Craftsman 917378550 gas walk-behind lawn mower Parts

The Craftsman gas walk-behind lawn mower model 917378550 uses 20 oz (about 0.6 qt) of engine oil for a normal refill. Add oil slowly and use the dipstick to set the final level at the full mark.

• Use SAE 30 for typical warm-weather mowing (common for many small 4-cycle mower engines).
• Park the mower on a level surface before checking or filling.
• Add about 3/4 of the oil first, then recheck the dipstick.
• Do not overfill; excess oil can cause smoking and hard starting.
• Recheck the level after the first short run, then top off if needed.

Correct oil level protects the engine from rapid wear. Low oil can damage the engine quickly; overfilled oil can foam, leak, or foul the spark plug.

The oil quantity and maintenance guidance are listed in the 917378550 owner's manual.

Last updated: February 2026

On the Craftsman 917378550 gas walk-behind lawn mower, the most common problems we see are no-start conditions, loss of power, and poor or uneven cutting. These issues are usually tied to basic maintenance items (spark plug, air filter, blade condition) or grass buildup under the deck; our 917378550 owner's manual troubleshooting chart walks you through the quickest checks.

• Won’t start: spark plug wire off, bad spark plug, or a safety/control issue with the control bar
• Loss of power: cutting too much grass at once, dirty air filter, grass packed under the deck, oil level too high, or walking speed too fast
• Uneven cut: worn/bent/loose blade, wheels set to different heights, or debris under the mower housing
• Hard to push or bogging down: cutting height too low for conditions, heavy/wet grass, or deck packed with clippings
• Vibration: loose blade hardware or damaged blade

1. Disconnect the spark plug wire before working near the blade.
2. Verify the control bar is held against the handle when starting.
3. Check the spark plug connection and condition.
4. Inspect the blade for bends, heavy wear, or looseness; replace if damaged.
5. Set all wheels to the same cutting height.
6. Clean packed grass from the underside of the deck.

If your mower is cutting poorly, a fresh blade often makes the biggest difference. For self-propelled “won’t move” complaints, the ground drive belt is a common wear item.

Most “big” mower problems start as small maintenance issues. Keeping the blade sharp, the deck clean, and the engine tuned reduces strain on the engine, improves cut quality, and helps prevent repeated no-start and power-loss cycles.

Last updated: February 2026

For the Craftsman gas walk-behind lawn mower model 917378550, we use SAE 10W30 engine oil (API service SF through SJ), and the oil capacity is 18.5 ounces. Fill to the full mark on the dipstick and avoid overfilling.

• Oil type: SAE 10W30 (API-SF to API-SJ)
• Oil capacity: 18.5 oz
• Fuel capacity/type (for reference): 1.0 quart, unleaded regular
• Change interval: about every 25 hours of operation or each season

For the exact procedure and dipstick reading method, follow the steps in the 917378550 owner's manual.

1. Park the mower on a level surface and let the engine cool.
2. Remove the oil fill cap/dipstick.
3. Add oil slowly; start with about 3/4 of a 20 oz bottle, then wait 1 minute.
4. Check the dipstick level (rest the cap on the tube when checking, do not thread it in).
5. Top off in small amounts until it reads full.

Using the correct viscosity and filling to the proper level helps prevent hard starting, smoking on startup, and accelerated engine wear during mowing season.

Last updated: February 2026

For your Craftsman gas walk-behind lawn mower model 917378550, the most reliable way to get the right replacement part is to shop by the exact model number and match the part name and number to your diagram and parts list in the 917378550 owner's manual. This helps you avoid look-alike parts that do not fit.

• Use the mower’s model number (917378550) and the part description when searching
• Confirm the part on the exploded-view diagram and parts list in the manual
• Replace worn maintenance items together when it makes sense (blade, belt, air filter, spark plug)
• Keep your serial number handy; it is typically listed on a decal on the rear of the mower housing
• If you need help identifying hardware, match size and thread type before ordering

These are examples of model-matched parts that are commonly needed during repairs and tune-ups:

Ordering by model number and verifying against the manual prevents fitment problems and repeat repairs. It also helps you choose the right maintenance parts so your mower starts easier, cuts cleaner, and runs more reliably.

Last updated: February 2026

On the Craftsman gas walk-behind lawn mower model 917378550, we find the model and serial numbers on a decal on the rear of the lawn mower housing. Use those numbers when ordering parts or checking the correct blade, belt, or control cable in the 917378550 owner's manual.

The identification decal typically includes:

• Model number (for this mower: 917378550)
• Serial number (unique to your mower)
• A space to record date of purchase
• Basic specs such as fuel and oil capacity (varies by engine)

1. Turn the mower off and let the engine cool.
2. Stand behind the mower at the handle.
3. Look down at the rear of the mower deck/housing for a decal.
4. Wipe off grass and dirt; use a flashlight if needed.
5. Write down the model and serial number exactly as shown.

Use this checklist before assuming it is missing:

• Clean the area with a damp rag (avoid soaking decals)
• Check for a decal on the rear-facing surface of the deck
• Look for paint overspray or grass staining hiding the print
• Take a photo and zoom in to read faded characters

The model number narrows parts down to the correct configuration for your mower, especially for items that commonly vary by version, such as the ground drive belt, wheel parts, and control cables.

Last updated: February 2026

For the Craftsman gas walk-behind lawn mower model 917378550, the mower is a Craftsman-branded unit sold by Sears; the most reliable way to identify the actual manufacturer and the correct replacement parts is to match the model number and parts list in the 917378550 owner's manual.

Craftsman mowers have been produced by more than one outdoor power equipment maker over the years, so the model number and parts breakdown are the deciding factors.

Use these checks:

• Confirm the full model number on the rear housing decal: 917378550
• Compare the illustrated parts list pages to your mower’s handle, deck, wheels, and drive system
• Look for engine branding on the recoil cover (engine maker can differ from mower maker)
• Match common service parts by description (blade, belt, control cable, wheels)
• Use the manual’s “Repair Parts” section to cross-check part descriptions and key numbers

The documentation for Craftsman 917378550 identifies it as a Craftsman rotary lawn mower, 5.5 horsepower, power-propelled, with a 21-inch multi-cut deck. Those specs help you match the correct parts and service procedures even when manufacturer branding varies by production run.

Different manufacturers used different deck stampings, wheel adjusters, and drive systems under the Craftsman name. Matching by model 917378550 prevents ordering a “looks similar” part that will not fit.

Examples of model-matched parts you can use for identification:

• Lawn mower engine zone control cable 532184588 (control cable assembly)
• Lawn mower ground drive belt, 3/8 x 32-1/2-in 532175436 (self-propel drive belt)
• Husqvarna lawn mower 21-in deck 3-in-1 blade 532189028 (cutting blade)

Last updated: February 2026