Owner’s manual
View engineShould I use 87 or 91 gas for lawn mower?
For the Craftsman lawn mower model 917387670, use fresh regular unleaded 87-octane gasoline for normal operation. Higher octane (like 91) is not required for performance; the bigger priority is clean, fresh fuel and safe storage practices per the 917387670 owner's manual.
What to use (and what to avoid)
- Use 87 octane regular unleaded from a busy station (fresher fuel).
- Avoid stale fuel; old gas is a common no-start cause.
- Keep the fuel can clean and rust-free; rust and dirt contaminate fuel.
- Do not store gasoline from one season to the next.
- If the mower has been sitting, drain old fuel and refill with fresh gas.
Quick comparison: 87 vs 91 for a walk-behind mower
| Fuel choice | Best use case | What you will notice |
|---|---|---|
| 87 octane (regular) | Everyday mowing | Normal starting and power when fuel is fresh |
| 91 octane (premium) | Not needed for most mowers | Typically no added benefit versus 87 |
If your mower will not start after fueling
Old or contaminated gasoline can cause starting problems. The manual troubleshooting guidance points to fuel quality issues (stale fuel, water in fuel) as common causes.
- Check that you have fresh fuel in the tank
- If fuel is old, empty the tank and refill with fresh gasoline
- Inspect the spark plug wire connection and spark plug condition
- Check for a loose blade or damaged blade adapter (it can affect operation)
Why it matters
Using the right fuel is less about octane and more about preventing stale fuel and contamination, which helps your Craftsman 917387670 start reliably and reduces carburetor and engine issues during the mowing season and after storage.
Last updated: January 2026
What are the most common issues with 917387670?
On the Craftsman 917387670 walk-behind mower, the most common problems we see are no-start or hard-start conditions, poor cutting quality, and drive or control issues caused by normal wear in the blade, blade adapter, wheels, and control cable. Use the 917387670 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 carburetor varnish
- Rough running / surging: partially clogged carburetor, old fuel, restricted airflow
- Poor cut (ragged grass, vibration): bent or dull blade, loose hardware, damaged blade adapter
- Uneven cut height: worn wheels, bent wheel bracket, deck buildup
- Blade won’t stay engaged (zone control issues): stretched or binding control cable, misadjusted handle controls
Quick checks we recommend first
- Shut the mower off, let it cool, and disconnect the spark plug wire.
- Drain old fuel and refill with fresh fuel (use the correct fuel type listed in the manual).
- Inspect the blade and mounting stack for damage or looseness.
- Check wheel condition and height adjusters for wear or binding.
- Verify the zone control cable moves freely and returns fully.
Parts that commonly wear on this model
If you’re troubleshooting cutting or vibration issues, these parts are frequent fixes:
- Lawn mower blade 532406713 (dull, bent, or out of balance)
- Lawn mower blade adapter 581547901 (rounded drive features, wobble at the blade)
- Lawn mower zone control cable 532183281 (binding, stretched, or broken)
- Lawn mower wheel 583720101 (worn tread or wobble)
| Symptom | Most likely area | Typical fix |
|---|---|---|
| Vibration | Blade or adapter | Replace blade and inspect adapter |
| Ragged cut | Blade | Sharpen or replace blade |
| Uneven height | Wheels/brackets | Replace worn wheel or bracket |
| Engine stops when handle released | Zone control | Adjust or replace cable |
Why it matters
A worn blade or blade adapter can cause vibration that loosens fasteners and accelerates deck and wheel wear. Keeping the cutting system tight and balanced improves cut quality and helps the engine run smoother.
Last updated: March 2026
What model number is a Craftsman 917387670 lawn mower?
The model number for this Craftsman walk-behind lawn mower is 917.387670 (often written without the dot as 917387670). You’ll find it on the model/serial decal on the rear of the mower housing; it also appears on the cover of the 917387670 owner's manual.
Where to find the model number on the mower
Look for a decal or label on the rear of the lawn mower housing. We recommend writing down both the model and serial number before ordering parts.
- Check the rear of the deck/housing (not the handle)
- Wipe off grass and dirt so the decal is readable
- Record the model number and serial number exactly as shown
- Use the model number to match parts like the blade, blade adapter, and control cable
Why the exact model number matters
Craftsman model numbers can look very similar, but small differences can change the correct blade, fasteners, or handle hardware. Using 917387670 helps ensure parts diagrams and replacements match your mower.
| What you’re checking | What it’s used for | Example on this model |
|---|---|---|
| Model number | Identifies the mower version for parts lookup | 917.387670 / 917387670 |
| Serial number | Helps identify production run details | Found on the same decal |
| Part ID | Identifies the exact replacement part listing | 532406713 |
Common parts that depend on the correct model
If you’re ordering maintenance parts, match them to model 917387670 first.
- Lawn mower blade 532406713 (blade fit and deck size must match)
- Blade mounting hardware (nuts, washers, adapters)
- Control and safety cables
- Wheels and wheel brackets
Why it matters
The right model number prevents wrong-part returns and helps you get the correct fit, safe operation, and proper cutting performance.
Last updated: January 2026
