Homelite
Gas Walk-Behind Mower

Model # HMB-21P4 Official Homelite walk-behind lawn mower

Here are the diagrams and repair parts for Official Homelite HMB-21P4 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 132 parts  |

Owner's Manual JA-99191-4

#NI

All parts diagram

Owner's manual

Part #JA-99191-4

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

Owner's Manual JA-99200-3

#NI

All parts diagram

Owner's manual

Part #JA-99200-3

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

End Rod JA-35917-9
#8

Bagger diagram

End rod

Part #JA-35917-9

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

Nut JA-44310-6
#19

Handle assembly diagram

Nut

Part #JA-44310-6

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

Pulley JA-99122-9
#3

Drive assembly diagram

Pulley

Part #JA-99122-9

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

Cover JA-35927-0
#51

Mower housing diagram

Cover

Part #JA-35927-0

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

Housing Assembly JA-99052-9
#10

Drive assembly diagram

Housing assembly

Part #JA-99052-9

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

Key JA-46310-1
#8

Drive assembly diagram

Key

Part #JA-46310-1

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

Chute JA-99191-2
#13

Mower housing diagram

Chute

Part #JA-99191-2

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

Screw JA-40888-0
#20

Mower housing diagram

Screw

Part #JA-40888-0

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

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.…