Get free shipping on your order, with any water filter subscription. Find my filter

Open Hamburger Menu
Sears Parts Direct
Tips to find your model number
Craftsman 143988503 engine

Craftsman 143988503 engine Parts

Here are the diagrams and repair parts for Craftsman 143988503 engine, as well as links to manuals and error code tables, if available.

By Schematic
By Part
SELECT DIAGRAM
?

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

Browse Parts for 143988503 Engine

  • Lawn & Garden Equipment Engine Screw for Craftsman 143988503 - Part 651033A

    Craftsman 4-cycle engine diagram

    Screw

    Part #651033

    Replaced by #651033A

    Info Icon
    Manufacturer substitution
    This part replaces 651033. Substitute parts can look different from the original.
    This item is not returnable
    In Stock
    $2.16
    Minus Item
    Qty
    Plus Item
  • Craftsman Baffle for Craftsman 143988503 - Part 37853

    Craftsman 4-cycle engine diagram

    Baffle

    Part #36460

    Replaced by #37853

    Info Icon
    Manufacturer substitution
    This part replaces 36460. Substitute parts can look different from the original.
    In Stock
    $12.63
    Minus Item
    Qty
    Plus Item
  • Craftsman Lawn & Garden Equipment Engine Carburetor Needle Valve Kit for Craftsman 143988503 - Part 631021B

    Carburetor 1a70-5096 diagram

    Needle Seat

    Part #631021

    Replaced by #631021B

    Info Icon
    Manufacturer substitution
    This part replaces 631021. Substitute parts can look different from the original.
    This item is not returnable
    In Stock
    $11.38
    15% OFF Phone Price : $13.38Info Icon
    Minus Item
    Qty
    Plus Item
  • Lawn & Garden Equipment Engine Governor Lever for Craftsman 143988503 - Part 33454A

    Craftsman 4-cycle engine diagram

    Governor Lever

    Part #33454

    Replaced by #33454A

    Info Icon
    Manufacturer substitution
    This part replaces 33454. Substitute parts can look different from the original.
    This item is not returnable
    In Stock
    $11.77
    Minus Item
    Qty
    Plus Item
  • Lawn & Garden Equipment Engine Gasket Set for Craftsman 143988503 - Part 36450C

    Craftsman 4-cycle engine diagram

    Gasket

    Part #36450B

    Replaced by #36450C

    Info Icon
    Manufacturer substitution
    This part replaces 36450B. Substitute parts can look different from the original.
    This item is not returnable
    In Stock
    $24.03
    Minus Item
    Qty
    Plus Item
  • Starter Cup for Craftsman 143988503 - Part 35985C

    Craftsman 4-cycle engine diagram

    Starter Cap

    Part #35985B

    Replaced by #35985C

    Info Icon
    Manufacturer substitution
    This part replaces 35985B. Substitute parts can look different from the original.
    In Stock
    $17.33
    10% OFF Phone Price : $19.33Info Icon
    Minus Item
    Qty
    Plus Item
  • Washer for Craftsman 143988503 - Part 730324

    Craftsman 4-cycle engine diagram

    Washer

    Part #650690

    Replaced by #730324

    Info Icon
    Manufacturer substitution
    This part replaces 650690. Substitute parts can look different from the original.
    This item is not returnable
    In Stock
    $10.89
    Minus Item
    Qty
    Plus Item
  • Lawn & Garden Equipment Engine Washer for Craftsman 143988503 - Part 651080

    Craftsman 4-cycle engine diagram

    Lawn & Garden Equipment Washer

    Part #30590A

    Replaced by #651080

    Info Icon
    Manufacturer substitution
    This part replaces 30590A. Substitute parts can look different from the original.
    This item is not returnable
    In Stock
    $2.16
    Minus Item
    Qty
    Plus Item
  • Craftsman Lawn & Garden Equipment Engine Ignition Module for Craftsman 143988503 - Part 35135B

    Craftsman 4-cycle engine diagram

    Lamination

    Part #35135

    Replaced by #35135B

    Info Icon
    Manufacturer substitution
    This part replaces 35135. Substitute parts can look different from the original.
    In Stock
    $66.61
    8% OFF Phone Price : $72.61Info Icon
    Minus Item
    Qty
    Plus Item
  • Cap for Craftsman 143988503 - Part 640053

    Carburetor 1a70-5096 diagram

    Cap

    Part #640053

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

Craftsman Engine 143988503 FAQs

Craftsman engines are made by multiple manufacturers, not one single company; the maker depends on the specific Craftsman product and production run. For Craftsman lawn and garden equipment using engine model 143988503, the engine is commonly associated with Tecumseh-built small engines, and parts support is handled by matching the exact model number to the correct components.

