What are the parts of a lawn mower engine?
On the Craftsman lawn tractor model 917273170, the engine system is made up of fuel, air, ignition, and mechanical components that work together to create power; you will also have safety interlocks and wiring that control starting and shutoff. For model-specific diagrams and service points, use the 917273170 owner's manual.
Main engine components (what they do)
- Fuel tank and fuel lines: store and deliver gasoline to the engine.
- Fuel filter: traps debris before it reaches the carburetor (a common cause of “loss of power” when dirty).
- Carburetor: mixes fuel and air; misadjustment can cause poor running and power loss.
- Air filter and air screen/fins: keep dirt out and help cooling; clogging can reduce power.
- Ignition system (spark plug, spark plug wire, ignition coil, flywheel magnets): creates spark to ignite the fuel mixture.
- Crankcase and internal parts (piston, crankshaft, valves): convert combustion into rotating power.
Related tractor systems people often call “engine parts”
These are not inside the engine, but they directly affect starting, running, and safety:
- Starter solenoid and starting circuit (clicking, no-crank symptoms): see solenoid with brass plunger 532146154.
- Ignition key and switch: enables the start/run circuit; see molded ignition key 532140403.
- Wire harness and safety interlock circuits: seat switch, brake/clutch switch, PTO switch; faults can stop the engine when you leave the seat.
Quick symptom-to-part map
| Symptom | Most likely area | What to check first |
|---|---|---|
| Loss of power | Fuel, air, ignition | Air filter, fuel filter, spark plug connection |
| Clicks but won’t crank | Starting circuit | Battery connections, solenoid, wiring |
| Backfires when shutting off | Throttle setting/ignition | Throttle position before shutdown |
Why it matters
Knowing which “engine part” you are dealing with helps you troubleshoot faster and order the right replacement; many running issues trace back to basic maintenance items (air, fuel, spark) before major internal engine repairs.
Last updated: February 2026
How much does it cost to replace a riding lawn mower engine?
Replacing the engine on a Craftsman riding lawn tractor like model 917273170 typically costs $260 to $1,800 installed, depending on the engine type, whether you reuse pulleys and wiring, and local labor rates. Plan on about 6 hours of labor for a full engine swap.
What drives the total cost
- Engine price: new, rebuilt, or used replacement engine
- Labor time: removal, transfer of parts, alignment, test run
- Extra parts: belts, pulleys, wiring repairs, mounting hardware
- Fuel system cleanup: common when old fuel caused starting issues
- Deck and drivetrain condition: worn components can add time and parts
Typical cost breakdown (what you are paying for)
| Cost item | Typical range | Notes |
|---|---|---|
| Replacement engine | $200 to $1,400 | Biggest variable; depends on brand and horsepower class |
| Labor | $300 to $900 | Often based on ~6 hours plus shop rate |
| Misc. parts and supplies | $20 to $200 | Hardware, belts, clamps, fluids, shop supplies |
Before you replace the engine, check these common “not the engine” causes
Many no-start complaints on riding mowers come from electrical or fuel issues, not a failed engine.
- Battery weak or cables corroded
- Starter solenoid clicking but not cranking
- Safety interlock switch problem (seat, brake, PTO)
- Old fuel or clogged fuel filter
- Ignition key or wiring harness issues
If the engine clicks but won’t turn over, follow our steps in riding lawn mower engine clicks but doesnt turn over video.
Parts you may end up replacing during an engine job
We often see these items replaced at the same time because they affect starting, cutting performance, or reliability:
- Solenoid with brass plunger 532146154 (starter solenoid)
- Molded ignition key 532140403 (lost or worn key)
- Lawn tractor wire harness 532179722 (damaged ignition wiring)
Why it matters
An engine replacement is one of the highest-cost repairs on a riding mower. Verifying the starting circuit and safety interlocks first can prevent spending hundreds on an engine when a solenoid, wiring, or adjustment fixes the problem. For model-specific maintenance and troubleshooting steps, use the owner's manual.
For parts pricing and availability for your 917273170, order from the parts list for this model or search by model number on Sears PartsDirect.
Last updated: February 2026
What year was Craftsman 917273170 made?
Craftsman model 917273170 was made across a production run (not a single year). The exact build year is identified from the tractor’s product identification label (typically under the seat or on the frame) and is also referenced in the model documentation; use the 917273170 owner's manual to confirm where to find and how to read that label.
How to find the build year on your tractor
We use the model number to get the correct parts list, but the serial/product number is what pins down the manufacture date.
- Park on a level surface, set the parking brake, and remove the key.
- Lift the seat and look for a product identification label (often under the seat pan).
- If it is not under the seat, check the frame rail near the engine or rear fender area.
- Write down the serial/product number exactly as shown.
- Use that number to determine the build date code (format varies by production batch).
What we can confirm from the model documentation
The documentation for this tractor clearly identifies it as TRACTOR model number 917.273170, which matches the Craftsman 917273170 model used for parts lookup and diagrams.
