Tecumseh
Lawn & Garden Engine

Model # TYPE 643-20C Official Tecumseh engine

Here are the diagrams and repair parts for Official Tecumseh TYPE-643-20C engine, as well as links to manuals and error code tables, if available.

There are a couple of ways to find the part or diagram you need:

  • Click a diagram to see the parts shown on that diagram.
  • In the search box below, enter all or part of the part number or the part’s name.

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

We encourage you to save the model to your profile, so it’s easy to access parts and manuals for your appliance whenever you log in.

For DIY troubleshooting advice and repair guides, visit our repair help section.

Model diagram and schematic

SEARCH WITHIN THIS MODEL

?

This is the number corresponding to the part on the diagram / schematic

Search
ALL PARTS
Showing 10 of 119 parts  |

O-ring 631028
#25

Carburetor diagram

O-ring

Part #631028

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

/carb Float 631023
#14

Carburetor diagram

/carb float

Part #631023

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

Cover 610118
#43

Basic engine diagram

Cover

Part #610118

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

Piston 310230
#5

Basic engine diagram

Piston

Part #310230

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

Spring 630766
#59

Basic engine diagram

Spring

Part #630766

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

Rewnd Startr 590420
#74

Basic engine diagram

Rewnd startr

Part #590420

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

Gasket 510274
#18

Basic engine diagram

Gasket

Part #510274

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

Pistn Rng St 310190
#6

Basic engine diagram

Pistn rng st

Part #310190

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

Bowl Gasket 631334
#21

Carburetor diagram

Bowl gasket

Part #631334

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

Pump Element 630953
#6

Carburetor diagram

Pump element

Part #630953

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

Symptoms for gas ranges

Main causes: burner igniter switch failure, bad spark module, dirty or damaged spark electrode, wiring failure…

Main causes: gas supply problem, faulty pressure regulator, clogs in burner or orifice, control system failure, faulty t…

Repair guides for gas ranges

How to replace oven door hinges on a gas range

How to replace oven door hinges on a gas range

See how to replace the oven door hinges on a gas range yourself, in just 30 minutes.…

Repair difficulty
Time required
 15 minutes or less
How to replace a range spark igniter switch

How to replace a range spark igniter switch

Follow these steps to replace the spark igniter switch—sometimes called a burner switch or spark switch—on a gas or dual…

Repair difficulty
Time required
 60 minutes or less
How to replace a range spark igniter electrode

How to replace a range spark igniter electrode

Learn how to replace the spark igniter electrode for the surface burners on a gas range or dual-fuel range.…

Repair difficulty
Time required
 45 minutes or less

Effective articles & videos to help repair your lawn & garden engines

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.…

What are the main components of a lawn mower?

What are the main components of a lawn mower?

Learn about the main parts of a lawn mower and when to replace parts.…