Craftsman 917378641 gas walk-behind lawn mower Parts

On Craftsman model 917378641, the serial number itself usually does not decode into a clear build date; instead, we use the serial number to identify the exact production run and then confirm the manufacturing timeframe using the model and serial decal information in the 917378641 owner's manual.

The manual specifies that the model and serial numbers are on a decal on the rear of the lawn mower housing.

• Look at the rear of the mower deck/housing for the decal
• Write down both the model number (917378641) and the full serial number
• Record your date of purchase if you still have it (receipt, warranty paperwork)
• If the decal is dirty, wipe it gently so every digit is readable

Many walk-behind mowers do not use a consumer-friendly “MMDDYY” serial format. For this mower, the most reliable approach is to combine what you know (purchase date, wear level, and parts history) with the model/serial identification.

• Use the date of purchase as your baseline if you have it
• Check whether the mower has had major wear items replaced (blade, belt, wheels)
• Compare your mower’s configuration to the illustrated parts list in the manual
• If you are ordering parts, match parts by model number + serial to avoid wrong-fit items

If you are trying to judge age by maintenance history, these are common replacement items on 917378641:

Knowing the approximate age helps us pick the right replacement parts and plan maintenance. As mowers get older, normal wear in the drive system, wheels, and blade can cause poor cut quality, vibration, or reduced self-propel performance.

Last updated: January 2026

For the Craftsman 917378641 gas walk-behind lawn mower, we recommend using fresh, clean unleaded gasoline from a busy station. For best starting and fewer fuel-system problems, use regular unleaded with 10% ethanol or less and add fuel stabilizer if the mower will sit for 30 days or longer (see the 917378641 owner's manual).

• Use fresh unleaded gasoline (regular grade is fine).
• Choose fuel with 10% ethanol or less (E10); avoid higher-ethanol blends.
• Buy only what you will use in 30 days.
• If storing the mower, treat fuel with stabilizer or run the tank and carburetor dry before storage.
• Never pour engine or carburetor cleaner into the gas tank; it can damage the fuel system.

The manual guidance for this mower is to prevent stale fuel issues by emptying the fuel system for longer storage.

• Shut the engine off and let it cool.
• Fill outdoors; wipe up spills.
• Do not overfill; leave a little expansion space.
• Confirm the engine has the correct oil level (this mower ships without oil or gas).

Old fuel can separate and form acids during storage, which leads to hard starting, rough running, and carburetor problems. Using fresh unleaded gas and handling storage correctly keeps your Craftsman 917378641 more reliable season to season.

Last updated: January 2026

A “Craftsman 6.75” label refers to the engine size, not one single mower model number. For the Craftsman gas walk-behind mower covered here, the model number is 917.378641 (often written without the dot as 917378641); you can confirm it in the 917378641 owner's manual.

Use the mower’s ID label, not the engine cover decal.

• Look for a sticker or metal tag on the rear deck, near the height adjusters, or on the handle bracket area
• The mower model is typically formatted like 917.XXXXXX
• The engine may have its own separate model and type numbers (those are not the mower model)
• Write down the full mower model number and any product number if shown
• Match that number to the parts diagrams in the manual

We use the mower model number to pull the exact parts list and diagrams for your deck, wheels, and drive system. For example, the 917.378641 parts breakdown lists items like the lawn mower throttle control 532700644 and the lawn mower ground drive belt 532169778, which can vary across similar-looking Craftsman mowers.

Last updated: January 2026