Craftsman 917388380 21" 6.0-hp rotary lawn mower Parts

For this Craftsman walk-behind mower, the model number is 917388380. On the mower itself, you’ll typically find the model and serial number on a decal attached to the rear of the mower housing; confirm it matches 917388380 before ordering parts.

We recommend checking these common locations first:

• Rear of the mower housing (decal/label on the back of the deck)
• Near the handle mounting area on the deck
• On the side or top of the mower deck, depending on production run
• In your documentation, such as the 917388380 owner’s manual

Your mower has a mower model number and an engine model number; they are not the same.

We use the mower model number to match the correct diagrams and manufacturer-approved parts. Using the engine model number by itself can lead to ordering the wrong blade, cable, or hardware for the Craftsman deck.

• Write down the full model number exactly as shown
• Record the serial number too (helpful for production variations)
• If the decal is worn, use the manual’s model identification section as a cross-check

Last updated: January 2026

For Craftsman model 917388380, we recommend using fresh, clean regular unleaded gasoline with a minimum of 87 octane; higher octane (such as 89) is not required for normal operation. This matches the fuel guidance in the 917388380 owner’s manual.

• Use 87 octane (regular unleaded) or higher if that’s what you have available.
• Use fresh fuel; buy only what you can use in about 30 days.
• Do not mix oil with gasoline (this is a 4-cycle engine).
• Avoid old fuel; stale gas is a common no-start and rough-running cause.
• For storage longer than about 30 days, plan to drain the tank or use a fuel stabilizer.

Using the correct octane helps your Craftsman mower run as designed, but fuel freshness matters more than octane. Stale or water-contaminated gas can cause hard starting, surging, and loss of power.

If you’re still having trouble after adding fresh 87 octane, check common maintenance items first:

• Air filter condition
• Spark plug condition and connection
• Fuel age and signs of water contamination
• Built-up grass/debris under the deck (can load the engine)

If you’re doing a tune-up, a compatible kit can simplify routine service; see the briggs & statton tune-up kit 5140B.

Last updated: January 2026

For the Craftsman 917388380, the owner’s manual doesn’t set a dollar threshold for when repair becomes “too expensive,” so we can’t give a model-specific cost cutoff. In practice, it’s usually cheaper to repair when the issue matches the manual’s routine maintenance or troubleshooting items; replacement is more likely when damage is extensive or repairs stack up.

The 917388380 owner’s manual includes a maintenance schedule and a troubleshooting chart that point to several fixable, service-type causes (for example: dirty air filter, stale fuel, bad spark plug, loose blade, or grass buildup under the deck). Those are typically repair scenarios because they involve inspection, cleaning, adjustment, or replacing common wear parts.

Common manual-listed issues that are often repairable:

• “Does not start” from dirty air filter, stale fuel, or bad spark plug
• “Loss of power” from grass buildup under the mower or cutting too much grass
• “Poor cut” from a worn, bent, or loose blade, or uneven wheel height settings
• “Excessive vibration” from a worn/bent/loose blade
• “Starter rope hard to pull” from blade dragging in grass or a broken blade adapter

Use this quick comparison to keep the decision grounded in what you can verify on the mower.

If vibration or hard starting traces back to the blade mounting area, a frequent wear item is the blade adapter; for this model, see lawn mower blade adapter 581547901.

A mower that vibrates, has a dragging blade, or has damaged guards can be unsafe and can cause additional wear. Using the manual’s troubleshooting steps first helps you avoid paying for unnecessary parts or labor.

Last updated: January 2026