Lawn-Boy
Gas Walk-Behind Mower

Model # L21ZSNC Official Lawn-Boy walk-behind lawn mower

Here are the diagrams and repair parts for Official Lawn-Boy L21ZSNC walk-behind lawn mower, as well as links to manuals and error code tables, if available.

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Model diagram and schematic

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ALL PARTS
Showing 10 of 218 parts  |

Nut 608311
Nut

Part #608311

The manufacturer no longer makes this part, and there's no substitute part

Choke Kit 683781

#NI

All parts diagram

Choke kit

Part #683781

Replaced by #683781

?
Manufacturer substitution
This part replaces 683781. Substitute parts can look different from the original.
In Stock
Washer 146304
#48

Drive group diagram

Washer

Part #146304

Replaced by #146304

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Manufacturer substitution
This part replaces 146304. Substitute parts can look different from the original.
This item is not returnable
In Stock
Retainer 610165
#3

Carburetor group diagram

Retainer

Part #610165

Replaced by #610165

?
Manufacturer substitution
This part replaces 610165. Substitute parts can look different from the original.
In Stock
Thrust Washer 608030
#30

Drive group diagram

Thrust washer

Part #608030

Replaced by #608030

?
Manufacturer substitution
This part replaces 608030. Substitute parts can look different from the original.
This item is not returnable
In Stock
Spring 613879
#13

Drive group diagram

Spring

Part #613879

Replaced by #613879

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Manufacturer substitution
This part replaces 613879. Substitute parts can look different from the original.
In Stock
Gasket 611827
#42

Drive group diagram

Gasket

Part #611827

Replaced by #611827

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Manufacturer substitution
This part replaces 611827. Substitute parts can look different from the original.
In Stock
Belt, 21-in 683682
#22

Housing and shroud group diagram

Belt, 21-in

Part #683682

Replaced by #612543-03

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Manufacturer substitution
This part replaces 683682. Substitute parts can look different from the original.

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In Stock
Retainer 611213
#48

Engine group diagram

Retainer

Part #611213

Replaced by #611213

?
Manufacturer substitution
This part replaces 611213. Substitute parts can look different from the original.
This item is not returnable
In Stock
Idler Pulley 607978
#5

Drive group diagram

Idler pulley

Part #607978

Replaced by #607978

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Manufacturer substitution
This part replaces 607978. Substitute parts can look different from the original.
In Stock

Symptoms for gas walk-behind mowers

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

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

Main causes: uneven wheel height settings, damaged wheel, dull or damaged cutting blade…

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

Main causes: drive control cable failure, worn or broken drive belt, bad transmission, broken drive wheel…

Main causes: stale gas, engine needs tune up, bad spark plug, dead battery, bad recoil starter, faulty safety switch, ba…

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

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.

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.…

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.…

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.…

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.

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.…

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.…

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.…