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How old is my mower by serial number?
For a Craftsman gas walk-behind lawn mower model 917378440, the serial number can often be decoded to estimate the build date, but the format varies by the engine and deck manufacturer. We recommend using the date-code guidance in the 917378440 owner's manual and matching the serial tag details to the most common code patterns.
Where to find the serial number on a walk-behind mower
Look for a sticker or stamped tag on the mower, then write down the full serial number exactly as shown.
Common locations include:
- Rear of the deck near the discharge chute
- Top of the deck near the engine mounting area
- Behind the engine or near the muffler heat shield
- On the handle bracket or rear frame crossbar
- On the engine shroud (engine serial is separate from the mower deck serial)
How to decode the serial number (common patterns)
Many mowers use a date code embedded in the first part of the serial number, but the order differs.
| Common date-code pattern | What it usually means | Example (illustrative) |
|---|---|---|
| MMDDYY | Month, day, year | 041523 = Apr 15, 2023 |
| YYMMDD | Year, month, day | 230415 = Apr 15, 2023 |
| YYWW (week) | Year and production week | 2316 = week 16 of 2023 |
| MMYY | Month and year | 0423 = Apr 2023 |
Quick checks that usually work
- If you see a clear 6-digit block, try reading it as MMDDYY first, then YYMMDD.
- If you see a 4-digit block, try YYWW (year/week) or MMYY (month/year).
- If the mower deck tag and engine tag disagree, use the deck tag to date the mower and the engine tag to date the engine.
Why it matters
Knowing the approximate manufacture date helps us match the correct Craftsman parts (blade adapter, drive belt, wheels, control cable) and avoid ordering look-alike parts that changed mid-production.
Parts you may replace more often as the mower ages
If you are refreshing an older 917378440, these are common wear items to inspect:
- Drive system parts (belt, drive control)
- Blade mounting hardware and adapter
- Wheels and wheel dust covers
- Zone control cable (operator presence control)
If you are troubleshooting self-propel issues, the lawn mower wont move troubleshooting video motion drive failure guide is a good next step.
Last updated: January 2026
What are the most common issues with 917378440?
The most common problems we see on the Craftsman 917378440 gas walk-behind mower are no-start or hard-start conditions, poor cutting quality, and self-propel/drive issues (won’t pull or slips). Most fixes come down to basic tune-up, blade and adapter inspection, and checking the drive belt and wheels; use the 917378440 owner's manual for model-specific adjustments and safety steps.
Common symptoms and what usually causes them
- Won’t start / starts then dies: stale fuel, dirty air filter, fouled spark plug, or a carburetor that needs cleaning.
- Runs rough / surges: restricted fuel flow, dirty carburetor, or governor/throttle linkage out of adjustment.
- Poor cut (uneven, ragged, scalping): dull/bent blade, loose blade hardware, worn blade adapter, or deck height set unevenly.
- Self-propel not working: worn or stretched drive belt, worn drive wheel traction, or drive gears/bearings binding.
- Vibration: damaged blade, debris wrapped around the blade area, or a worn blade adapter.
Parts on this model that often relate to these issues
If you’re troubleshooting cutting or drive problems, these model-matched parts are common checkpoints:
- Lawn mower blade adapter 581547901 (cut quality, vibration)
- Lawn mower ground drive belt, 3/8 x 32-1/2-in 532175436 (self-propel slipping or no drive)
- Husqvarna lawn mower drive wheel, 8 x 2-in 532180775 (loss of traction)
- Lawn mower zone control cable 532133107 (engine stop/kill control not operating correctly)
Quick checks we recommend before buying parts
- Use fresh fuel and confirm the fuel shutoff (if equipped) is open.
- Inspect the blade for bends and sharpen or replace if damaged.
- Tip the mower safely (spark plug wire off) and check the blade adapter for cracks or wobble.
- Check the drive belt for glazing, cracking, or slack.
- Verify both rear wheels spin freely and have good tread.
Troubleshooting guide (fast reference)
| Symptom | Most likely area | Typical fix |
|---|---|---|
| Won’t start | fuel/ignition | tune-up, clean carburetor |
| Uneven cut | blade/height | sharpen blade, level height |
| No self-propel | belt/wheels | replace belt, inspect drive wheels |
| Excess vibration | blade/adapter | replace damaged blade or adapter |
Why it matters
Catching wear early prevents bigger failures, like stripped drive gears or crankshaft damage from running a bent blade. Regular maintenance also improves starting, cut quality, and mower life.
Last updated: March 2026
What model number is the Craftsman 917378440?
The model number for this Craftsman gas walk-behind lawn mower is 917378440. You’ll find it on the mower’s model/serial tag; matching that number is the fastest way to get the correct parts list, diagrams, and maintenance specs in the 917378440 owner's manual.
Where to find the model number on the mower
On most Craftsman walk-behind mowers, the model/serial tag is on the deck or rear housing area. Check these common spots:
- Top of the mower deck near the engine
- Rear of the deck behind the engine
- Near the height adjuster area by a rear wheel
- On the rear discharge door area (if equipped)
- On the handle bracket near the deck
What to do if you see multiple numbers
It’s normal to see several identifiers (engine numbers, deck numbers, or product codes). Use this quick guide:
| What you see on the tag | What it means | What to use for parts |
|---|---|---|
| Model number (example: 917378440) | Mower’s main identifier | Use this for parts lookup |
| Serial number | Unique unit ID | Helpful for service records |
| Engine model/type/code | Engine identifier | Use for engine-specific parts |
| Product code or marketing name | Retail listing info | Not reliable for parts |
Why it matters
Parts like the drive belt, blade adapter, and control cable can vary by mower version. Using 917378440 helps ensure you get the right fit the first time, whether you’re replacing a wear item or doing a tune-up.
Common parts that depend on the correct model number
- Drive system parts (belt, pulleys, drive control)
- Blade mounting parts (adapter, fasteners)
- Handle and control components (bail, zone control cable)
- Wheels and height adjusters
If you’re servicing the blade mount, the lawn mower blade adapter 581547901 is one example of a model-matched part where the correct model number matters.
Last updated: January 2026
