Craftsman 143978001 engine Parts

The Craftsman engine model 143978001 takes 27 oz of engine oil (about 0.84 quart). Filling to the correct level helps prevent hard starting, smoking, and internal engine wear.

Quick fill guidance (what we recommend)

• Park the equipment on a level surface and let the engine cool.
• Remove the dipstick or oil fill cap, then add oil slowly.
• Stop often and recheck the dipstick; do not overfill.
• If you accidentally overfill, drain a small amount and recheck.
• Change oil more often if you run in dusty conditions or heavy loads.

Oil capacity conversion

Measure	Amount
Ounces	27 oz
Quarts	0.84 qt
Cups	3.38 cups

What oil to use (typical for small 4-cycle lawn engines)

Most Craftsman lawn and garden engines of this type run best on:

• SAE 30 for warmer temperatures
• 10W-30 for wider temperature ranges
• 5W-30 synthetic for easier cold-weather starting

(Always fill to the dipstick mark; oil type does not change the 27 oz capacity.)

Why it matters

Running low on oil can cause rapid wear to the connecting rod and crankshaft surfaces; overfilling can cause smoking, plug fouling, and oil leaks. Keeping the level correct is one of the simplest ways to extend engine life.

Parts that often come up during oil and fuel maintenance

If you are doing a tune-up or chasing a running issue after an oil change, these model-matched parts are commonly involved:

• Craftsman lawn & garden equipment engine air filter 28424 (restricted air flow can mimic fuel problems)
• Lawn & garden equipment engine fuel tank cap 37845 (a bad vent can cause stalling)
• Craftsman snowblower engine deluxe extreme tune-up kit 730290 (common service items in one kit)

To order replacement parts for model 143978001, use the parts list for this model or search by model number on Sears PartsDirect.

Last updated: February 2026

A typical lawn mower engine (including Craftsman model 143978001) is built around fuel delivery, air intake, ignition, and mechanical rotating parts. Common serviceable items include the carburetor, air filter, fuel tank and cap, throttle/governor linkage, muffler, and starter components.

Main lawn mower engine systems (and what they do)

• Fuel system: stores and meters fuel into the engine (tank, cap, carburetor, float bowl, needle/seat)
• Air intake: filters air before it enters the carburetor (air filter, intake manifold)
• Ignition: creates spark at the right time (ignition module, spark plug)
• Starting system: spins the engine to start (recoil starter handle, electric starter parts if equipped)
• Exhaust: routes exhaust safely and reduces noise (muffler)
• Speed control: sets engine RPM under load (throttle link, governor linkage)

Common parts you may replace on Craftsman 143978001

These are examples of parts we commonly see customers replace for starting, surging, or fuel-leak issues:

• Craftsman lawn & garden equipment engine air filter 28424 (restricted airflow, rich running)
• Lawn & garden equipment engine fuel tank cap 37845 (venting problems, fuel smell)
• Craftsman lawn and garden equipment engine fuel tank 34156A (cracks, leaks)
• Craftsman lawn & garden equipment engine carburetor 632334A (hard start, surging)
• Lawn & garden equipment engine carburetor float bowl 631951 (leaks, varnish buildup)
• Needle seat 631021B (flooding, fuel overflow)

Quick “symptom to system” guide

Symptom	Most likely system	Parts to check first
Won’t start (after storage)	Fuel + ignition	Air filter, carburetor, ignition module
Starts then dies	Fuel delivery	Fuel cap venting, carburetor, float bowl
Surges at idle	Fuel/air mix	Air filter, carburetor, intake gasket
Loud exhaust	Exhaust	Muffler

Why it matters

Knowing the engine’s main systems helps you troubleshoot faster and avoid replacing the wrong part. For example, a “no start” can be fuel-related (varnished carburetor) or ignition-related (weak spark), and the fix is different.

Ordering the right parts

We recommend matching parts by the full model number 143978001 and comparing the part name and ID in the parts list. You can order replacement parts from the parts list for this model, or search by model number on Sears PartsDirect.

Last updated: February 2026

Craftsman lawn mowers use several different engine types depending on the mower model (walk-behind vs. riding) and the engine model number. For Craftsman engine model 143978001, you are looking at a specific lawn and garden engine; the exact horsepower and configuration vary by the equipment it’s installed on, so we match parts by the engine model number.

How to identify the exact engine on your mower

Use the engine’s model number (not just the mower’s brand) to confirm what you have. For this page, the engine model is 143978001.

• Find the engine ID tag or stamped numbers on the blower housing, valve cover, or recoil starter area
• Write down the full model number exactly as shown: 143978001
• Compare the parts diagrams and parts list for the engine model
• If your mower is hard to start or runs rough, confirm fuel and air delivery parts first

Common engine configurations you’ll see on Craftsman mowers

Most Craftsman mowers are powered by a small 4-cycle gasoline engine, but the layout depends on the mower style.

Mower type	Typical engine layout	What you’ll notice
Walk-behind mower	Single-cylinder, vertical shaft	Blade mounts directly under the engine
Riding mower	Single-cylinder or V-twin, vertical shaft	Belt-driven deck, larger air intake and muffler
Snowblower (some Craftsman-branded engines)	Single-cylinder, horizontal shaft	Auger drive system, winter starting features

Parts that help confirm what engine family you have

When you’re unsure of the exact engine configuration, the parts list usually points you in the right direction. For example, carburetion and governor parts are strong clues.

• Carburetor style and linkage layout (example: engine carburetor 632334A)
• Governor and throttle linkage (example: engine governor linkage 34667)
• Air intake and filtration (example: engine air filter 28424)
• Fuel system components (example: engine fuel tank 34156A)

Why it matters

Engine type determines the correct tune-up parts, carburetor settings, and linkage routing. Matching parts to Craftsman 143978001 prevents ordering the wrong carburetor, gasket, or fuel system component and helps restore starting and smooth running.

You can order replacement parts for Craftsman 143978001 from the parts list for this engine, or search by model number on Sears PartsDirect.

Last updated: February 2026

The model number for this Craftsman lawn and garden engine is 143978001. That full model number is what we use to match the correct carburetor, fuel system, ignition, and starter parts for your specific engine; you can also search it on Sears PartsDirect if you are looking up parts by model.

Where to find the model number on the engine

On most Craftsman small engines, the model number is stamped or printed on the engine shroud or blower housing (often near the recoil starter area). Look for a tag or stamped line that includes the model number.

• Check the recoil starter housing and nearby shroud surfaces
• Wipe off dirt and oil; the stamping can be faint
• Write the number exactly as shown (all digits)
• If you see multiple lines, capture them all (model, spec, date code)

Why this matters for ordering the right parts

Engines that look similar can use different carburetors, gaskets, and linkages. Using 143978001 helps ensure the part fits and the mounting holes, fuel passages, and governor/throttle connections line up correctly.

Common parts customers replace on model 143978001

Here are a few examples of parts on this model that are frequently involved in no-start, surging, or fuel leak issues:

Symptom	Common area to check	Example part on this model
Fuel leaking or flooding	Carburetor needle/seat	Needle seat 631021B
Runs rough or surges	Carburetor and intake sealing	Carburetor manifold gasket (33263)
Hard starting, black smoke	Air intake restriction	Air filter (28424)
Won’t rev correctly	Governor/throttle linkage	Governor linkage (34667)

Quick tip if you were expecting a different number

Sometimes people confuse the equipment model (like a tractor or snowblower model) with the engine model. For parts on this page, we use the engine model number 143978001.

Last updated: February 2026