Craftsman 917388740 gas walk-behind lawn mower Parts

For the Craftsman 917388740 gas walk-behind lawn mower, we recommend using fresh, clean regular unleaded gasoline with a minimum of 87 octane; 89 octane is fine but not required for normal operation. Use fuel you can burn within about 30 days to keep starting and performance consistent.

• Use: Regular unleaded 87 octane or higher
• Avoid: Mixing oil into the gasoline (this is not a 2-cycle fuel mix)
• Avoid: Old fuel that has been sitting for weeks or months
• Be careful with: Alcohol-blended fuels; they can attract moisture during storage

For the exact fueling and storage guidance for this mower, follow the 917388740 owner's manual.

Using the right octane helps, but fresh fuel prevents more problems than octane changes.

• Buy only what you will use in 30 days
• Fill the tank to the bottom of the filler neck; do not overfill
• Wipe up spills right away and keep fuel away from ignition sources
• If the mower will sit 30 days or longer, run it until the fuel system is empty (tank, fuel lines, carburetor)

Old or moisture-contaminated gasoline can cause hard starting, rough running, and fuel-system damage. Sticking with 87+ octane and keeping fuel fresh protects the carburetor and helps the engine run cooler and more reliably.

Last updated: February 2026

On the Craftsman gas walk-behind lawn mower model 917388740, the most common problems are no-start conditions (often fuel, spark, or control bar related), loss of power from airflow or deck buildup, poor cut from blade or height issues, and excessive vibration from a damaged blade or crankshaft. See the 917388740 owner's manual for the troubleshooting chart and maintenance schedule.

• Won’t start: empty or stale fuel, carburetor varnish from old gas, disconnected spark plug wire, worn spark plug, loose blade bolt, or a control bar issue
• Loss of power: dirty air filter, grass and debris packed under the deck, cutting too much grass, oil level problems, or walking speed too fast
• Poor cut (uneven): worn or bent blade, uneven wheel height settings, or deck buildup
• Excessive vibration: loose or bent blade, broken blade adapter, or bent crankshaft (often after striking an object)
• Starter rope hard to pull: blade dragging in heavy grass, blade adapter problems, or crankshaft damage

1. Drain and refill with fresh gasoline if fuel is old.
2. Inspect and service the air filter (clean or replace).
3. Check the spark plug condition and reconnect the plug wire firmly.
4. Tip the mower safely (spark plug wire off) and clean under the deck.
5. Verify the control bar is fully depressed to the handle during starting.

If you find blade wobble, impact damage, or repeated loosening, the blade mounting hardware and adapter are frequent culprits.

• Consider inspecting the lawn mower blade adapter 581547901 if the blade won’t stay tight or the mower vibrates.

Running with a bent blade, broken blade adapter, or heavy deck buildup can cause poor cutting, hard starting, and vibration that accelerates wear on the engine and drive components.

Last updated: February 2026

The most common repairs on the Craftsman 917388740 gas walk-behind lawn mower are basic maintenance and wear-item replacements: fixing no-start issues (fuel, spark, air), restoring cutting quality (blade and blade hardware), and correcting drive or control problems (cables, belts, wheels). Use the Craftsman 917388740 owner's manual to match symptoms to the right checks.

• Won’t start or starts then dies: old fuel, dirty air filter, fouled spark plug, or fuel system restriction.
• Rough running or surging: stale fuel, dirty filter, or carburetor-related issues (this model’s carburetor is not adjustable).
• Poor cut quality or vibration: dull, bent, or damaged blade; loose blade bolt; worn blade adapter.
• Hard to pull starter rope: blade obstruction, engine issue, or recoil starter problem.
• Self-propel won’t move (if equipped): worn or stretched belt, drive wear, or wheel/axle issues.
• Controls feel wrong: stretched/binding throttle cable or loose handle hardware.

These specs from the manual help you do the most common service correctly:

• Gasoline capacity: 1.6 quarts (unleaded regular)
• Oil capacity: 20 oz; oil type SAE 30 (above 32°F) or SAE 5W-30 (below 32°F)
• Spark plug: Champion RJ19LM, gap 0.030 in
• Blade bolt torque: 35 to 40 ft-lbs

Wear items are normal on walk-behind mowers (blades, blade adapters, belts, air cleaners, spark plugs). If you’re chasing vibration or a blade that won’t stay tight, the blade mounting hardware matters too.

• Consider inspecting the lawn mower blade adapter 581547901 when replacing or servicing the blade.

Most “repair” calls on a gas mower are really tune-up and safety issues. A sharp, properly tightened blade and clean fuel/air/spark reduce hard starting, stalling, vibration, and uneven cutting, and they help prevent damage from running the mower out of adjustment.

Last updated: February 2026

The model number for a Craftsman 917388740 lawn mower is 917.388740 (often written without the dot as 917388740). You can confirm it on the model decal on the rear of the mower housing and in the 917388740 owner's manual.

Look for the identification decal in these common spots:

• Rear of the mower housing (most common location)
• Near the rear discharge door area
• On the deck close to the handle mounting points
• In your paperwork, including the owner’s manual

Craftsman model numbers are commonly shown with or without a dot; both refer to the same mower.

Using the exact model number helps us match the correct diagrams and parts for your specific Craftsman gas walk-behind lawn mower. Even small model-number differences can change the blade adapter, throttle cable routing, or wheel and axle hardware.

If you are ordering common wear items for this model, match parts by diagram callout and description; for example, the lawn mower throttle cable 532168552 is listed for model 917.388740 in the repair parts section.

Last updated: February 2026