What model number is a Craftsman 91725640 lawn mower?
The model number for this Craftsman riding mower is 91725640. On Sears PartsDirect, 91725640 identifies a Craftsman front-engine lawn tractor (14-hp super tractor), which is different from similarly numbered walk-behind mower models.
Where to find the model number on the mower
Most Craftsman riding mowers and lawn tractors have a model tag or sticker in one of these spots:
- Under the seat (seat pan area)
- On the frame near the rear fender
- Along the left or right side of the chassis
- Near the engine compartment or hood hinge area
- On the deck housing (less common for the main model tag)
Why “91725640” can be confused with other Craftsman models
Craftsman model numbers can look similar across different product types. For example, a walk-behind mower and a riding tractor can both start with “917”, but they use different parts and diagrams.
Quick comparison
| Item you have | Correct model format | What it affects |
|---|---|---|
| Riding mower / lawn tractor | 91725640 | Steering, drive, deck, wheels, belts |
| Walk-behind mower | Different model number | Blade adapter, handle controls, small wheels |
Parts lookup tip (why it matters)
Using the exact model number ensures you get the right diagrams and compatible replacement parts for your Craftsman 91725640, such as the ground drive belt, steering hardware, and wheel components.
If you are repairing the front end or steering, common wear items include bearings, washers, and tie-rod ends; for example, the wizard lawn tractor axle flange bearing 532009040 is one of the model-matched parts listed for this tractor.
Before ordering parts, confirm:
- The model tag reads 91725640 (all digits)
- The part location on your tractor matches the diagram section you are using
- You are replacing like-for-like hardware (bolt length, washer type, nut style)
Last updated: February 2026
Is it worth replacing a lawn mower engine?
Yes, replacing the engine on your Craftsman 91725640 front-engine lawn tractor is worth it when the tractor’s deck, frame, steering, and drive system are still solid and the total swap cost stays well below the cost of replacing the whole machine. It is not worth it when the tractor has major drivetrain or deck damage, or multiple worn systems.
Quick decision checklist
- The mower deck is structurally sound (no major rust-through or cracks)
- The transmission and drive belt system operate normally (no slipping, grinding, or loss of drive)
- Steering and front axle are tight enough to track straight (no severe wobble)
- You can source the correct engine and mounting hardware for this tractor
- The total cost (engine + incidentals) stays under about 50% of a comparable replacement tractor
What to inspect on a Craftsman 91725640 before you buy an engine
Focus on the parts that are expensive or time-consuming to fix. If several of these are already failing, an engine swap usually turns into a full rebuild.
| Area to check | What “good” looks like | What makes replacement less worthwhile |
|---|---|---|
| Deck shell | Solid metal, minimal corrosion | Rust holes, cracked welds, bent shell |
| Drive system | Moves smoothly forward/reverse | Won’t move, loud transaxle noise |
| Steering/front end | Tracks straight, limited play | Excessive slop, uneven tire wear |
| Electrical | Starts reliably, wiring intact | Burnt connectors, hacked wiring |
Costs you should plan for (beyond the engine)
Even a straightforward swap typically needs a few extras.
- New fuel line and fuel filter
- Fresh oil, air filter, and spark plug for the new engine
- Throttle/choke cable adjustments or replacement
- New belts or idlers if they are worn (common on older tractors)
- Hardware you may replace while you are in there (washers, lock nuts)
If you are already chasing vibration, wheel wobble, or steering looseness, it often makes sense to address wear items at the same time, such as the wizard lawn tractor axle flange bearing 532009040 or a hub bolt 596218701.
Why it matters
An engine swap only pays off when it extends the life of a tractor that is otherwise dependable. If the deck, drivetrain, and steering are already near end-of-life, the new engine will not prevent the next expensive failure.
Last updated: February 2026
Who makes Craftsman mower motors?
Craftsman mower engines are commonly supplied by major small-engine manufacturers; across many Craftsman riding mowers and lawn tractors (including model 91725640), you’ll typically see engines built by Briggs & Stratton, Kohler, or Kawasaki, depending on the specific mower’s engine family and production run.
How to identify who made the engine on your Craftsman 91725640
Use the engine’s ID tag, not the mower model number. The engine maker and exact engine model are printed on a label or stamped plate on the engine shroud, valve cover area, or blower housing.
- Look for an engine brand name (Briggs & Stratton, Kohler, Kawasaki)
- Write down the engine model, type/spec, and code/serial
- Match those numbers when buying tune-up parts (filters, belts, hardware)
- If the label is dirty, wipe it and use a flashlight to read stamped characters
- Keep the numbers with your maintenance records for faster parts lookup later
Why the manufacturer can vary
Craftsman tractors are assembled with engines sourced from different suppliers over time. Even within the same mower family, the engine brand can change based on availability, horsepower class, and emissions configuration.
| What you’re checking | Where to find it | Why it matters |
|---|---|---|
| Mower model number (91725640) | Frame tag under seat or on chassis | Identifies tractor parts diagrams and chassis parts |
| Engine model/spec/code | Engine label or stamped plate | Identifies engine service parts and correct tune-up kit |
Parts note for this model
If you’re chasing a “motor problem” that’s actually drive or chassis related (vibration, wobble, poor tracking), we often start by inspecting wear items like bearings, pulleys, and wheel hardware. For example, a worn axle bearing can mimic drivetrain issues; see the wizard lawn tractor axle flange bearing 532009040 if you’re servicing the front axle area.
Why it matters
Using the correct engine manufacturer and engine spec prevents ordering the wrong carburetor parts, ignition parts, or filters, and it speeds up troubleshooting when the tractor won’t start, runs rough, or lacks power.
Last updated: February 2026
What engine does Craftsman riding mower use?
For the Craftsman riding mower model 91725640, the engine is a single-cylinder gasoline riding mower engine in the 14 HP class (this model is listed as a “14-hp super tractor”). For the exact engine brand and engine model number, match the engine ID tag to the parts listing for your tractor.
How to identify the exact engine on model 91725640
Look for an engine identification label, then use that information to confirm the correct engine parts.
- Check the blower housing (top/front of the engine) for a stamped tag or sticker
- Also check the valve cover, starter housing, or engine shroud
- Record the engine model, type, and code (common on Briggs & Stratton engines)
- If the label is missing, record the mower model number 91725640 and compare diagrams/parts by section
- Use the tractor’s serial number if your parts list is split by production range
Common engine brands used on Craftsman tractors (what to expect)
Craftsman tractors in this era commonly used engines from a few major suppliers. Your 91725640 is most often found with one of these types:
| Engine brand (common) | Typical configuration | What the ID tag usually shows |
|---|---|---|
| Briggs & Stratton | Single-cylinder | Model / Type / Code |
| Kohler | Single-cylinder | Spec number / serial |
| Tecumseh (older units) | Single-cylinder | Model / spec |
Why it matters
The tractor model number (91725640) gets you to the right chassis and deck parts, but engine parts are matched to the engine’s own model/spec code. That prevents ordering the wrong carburetor, ignition parts, gaskets, or tune-up items.
Parts on this model page that relate to engine operation
Even when the engine itself is fine, drive and chassis parts can cause “no power” symptoms under load. These parts are commonly involved:
- V-belt 583785001 (slipping belt can mimic low engine power)
- Flat idler 583772001 (idler pulley issues reduce belt tension)
- Ammeter 532124900 (helps diagnose charging and electrical output)
Last updated: February 2026