How to identify who made your specific Craftsman engine

Because Craftsman is a brand used across many product lines, the most reliable way is to identify the engine by its model and specification numbers on the engine shroud or tag.

  • Find the engine model number stamped on the blower housing, valve cover, or an ID tag
  • Match the full engine model (and any spec/date code) to the parts list for 143988503
  • Compare carburetor and ignition parts to confirm the engine family
  • Use the parts breakdown to verify you are ordering the correct gasket, float, or ignition component

What you will typically see by manufacturer (quick guide)

Different OEMs used on Craftsman outdoor power equipment tend to have recognizable model-number patterns.

Common OEM Typical model number style What it helps with
Tecumseh Numeric engine models (often 6 to 9 digits) Carburetor and governor linkage matching
Briggs & Stratton 3-part format (Model-Type-Code) Tune-up parts and ignition matching
Kohler Command/Courage series identifiers Fuel system and charging system matching
Kawasaki FX/FR/FS series identifiers Carburetion and valve-train parts matching

Why it matters for parts and repairs

The engine maker determines the correct carburetor, ignition module, and fuel system parts. On model 143988503, common repair needs include fuel-related issues (hard starting, surging, flooding) where replacing carburetor wear items is often the fastest fix.

If you are troubleshooting fuel leaks or poor running, these model-matched parts are commonly involved:

Last updated: February 2026

The model number 143988503 is an engine model number, not the lawn mower model number. For a Craftsman mower that uses this engine, the mower’s model number is found on the mower deck or rear housing label; once you have it, you can match the correct mower parts and diagrams.

Where to find the mower model number

Look for a sticker or stamped tag on the mower itself (not the engine shroud). Common locations include:

  • Rear of the mower deck near the height adjusters
  • Top of the deck behind the engine
  • Under the rear discharge door (if equipped)
  • On the handle bracket or frame rail
  • Near the wheel area on the deck edge

Engine model vs. mower model (why they are different)

Your Craftsman 143988503 identifies the lawn and garden engine. The mower model number identifies the complete machine (deck, wheels, handle, controls), which is what you need for mower-specific parts like blades and drive components.

What you’re looking at Example format Used for
Engine model number 143988503 Engine parts like carburetor, air filter, ignition
Mower model number 917.XXXXXX (varies) Mower deck, blade, wheels, self-propel parts

If you’re repairing the engine right now

If the mower won’t start, surges, or runs rough, we typically start with fuel and carburetion items for model 143988503:

Why it matters

Using the mower model number prevents ordering the wrong blade, belt, or drive parts, while the engine model number (143988503) ensures you get the correct carburetor, ignition, and fuel system parts.

Last updated: February 2026

The Craftsman model 143988503 is an engine model number, not a complete riding mower model; it identifies the specific lawn and garden engine used on certain equipment. To confirm what riding mower it’s installed on (and that mower’s full engine specs), match the mower’s model number to the engine parts list for 143988503.

What you can confirm from this engine parts list

This model page supports that 143988503 is a Craftsman lawn and garden engine with common serviceable systems like carburetion, ignition, starting, and fuel delivery.

Common engine-related parts shown for 143988503 include:

  • Carburetor and carburetor rebuild components
  • Air intake filtration and gaskets
  • Recoil starter rope and starter housing
  • Ignition module and stop wire terminal
  • Fuel tank and fuel line

How to identify the exact engine on your riding mower

Use these checks to tie the mower to the correct engine family and parts:

  • Find the mower model number on the frame tag (often under the seat or on the rear fender area).
  • Find the engine model/spec numbers stamped on the engine shroud or blower housing.
  • Confirm the carburetor and air filter style match what’s listed for 143988503.
  • If the mower was repowered, rely on the engine tag, not the mower tag.

Quick parts clues (what they usually indicate)

Symptom or need Part on this model that often applies What it points to
Hard starting, surging Repair kit 632760B Carburetor varnish or worn seals
Fuel leaking from carb Needle seat 631021B Needle not sealing, debris in fuel
Won’t stay running Air filter 28424 Restricted airflow, rich running
No spark or intermittent spark Lamination 35135B Ignition module issue

Why it matters

Riding mower listings often describe horsepower, deck size, and transmission, but engine model numbers like 143988503 are what ensure you get the right carburetor parts, ignition parts, and fuel system parts for a repair.

Last updated: February 2026

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.…

Parts & More

Dishwasher
Drill/Driver
Dryer
Electric Leaf Blower
Freestanding Freezer
Front-Engine Lawn Tractor
Gas Leaf Blower
Gas Range
Gas Snowblower
Laundry Center
Office
Parts
Range Hood
Side-By-Side Refrigerator
Treadmill