Craftsman 143981002 engine Parts

A “Craftsman 6.75” label usually refers to the engine horsepower class, not the mower’s model number. For the mower identified as a Craftsman 21-inch 6.75-hp rotary walk-behind mower, the model number is 917377911. Use the mower’s model tag (not the engine tag) to confirm.

Where to find the correct model number

Look for the model label on the mower deck or rear housing; it is typically a sticker or metal tag.

• Check the top of the deck near the engine mounting area
• Check the rear flap or rear wheel height adjuster area
• Check the handle support brackets near the lower handle bolts
• Wipe dirt and grass off the label so all digits are readable
• Write down the full model number exactly as shown (all digits)

Mower model number vs. engine model number (why both matter)

Many Craftsman mowers use a separate engine model number (like 143981002) that identifies the engine only. The mower model number (like 917377911) identifies the full mower and is the one you use for most chassis and deck parts.

You are looking up	Example number	What it identifies	Best for finding
Mower model number	917377911	Complete mower	Deck, wheels, handle, drive parts
Engine model number	143981002	Engine only	Carburetor, ignition, starter, air filter

If you are actually trying to identify the engine

If your question is really about the engine on a Craftsman 6.75 mower, the engine model number is commonly on the blower housing or valve cover area. For Craftsman engine model 143981002, common service parts include:

• Craftsman lawn & garden equipment engine air filter 28424 for restricted airflow and hard starting
• Lawn & garden equipment engine fuel tank cap 37845 if the cap vent is plugged and fuel flow is affected
• Needle seat 631021B and Craftsman lawn & garden equipment engine carburetor float bowl 631867 for carburetor flooding or fuel leakage

Why it matters

Using the wrong model number is the fastest way to order the wrong part. The mower model number matches the mower’s frame and deck; the engine model number matches internal engine parts like the carburetor, ignition module, and starter.

Last updated: February 2026

Craftsman model 143981002 is an engine model number, and it was used across multiple years on different lawn and garden products. The exact build year is identified from the equipment’s model and serial number tag (not the engine parts list), then matched to the engine’s specification code.

How to find the exact year on your equipment

Look for the model and serial number label on the machine the engine is mounted on (mower, tiller, snowblower, etc.). Common locations include:

• Under the seat (riding mower)
• On the rear frame rail near the hitch plate
• On the deck shell near the discharge chute
• On the handle support or frame (walk-behind equipment)
• Near the engine shroud, but on the equipment frame, not the carburetor

What numbers matter (and what they tell us)

For Craftsman lawn equipment, the equipment tag usually provides the best date clues. The engine itself may also have a spec or date code stamped on the blower housing.

Where you find it	Example type of info	What it’s used for
Equipment model/serial tag	Model + serial	Determines production range and correct parts diagrams
Engine shroud stamping	Spec code, date code	Narrows the engine version and approximate build period
Carburetor/ignition part IDs	Part numbers	Confirms the correct configuration for tune-up and repair

Why it matters

The same 143981002 engine family can have different carburetor settings, ignition parts, and fuel system components depending on the exact spec code and production run. Getting the year right helps prevent ordering the wrong gasket, O-ring, or ignition module.

Parts that commonly vary by production run

If you are troubleshooting or refreshing the fuel and ignition system, these are common wear items that can differ by version:

• Needle seat 631021B (carburetor sealing and fuel metering)
• Craftsman lawn & garden equipment engine fuel tank cap 37845 (tank venting and fuel delivery)
• Lamination 35135B (ignition module component used for spark generation)
• Tecumseh lawn and garden equipment engine carburetor rebuild kit 632760B (carburetor service parts)

Last updated: February 2026

A typical lawn mower engine (including Craftsman model 143981002) is made up of fuel, air, ignition, and mechanical systems that work together to create combustion and turn the crankshaft. Common serviceable parts include the air filter, carburetor components, ignition module, starter parts, and internal engine parts.

Main engine systems and what they do

• Fuel system: stores fuel and delivers the correct fuel flow to the carburetor
• Air intake and filtration: cleans incoming air so dirt does not damage the cylinder and piston
• Ignition system: creates spark at the right time to ignite the air-fuel mixture
• Starting system: spins the engine fast enough to start combustion
• Mechanical rotating assembly: converts combustion pressure into rotating power

Common parts you will see on Craftsman 143981002

These are some of the most common parts customers replace or service on this engine:

• Lawn & garden equipment engine fuel tank cap 37845 (helps vent and seal the fuel tank)
• Craftsman lawn & garden equipment engine air filter 28424 (protects the engine from dust)
• Lawn & garden equipment engine air filter assembly 35403 (housing and filter support)
• Needle seat 631021B (carburetor sealing surface that helps control fuel level)
• Craftsman lawn & garden equipment engine carburetor float bowl 631867 (holds fuel for metering)
• Lamination 35135B (ignition module component used to generate spark)

Quick reference: parts by function

Function	What it affects	Example part on this model
Air filtration	Hard starting, black smoke, loss of power	Air filter, air filter assembly
Carburetion	Surging, flooding, won’t stay running	Needle seat, float bowl, carburetor O-ring
Ignition	No spark, misfire	Ignition module
Starting	Slow crank, no crank	Electric starter, starter motor armature
Internal compression	Low power, blow-by, oil use	Cylinder, piston assembly, piston ring set

Why it matters

Knowing the major engine parts helps you troubleshoot faster. For example, a dirty air filter often causes rich running and power loss, while carburetor sealing issues (needle seat or O-rings) commonly cause flooding, fuel leaks, or hard starting.

Last updated: February 2026

A Craftsman riding lawn mower can use several different engine types depending on the mower model; the Craftsman 143981002 we support here is an engine model number, not a complete riding mower model. In general, Craftsman riders commonly use single-cylinder or V-twin 4-cycle gasoline engines from makers such as Briggs & Stratton, Kohler, or Tecumseh/Lauson.

How to identify the exact engine on your Craftsman rider

Use the engine’s ID tag, not the mower deck size or seat style.

• Find the engine model and spec numbers stamped on the blower housing, valve cover, or a tag near the starter
• Match that engine model to the parts list; 143981002 is one such engine model
• If you only have the mower model number, use it to look up the mower first, then confirm the engine tag matches
• Compare key service parts (air filter, fuel cap, carburetor parts) to confirm you are in the right parts list

A common quick cross-check is the air cleaner style; for this engine, parts like the Craftsman lawn & garden equipment engine air filter 28424 and lawn & garden equipment engine air filter assembly 35403 are typical tune-up identifiers.

What “kind of engine” usually means (and what to expect)

Most Craftsman riding mower engines are:

• 4-cycle (no oil mixed in the gas)
• Air-cooled
• Carbureted (with a float bowl and needle/seat)
• Recoil start or electric start (many riders use electric start)

Typical engine types you’ll see on Craftsman riders

Engine type	What it’s like	Common symptoms when it needs service
Single-cylinder OHV	Simple, economical	Hard starting, surging, vibration
V-twin OHV	Smoother, more torque	Uneven idle, backfiring, power loss
Older flathead (L-head)	Common on older units	Hard starting, poor compression

Why it matters

The correct engine identification controls everything: the right carburetor parts (like a needle seat), ignition parts, starter parts, and even basic maintenance items. Ordering by “Craftsman riding mower” alone often leads to mismatched parts.

Last updated: February 2026