Common identifiers (what they mean)
| Identifier | Example | What it tells us |
|---|---|---|
| Model number | 917273170 | Which parts diagrams and assemblies apply |
| Serial/product number | (varies) | The specific unit and its build date |
| Deck size reference | 42-inch deck parts listed | Helps match blades, mandrels, and deck hardware |
Why it matters
The build year affects small but important fit details, especially on wear items and assemblies like mower deck components, steering hardware, and electrical parts. Confirming the serial/product number helps prevent ordering the wrong blade, mandrel, or harness.
Parts that often vary by production batch
If you are matching parts while you confirm the build year, these are common “check-your-serial” items:
- Blades (mulching vs high-lift)
- Mandrel and mandrel shaft assemblies
- Wire harness and ignition components
- Deck shields and brackets
Related parts you can match once the year is confirmed
For the 42-inch deck shown in the model documentation, these are examples of parts commonly replaced:
- Husqvarna lawn tractor mulching blade, 21-in 532134149
- Lawn tractor 42-in deck high-lift blade 532138971
You can order replacement parts for Craftsman 917273170 from the parts list for this model, or search by model number on Sears PartsDirect.
Last updated: February 2026
Who makes Craftsman engines?
For Craftsman lawn tractor model 917273170, the engine is a Kohler engine; Craftsman used Kohler as the engine supplier on this tractor platform. To confirm the exact Kohler engine model and spec for your unit, match the engine ID tag to the engine information in the 917273170 owner's manual.
How to confirm the engine manufacturer on 917273170
Use the engine’s identification tag; it is the fastest way to verify the exact Kohler model and order correct maintenance parts.
- Find the engine ID label on the blower housing, valve cover, or engine shroud
- Write down the model and spec (Kohler commonly uses a spec number)
- Compare those numbers to the engine section in the 917273170 owner's manual
- Clean the label first; dirt and grass can hide key digits
- Use the engine ID when selecting tune-up parts (spark plug, air filter, fuel filter)
What the ID numbers typically tell you
| ID item you record | What it’s used for | Why it matters |
|---|---|---|
| Engine model | Identifies the Kohler engine family | Ensures correct service parts fit |
| Spec number | Pinpoints the exact configuration | Prevents wrong carburetor or starter parts |
| Serial number | Tracks production run | Helps match diagrams and revisions |
Why it matters for repairs and parts ordering
Engine parts are engine-specific, even when the tractor model is the same. Confirming the Kohler ID helps you avoid mismatched starting and ignition parts.
- No-crank issues often trace to the starter circuit
- A weak connection can mimic a bad solenoid
- Safety interlocks can stop cranking even with a good battery
If you are troubleshooting a click-no-crank symptom, the solenoid with brass plunger 532146154 is a common starting-circuit part used on many Craftsman tractor setups, and the riding lawn mower engine clicks but doesnt turn over video walks through the checks step by step.
You can order replacement parts from the parts list for model 917273170, or search by model number on Sears PartsDirect.
Last updated: February 2026
What engine does Craftsman riding mower use?
Craftsman riding mowers use a range of engines depending on the exact model. For Craftsman lawn tractor model 917273170, the equipment is specified as a 17.5 HP tractor with a 42-inch mower deck, electric start, and a 6-speed transaxle; use the engine ID tag on your tractor to confirm the engine’s make and model. Details are listed in the 917273170 owner's manual.
How to identify the exact engine on model 917273170
Use the engine’s identification label to get the information needed for tune-up and repair parts.
- Find the engine ID label on the blower housing, valve cover, or near the starter
- Write down the model, type, and code (common label fields)
- Clean the label with a rag and mild cleaner; avoid scraping the sticker
- Compare the label info to the engine/specifications section in the manual
- Keep the engine code handy when ordering ignition, carburetor, or gasket parts
What the manual specs tell you (and what they affect)
The manual’s headline specs help you separate engine issues from deck or drive issues.
| Manual spec for 917273170 | What it impacts | Examples of related problems |
|---|---|---|
| 17.5 HP engine | Power under load, starting behavior | Stalling in tall grass, surging, hard starting |
| Electric start | Battery, solenoid, starter circuit | Clicking, no-crank, slow crank |
| 6-speed transaxle | Ground speed and drive engagement | Won’t move, slips, noisy drive |
| 42-inch deck | Cut quality and discharge | Uneven cut, vibration, poor bagging |
Why it matters
The tractor model number (917273170) tells us the platform and deck size, but the engine label is what ensures you get the correct engine-specific parts and service settings (spark plug, air filter, carburetor kit, valve clearance).
Parts and DIY help that match common engine questions
- If you hear a click but the engine will not crank, follow riding lawn mower engine clicks but doesnt turn over video
- If you suspect a starting-circuit issue, a common service part on this tractor platform is the solenoid with brass plunger 532146154
- For blades and deck-related maintenance, match parts to the 42-inch deck (for example, lawn tractor 42-in deck high-lift blade 532138971)
- Order parts from the list for model 917273170, or search by model at Sears PartsDirect
Last updated: February 2026





