark plug

Take a few minutes to replace the spark plug during your lawn mower's annual tune-up or if the spark plug is burnt or cr…

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

How to replace a lawn mower blade

Check your lawn mower blade regularly and replaced it if it's bent or damaged. …

Read more
Repair difficulty
Time required
 15 minutes or less
How to replace a lawn mower flywheel key on a flathead engine

How to replace a lawn mower flywheel key on a flathead engine

When you hit a hard object with your mower, the flywheel can shear to protect more expensive components. Learn how to re…

Read more
Repair difficulty
Time required
 45 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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Introducing new technical repair content that we’re developing for the Sears Technical Institute

Introducing new technical repair content that we’re developing for the Sears Technical Institute

Learn about Sears Technical Institute and the advanced technical content being developed for aspiring appliance techs.…

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Top questions about Sears and Sears PartsDirect

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