Owner’s manual
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What kind of gas do I put in my lawn mower?
For the Craftsman lawn mower model 917388981, we recommend using fresh, regular unleaded gasoline (typically 87 octane) and avoiding old or contaminated fuel. This mower ships without gas in the engine, so you will need to add fuel before first use; follow the fuel and safety guidance in the 917388981 owner's manual.
What fuel to use (and what to avoid)
- Use fresh regular unleaded gasoline from a clean, approved gas can.
- E10 (up to 10% ethanol) is commonly used in walk-behind mowers; keep it fresh and do not store it long-term.
- Avoid stale fuel (fuel left sitting for weeks or months), which is a common no-start cause.
- Avoid fuel contaminated with water, rust, or dirt; it can cause hard starting and rough running.
- Do not mix oil into the gas; this mower uses a 4-cycle engine (oil goes in the crankcase, not the fuel).
Quick checklist before you fill the tank
- Let the engine cool and refuel outdoors.
- Use a clean container; replace a gas can that is rusting.
- Fill carefully and wipe up spills.
- If the mower has been stored with fuel, drain and replace with fresh gas before troubleshooting a no-start.
Fuel freshness guide
| Situation | What we recommend | Why |
|---|---|---|
| New fuel purchase | Buy only what you will use soon | Reduces stale-fuel problems |
| Fuel stored from last season | Replace with fresh fuel | Old fuel can prevent starting |
| Rusty/dirty gas can | Replace the can | Rust and dirt cause fuel system issues |
Why it matters
Fuel quality directly affects starting, power, and engine life. The manual’s troubleshooting list includes stale fuel and water in fuel as common reasons a mower will not start, so using fresh, clean gasoline prevents many avoidable repairs.
Related DIY help
- If you suspect old fuel is the issue, use our how to keep lawn mower gas from going bad tips to reduce starting problems.
Last updated: January 2026
What model number is the Craftsman 917388981?
The model number is 917.388981 (often written without the dot as 917388981) for this Craftsman gas walk-behind mower. You can confirm it on the cover of the 917388981 owner's manual, where it’s listed as “Model No. 917.388981.”
Where to find the model number on the mower
Most Craftsman walk-behind mowers list the model number on an ID label. Check these common spots:
- Rear of the deck near the discharge opening
- Top of the deck behind the engine
- Near the height-adjustment area by a rear wheel
- On the handle support/bracket area
- Inside the rear door area (near the bagging opening)
Model number formats you may see
You may see the same model shown in slightly different formats; they refer to the same mower.
| How it may appear | What it means |
|---|---|
| 917.388981 | Standard Craftsman format shown in the manual |
| 917388981 | Same model number without punctuation |
| 917 388981 | Same digits with a space |
Why it matters
Using the exact model number helps us match the correct diagrams and parts for your mower, such as the upper handle 532194179 or the lawn mower zone control cable 532183281. It also helps ensure you get the right engine-related maintenance parts for the Briggs and Stratton engine used on this model.
Last updated: January 2026
Where is Craftsman's model number?
On the Craftsman walk-behind mower model 917388981, the mower’s model and serial numbers are printed on a decal on the rear of the lawn mower housing. For diagrams and the exact label location, use the 917388981 owner's manual.
Where to look on the mower
Check these common spots on the mower body (not the engine):
- Rear of the deck (back side of the mower housing), usually centered or slightly offset
- Near the rear discharge area or rear wheel height adjuster area
- On the top rear lip of the deck where grass and debris collect
- On a flat section of the deck where a decal can stick cleanly
Mower model number vs. engine model number
This mower has two different IDs that are easy to mix up:
| What you’re identifying | Where it’s found | What it’s used for |
|---|---|---|
| Mower model number (917388981) | Decal on rear of mower housing | Ordering Craftsman mower parts (handle, wheels, deck parts) |
| Engine model number (example shown in manual: 125K02-0578-E1) | Stamped/printed on the engine | Ordering engine-specific parts (carburetor, ignition, recoil parts) |
Tips if the decal is hard to read
- Wipe the area with a damp rag first; dried grass can hide the print.
- Use a flashlight at a low angle to make faded lettering stand out.
- Take a close-up photo and zoom in to read the numbers.
- Record both the model and serial number before the decal wears further.
Why it matters
Using the correct model number helps us match the right Craftsman walk-behind mower parts for your exact deck and handle configuration, so parts like the upper handle 532194179 fit correctly.
Last updated: January 2026
