How old is my mower by serial number?
On Craftsman rotary lawn mower model 917377561, the serial number is used for identification, but it typically does not contain a simple, reliable “date code” you can decode into an exact build date. The most accurate way to document the mower’s age is to record the serial number and use your purchase date as the age reference in your maintenance records (as shown in the 917377561 owner's manual).
Where to find the serial number on model 917377561
The model and serial numbers are listed on a decal attached to the rear of the lawn mower housing.
- Look at the rear of the mower deck (housing) for the decal
- Record both the model number (917377561) and the serial number
- Write down the date of purchase for your records
- Keep the information with your maintenance log (oil changes, blade service, belt checks)
How to estimate age when you only have the serial number
If you need an age estimate (for parts planning or resale), use these practical checks.
- Use the date of purchase as the baseline if you have a receipt or warranty paperwork
- Check for engine model and engine serial on the engine itself (engine makers often use their own dating systems)
- Compare the mower’s configuration to the parts list (for example, self-propel drive components like the belt 532157769 or cutting components like the lawn mower mulching blade 532406713)
- If you are servicing the drive system, note that wear patterns on the belt, pulleys, and wheels often reflect overall age and use
Quick reference: what each number tells you
| Number you have | What it identifies | Best use |
|---|---|---|
| Model number (917377561) | The exact mower design | Ensures correct parts diagrams and parts fit |
| Mower serial number | The specific unit | Helps with identification and service history |
| Engine model/serial | The engine build | Helps match engine tune-up parts and engine-specific info |
Why it matters
Knowing the correct model number and keeping the serial number with your purchase date helps us match the right Craftsman walk-behind mower parts (blade adapter, drive belt, control cable) and helps you plan maintenance like blade care and seasonal tune-ups.
Last updated: January 2026
How to find Craftsman model number?
On the Craftsman rotary lawn mower model 917377561, the model number is typically printed on a sticker on the back of the mower deck, usually between the lower handle mounts. Use that exact number when ordering parts or checking specifications in the 917377561 owner's manual.
Where to look on the mower
Check these common label locations on walk-behind mowers like model 917377561:
- Back of the deck (rear of the cutting housing), between the lower handle brackets
- Top rear of the deck near the bagger opening (if equipped)
- Side of the deck near a rear wheel height adjuster area
- Under the rear discharge door (on some deck designs)
What information to write down
We recommend recording all of the following from the sticker:
- Model number (example: 917377561)
- Serial number (helps match production variations)
- Product number (if shown)
- Engine model number (often different from the mower model)
Quick ID checklist
| Item | What it identifies | Used for |
|---|---|---|
| Mower model number | The mower deck and drive system | Correct Craftsman parts diagrams and parts |
| Serial number | Build run and revisions | Matching the right version of parts |
| Engine model number | The engine itself | Engine parts like carburetor or recoil starter |
Why it matters
Craftsman walk-behind mowers can look similar across multiple model runs, but parts like the drive belt, control cable, blade adapter, and fasteners can vary. Using the exact model number helps us match the correct diagrams and avoid ordering the wrong part.
Last updated: January 2026
Should I use 87 or 91 gas for lawn mower?
For the Craftsman 917377561 gas walk-behind mower, we recommend using fresh regular unleaded 87 octane in normal conditions. Higher octane (like 91) does not add power in small mower engines; fuel freshness and proper storage matter more for easy starting and smooth running.
What to use (and what to avoid)
- Use 87 octane regular unleaded from a busy station (fresher fuel).
- Avoid stale gas; old fuel is a common cause of no-start and rough running.
- Keep the fuel can clean and rust-free; rust and dirt in fuel cause problems.
- Clean up spills before starting; let a hot engine cool before refueling.
- If the mower will sit, use a fuel stabilizer and store fuel properly.
Quick comparison
| Fuel choice | Best use case | What you should expect |
|---|---|---|
| 87 octane (regular) | Everyday mowing | Normal performance and reliable operation |
| 91 octane (premium) | Not needed for octane reasons | No added power; higher cost |
| Fresh fuel + stabilizer | Storage and seasonal equipment | Fewer starting issues after sitting |
If you are having starting or running problems
The mower manual troubleshooting points to fuel condition as a top cause. If your mower will not start or runs poorly, focus on these fuel-related checks first:
- Drain and replace stale fuel with fresh gasoline.
- Check for water in fuel (drain tank and carburetor, then refill).
- Inspect and service the air filter and spark plug as part of routine maintenance.
For model-specific safety and fueling steps (including cooling the engine before refueling), follow the 917377561 owner's manual.
Why it matters
Using the right fuel is less about octane and more about preventing varnish, corrosion, and water contamination that can clog the carburetor and make the engine hard to start, especially after storage.
Last updated: January 2026





