Owner’s manual
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Where to find model number on Craftsman lawn mower?
On a Craftsman gas walk-behind mower like model 917378402, the model number is printed on the mower’s ID label (or stamped on a plate) attached to the mower deck or frame. We use that number to match the correct parts list and diagrams in the 917378402 owner's manual.
Common places to check on model 917378402
Look for a sticker, metal tag, or stamped plate in these spots:
- On the rear of the mower deck near the back wheels
- On the side of the deck near a rear wheel
- On the frame/handle mounting area (where the handle bolts to the deck)
- Near the engine mounting area on the deck (not on the plastic engine cover)
- Under grass buildup; wipe the deck clean to reveal the label
Quick tips to find it faster
- Tip the mower back only if the fuel tank is low and the spark plug wire is disconnected.
- Use a flashlight and a rag; the label is often dirty or faded.
- Write down the full model number exactly as shown (for example, 917.378402 may appear with a dot).
What to record from the label
| What you see | Why we need it |
|---|---|
| Model number (example: 917378402 or 917.378402) | Ensures the correct Craftsman parts diagrams |
| Product number or serial number (if listed) | Helps confirm the exact build/version |
| Engine model (if shown separately) | Helps when ordering engine-specific parts like ignition or carburetion items |
Why it matters
Craftsman walk-behind mowers often share similar decks and handles, but the drive system, blade adapter, and controls can vary by model. Using the exact model number helps prevent ordering the wrong items such as a premium blade 532406706 or drive components.
Last updated: January 2026
What model number is the Craftsman 917378402?
The model number is 917.378402, commonly written without the dot as 917378402. This identifies your specific Craftsman gas walk-behind lawn mower for ordering the correct parts and matching the correct diagrams and procedures in the Craftsman 917378402 owner's manual.
Where to find the model number on the mower
We recommend confirming the number on the mower’s model tag so parts like the drive belt, control cable, and wheel hardware match your exact build.
- Check the model tag on the mower deck (often near the rear or side of the deck)
- Look near the handle mounting area or rear discharge door area
- Wipe off grass and dirt; the tag can be hard to read when dirty
- Record the full number exactly as shown (including the dot, if present)
Why the model number matters for parts and diagrams
The Craftsman 917378402 parts list and exploded views in the manual are organized by this model number, including drive system and gear case breakdowns.
| What you’re doing | Why the model number matters | Example for this model |
|---|---|---|
| Ordering a replacement blade | Ensures correct length and mounting style | Premium blade 532406706 |
| Fixing self-propel issues | Matches the correct belt and drive control parts | Lawn mower ground drive belt, 3/8 x 33-9/16-in 532169778 |
| Replacing wheel/drive hardware | Prevents mismatched fasteners and wheel parts | Lawn mower e-ring 812000058 |
Quick tip for writing it down
Use both formats in your notes:
- 917.378402 (as shown in many manuals/labels)
- 917378402 (as used on many parts sites and search fields)
Why it matters
Using the exact model number prevents ordering the wrong Craftsman mower parts and saves time on repairs like blade replacement, drive belt service, and wheel adjuster work.
Last updated: January 2026
Should I use 87 or 91 gas for lawn mower?
For the Craftsman 917378402 gas walk-behind lawn mower, we recommend using fresh regular unleaded gasoline (87 octane). Higher octane (like 91) does not add power or improve reliability in a mower engine; fuel freshness and proper storage matter far more. See the 917378402 owner's manual for fuel and safety details.
What to use (and what to avoid)
- Use fresh, clean, regular unleaded 87 octane.
- Avoid stale fuel; old gas is a top cause of no-start and rough running.
- Avoid fuel contaminated with water or dirt (often from old cans).
- Use a clean, approved gas can; replace it if it starts to rust.
- Add fuel stabilizer if the mower will sit for weeks or over the off-season.
Quick guidance by situation
| Situation | Best choice | Why |
|---|---|---|
| Normal weekly mowing | 87 octane | Runs correctly in small mower engines |
| Mower sits 30+ days | 87 + stabilizer | Helps prevent stale-fuel starting problems |
| Hard starting after storage | Drain/refill with fresh 87 | Manual troubleshooting lists stale fuel and water in fuel as common causes |
Why it matters
Most mower performance and starting issues come from fuel condition, not octane. The manual troubleshooting section specifically calls out stale fuel and water in fuel as causes of a mower that will not start, and it also advises not storing gasoline from one season to the next.
Related parts and maintenance tips
If you are doing seasonal maintenance, these model-matched parts are commonly involved in safe, reliable mowing:
- Premium blade 532406706 (blade condition affects cut quality and engine load)
- Lawn mower grass bagger 532410677 (bagging performance depends on airflow and deck condition)
- Keep the underside of the deck clean to maintain airflow and reduce clumping.
For storage prep, follow the fuel-handling and storage steps in the manual, and use the guide how to winterize a lawn mower for a simple checklist.
Last updated: January 2026
What is the lifespan of a Craftsman lawn mower?
Most Craftsman gas walk-behind lawn mowers like model 917378402 typically last 8 to 10 years with normal residential use and routine maintenance. Regular tune-ups, clean fuel practices, and timely replacement of wear items (blade, belt, air filter, spark plug) are what usually determine whether you reach or exceed that range.
What affects lifespan the most
- Maintenance schedule: oil changes, air filter service, blade care, and lubrication
- Fuel quality and storage: stale gas and ethanol-related issues shorten engine life
- Operating conditions: sandy soil, heavy dust, steep hills, and frequent wet mowing increase wear
- Wear parts replaced on time: blade, drive belt, wheels, cables, and fasteners
- Deck care: keeping the underside clean helps prevent corrosion and performance loss
Typical lifespan by use pattern
| Use pattern | Typical lifespan | What usually ends it first |
|---|---|---|
| Light residential (small yard, seasonal) | 10+ years | Fuel system neglect, corrosion |
| Average residential (weekly mowing) | 8 to 10 years | Drive wear, engine starting issues |
| Heavy residential (large yard, long season) | 5 to 8 years | Drive system wear, deck damage |
Maintenance habits that extend mower life
Use the 917378402 owner's manual to follow the correct service intervals and procedures. These habits make the biggest difference:
- Run fresh fuel and avoid storing fuel for long periods
- Keep the blade sharp and balanced; replace it when bent or badly worn
- Clean grass buildup from the deck after mowing (when safe to do so)
- Replace drive components when slipping starts (common on self-propelled mowers)
Parts that commonly wear on this model
If performance drops, these are common replacement items for Craftsman 917378402:
- Premium blade 532406706 (cut quality and engine load)
- Lawn mower ground drive belt, 3/8 x 33-9/16-in 532169778 (self-propel drive strength)
- Lawn mower grass bagger 532410677 (bagging performance and airflow)
Why it matters
A mower that is maintained and repaired with the right parts usually costs far less per year to own than replacing it early. On the other hand, if the deck is rusting through or the engine has low compression, replacement is typically the better long-term value.
Last updated: January 2026
