Troybilt
Gas Walk-Behind Mower

Model #999 Troybilt lawn mower

Here are the diagrams and repair parts for Troybilt 999 lawn mower, as well as links to manuals and error code tables, if available.


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Showing 10 of 176 parts

Lawn & Garden Equipment Bell Washer

#50

Bag frme - e999 Diagram

Lawn & garden equipment bell washer

Part #736-0242
This item is not returnable
$3.05 | 
20% OFF MSRP:$3.80

In Stock

Lawn Tractor Screw

#27

Transmission assembly/bag Diagram

Lawn tractor screw

Part #710-1652
This item is not returnable
$2.76 | 
14% OFF MSRP:$3.20

In Stock

Lawn & Garden Equipment Carriage Bolt

#34

Handle/deck/blade/wheels Diagram

Lawn & garden equipment carriage bolt

Part #710-0703
This item is not returnable
$2.73 | 
17% OFF MSRP:$3.30

In Stock

Lawn & Garden Equipment Push Cap

#94

Handle/deck/blade/wheels Diagram

Lawn & garden equipment push cap

Part #726-0214
This item is not returnable
$6.60 | 
16% OFF MSRP:$7.90

In Stock

Lawn & Garden Equipment Hex Screw

#63

Handle/deck/blade/wheels Diagram

Lawn & garden equipment hex screw

Part #710-0896
This item is not returnable
$2.83 | 
12% OFF MSRP:$3.20

In Stock

Lawn Mower Roller Wheel

#43

Handle/deck/blade/wheels Diagram

Lawn mower roller wheel

Part #756-0625
This item is not returnable
$5.71 | 
13% OFF MSRP:$6.60

In Stock

Lawn & Garden Equipment Plastic Plug

#43

Transmission assembly/bag Diagram

Lawn & garden equipment plastic plug

Part #721-0325
This item is not returnable
$2.89 | 
15% OFF MSRP:$3.40

In Stock

Lawn & Garden Equipment Hex Bolt

#87

Handle/deck/blade/wheels Diagram

Lawn & garden equipment hex bolt

Part #710-1257
This item is not returnable
$5.09

In Stock

Lawn Mower Discharge Chute

#30

Handle/deck/blade/wheels Diagram

$23.54 | 
9% OFF MSRP:$26.00

In Stock

Lawn Mower Lower Handle

#30

Bag frme - e999 Diagram

Lawn mower lower handle

Part #749-0907B
$34.30 | 
16% OFF MSRP:$41.00

In Stock

Symptoms for gas walk-behind mowers

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

Main causes: drive control cable failure, worn or broken drive belt, bad transmission, broken drive wheel
Main causes: uneven wheel height settings, damaged wheel, dull or damaged cutting blade
Main causes: dirty carburetor, bad spark plug, clogged air filter, engine choke problems, clogged gas cap vent
Main causes: damaged cutting blade, loose cutting blade, damaged flywheel key, engine needs tune up
Main causes: engine needs tune up, dirty or clogged carburetor, damaged flywheel key
Main causes: stale gas, engine needs tune up, bad spark plug, dead battery, bad recoil starter, faulty safety switch, bad ignition coil

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 replace a lawn mower flywheel key on an OHV engine

The flywheel key couples the flywheel to the engine crankshaft. Replace the flywheel key if it's broken.

Repair difficulty
Time required
 60 minutes or less
April 1, 2013
By Lyle Weischwill
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
April 1, 2013
By Lyle Weischwill
How to replace a lawn mower safety switch

The safety switch stops the engine when you release the lever on the handle. This repair guide explains how to replace it if it's not working correctly.

Repair difficulty
Time required
 30 minutes or less

Articles and videos common to all walk-behind mowers

Use the advice and tips in these articles and videos to get the most out of your walk-behind lawn mower.

October 1, 2019

Types of walk-behind mower blades video

By Sears PartsDirect staff

Learn about the different kinds of mower blades and how to maintain them.