How to read a Craftsman mower serial number?
On Craftsman gas walk-behind mower model 917377171, the serial number is used to identify your exact unit for parts and service; you’ll find it on a decal on the rear of the mower housing. Use the serial number exactly as printed when ordering parts or looking up specifications in the 917377171 owner’s manual.
Where to find the serial number (917377171)
The model and serial numbers are printed on a decal attached to the rear of the lawn mower housing.
- Look at the back of the mower deck (rear housing area)
- Wipe off grass and dirt so every character is readable
- Write down both the model number and serial number
- Record the date of purchase as well (helpful for warranty and service)
How to interpret the serial number
Craftsman serial-number formats vary by mower and production run, so the most reliable approach is to use the serial number as an identifier (not as a guaranteed date code).
Here are the most common ways serial numbers are used:
- Unit identification for correct parts lookups
- Production tracking for the manufacturer
- Service reference when troubleshooting or ordering assemblies
Quick check: “date code” claims
Some online guides suggest the first digits represent a build date (month, day, year). That pattern can appear on some equipment, but it is not universal across all Craftsman mowers.
| What you’re trying to do | Best method | Why |
|---|---|---|
| Confirm the exact mower version | Use the full serial number | Prevents ordering the wrong blade, belt, or control parts |
| Find operating specs (oil type, plug gap, torque) | Use the manual specs section | Specs are model-based, not serial-based |
| Order common wear items | Match parts by model and diagrams | Wear items can vary by deck and drive setup |
Why it matters
A single digit off in the serial number can point to a different parts list. Using the serial number exactly as printed helps us match the correct blade, drive belt, wheels, and hardware for your Craftsman 917377171.
Last updated: January 2026
Should I use 87 or 91 gas for lawn mower?
For the Craftsman gas walk-behind mower model 917377171, regular 87-octane gasoline is the right choice for normal mowing. Using 91-octane will not add power or improve reliability; focus instead on using fresh fuel and following the fuel and maintenance guidance in the 917377171 owner's manual.
Recommended fuel for model 917377171
Use fuel that helps the engine start easily and prevents carburetor problems.
- Use fresh, clean unleaded gasoline (87 octane is standard).
- Avoid stale fuel; old gas is a common reason a mower “does not start.”
- If you suspect water in fuel, drain the tank and refill with fresh gasoline.
- Store gasoline in an approved container and keep the mower away from ignition sources when fueling.
- For off-season storage, follow the manual’s storage steps so fuel does not cause starting issues later.
When higher octane does (and does not) help
Octane mainly relates to resistance to knock in high-compression engines. Most walk-behind mower engines are designed to run correctly on regular fuel.
| Fuel choice | What you get | Best use case |
|---|---|---|
| 87 octane (regular) | Correct performance for typical mower engines | Everyday mowing |
| 91 octane (premium) | No meaningful power gain in most mowers | Not needed unless your engine label/manual specifically calls for it |
If your mower is hard to start after fueling
The troubleshooting chart for this mower points to fuel quality and ignition basics.
- Replace or service the air filter if it is dirty.
- Drain and replace fuel if it is stale.
- Drain fuel and carburetor if there is water in fuel.
- Check the spark plug wire connection; replace the spark plug if needed (the manual calls for yearly replacement and a .030-inch gap).
Why it matters
Using the correct fuel (and keeping it fresh) reduces no-start problems, rough running, and carburetor varnish. For model 917377171, fuel freshness and routine tune-up items usually make a bigger difference than octane.
Last updated: January 2026
What model number is the Craftsman 917377171?
The model number for this Craftsman gas walk-behind lawn mower is 917.377171 (often written without the dot as 917377171). You’ll also see it printed on the mower’s model tag and on the parts list in the 917377171 owner's manual.
Where to find the model number on the mower
We recommend confirming the model number directly from the mower before ordering parts like a blade, belt, or throttle control.
- Check the model tag on the mower deck (top or rear area of the deck is common)
- Look near the rear discharge door or rear skirt area
- Check the handle support area if the deck tag is missing
- Match the number format exactly (with or without the dot)
Model number formats you may see
Both formats refer to the same mower.
| How it may appear | What it means |
|---|---|
| 917.377171 | Standard model tag format |
| 917377171 | Same model number without punctuation |
Why it matters
Craftsman walk-behind mowers can look similar across years, but parts can differ by model. Using the exact model number helps ensure the correct fit for items like the drive system, wheel adjusters, and cutting blade.
Related parts you might match by model
If you’re ordering common wear items, match them to model 917377171 first.
- Lawn mower blade 532406713 (cutting performance)
- Belt 532157769 (self-propel drive)
- Throttle 532700417 (engine speed control)
Last updated: January 2026





