Craftsman 917378450 gas walk-behind lawn mower Parts

The model number for this Craftsman gas walk-behind lawn mower is 917.378450 (often written without the dot as 917378450). You can confirm it on the model identification label and in the 917378450 owner's manual.

Where to find the model number on the mower

We use the model number to match the correct parts diagrams and hardware for your mower (handle parts, drive system parts, wheels, and deck components).

• Check the model tag/label on the mower deck or rear housing area
• Look for a number formatted like 917.378450
• Write it down exactly; a single digit change can point to a different parts list
• Use the model number when ordering common wear items like belts, cables, and wheel parts

Model number vs. other numbers you might see

Some mowers also show engine numbers or product names; those are not the same as the mower model number.

What you see	What it means	What to use it for
917.378450	Mower model number	Parts lookup for the Craftsman mower
Engine model/type code	Engine identification	Engine-specific parts (carburetor, ignition, etc.)
Serial number	Unique unit ID	Warranty or service records

Why it matters

The Craftsman 917378450 parts list is model-specific; it controls fit for items like the drive system and handle controls. For example, if you are troubleshooting self-propel issues, the correct drive components depend on the exact model.

• Drive issues often involve the belt or control cable
• Handle and control parts vary by model year and configuration
• Wheel and height adjuster hardware can differ between close model numbers

If you are ordering a drive-related part for this model, one common example is the control cable assembly 583134601 (listed in the model parts breakdown).

Last updated: January 2026

On a Craftsman gas walk-behind lawn mower like model 917378450, the model number is typically printed on the mower’s ID label on the rear of the deck near the lower handle mounting area. Confirm the exact location and label format in the 917378450 owner's manual.

Where to look on the mower

Check these common spots first (clean the area if needed):

• Rear of the cutting deck, between or near the lower handle mounts
• Back edge of the deck, just above the discharge opening or rear door area
• Side of the deck near a wheel height adjuster bracket
• On the handle support bracket area (near the handle bolts/knobs)

What you should write down

We recommend recording both identifiers so you can match parts correctly.

Item to record	What it’s used for	Example format
Model number	Identifies the mower version for parts diagrams	917378450
Serial number	Helps confirm production run details	Letters and numbers

Tips if the label is hard to read

If the sticker is faded or covered with grass and oil residue:

• Wipe with a damp rag and mild soap; avoid harsh solvents that can erase printing
• Use a flashlight at an angle to make embossed or faded text easier to see
• Take a close-up photo and zoom in to read the characters
• Look for a second label on the deck if the first one is damaged

Why it matters

The model number (and often the serial number) ensures you get the right Craftsman parts for your exact deck and drive configuration, such as the correct control cable, wheel hardware, or drive belt routing shown in the parts diagrams.

Last updated: January 2026

On Craftsman gas walk-behind lawn mower model 917378450, the serial number is printed on a decal on the rear of the mower housing; once you locate it, you can use the serial format on that decal (and the date-of-purchase field in the manual) to determine the mower’s approximate build timeframe. See the 917378450 owner's manual for the exact label location and recording details.

Where to find the serial number on model 917378450

The manual specifies the model and serial numbers are on a decal on the rear of the mower housing. Use these quick checks:

• Look at the rear of the deck housing, near the discharge door area
• Clean grass and dirt off the decal so every digit is readable
• Write down the full serial number exactly as shown (including any letters)
• Record your date of purchase as a second reference point
• Take a photo of the decal before it fades further

How to estimate the mower’s age from the serial number

Craftsman walk-behind mowers and their engine suppliers can use different serial formats. Use this practical approach:

• Check for a date code embedded in the serial (often a year and week, or year and month)
• If the mower has a Briggs & Stratton engine, the engine itself may have its own date code separate from the mower serial
• Compare the serial/date code estimate to your purchase date for a realistic age range

Quick decoding guide (common patterns)

What you see in the serial	What it usually means	What to do
A 2-digit year like YY	Manufacturing year	Confirm with the next digits (month or week)
A 4-digit block like YYWW	Year + production week	Convert week to an approximate month
A 6-digit block like MMDDYY or YYMMDD	Month/day/year	Read as a full build date

Why it matters

Knowing the mower’s age helps us match the right Craftsman parts (blade adapter, zone control cable, drive belt) and plan maintenance intervals like oil changes, blade service, and tune-ups.

Last updated: January 2026

For a Craftsman 917378450 gas walk-behind lawn mower, it’s usually cheaper to repair when the problem is routine maintenance or a wearable part (blade, belt, spark plug, air filter). Replacement makes more sense when the engine or drive system needs major work and the repair total approaches half the cost of a comparable new mower.

A practical cost rule we use

If the mower still starts reliably and the deck and engine are in good shape, repairs are typically the better value. If you’re stacking multiple repairs at once (drive issues plus starting issues plus deck damage), replacement often wins.

• Repair is usually the better choice when:
  • The issue is a tune-up item (spark plug, air filter, oil change)
  • The blade is dull or bent and needs service
  • The self-propel drive is slipping due to a worn belt
  • The mower is otherwise in good condition (no heavy rust, no major vibration)
• Replace is usually the better choice when:
  • The engine has low compression, heavy smoking, or internal damage
  • The crankshaft is bent (often shows up as severe vibration)
  • The drive system needs multiple major parts and labor
  • The deck is cracked or badly corroded

Typical repair vs replace comparison

Situation	Typical DIY cost	Typical shop cost	Best value
Annual tune-up (oil, plug, filter)	Low	Low to moderate	Repair
Blade service (sharpen or replace)	Low	Low to moderate	Repair
Self-propel “loss of drive” from belt	Moderate	Moderate	Repair
Engine internal failure	High	High	Replace

Model-specific notes that affect the decision

Your 917378450 has clear maintenance intervals and specs in the 917378450 owner’s manual, including fuel capacity (1.6 quarts), oil capacity (20 oz), and blade bolt torque (35 to 40 ft-lbs). Keeping up with these basics reduces expensive failures and makes repair the smarter long-term choice.

If the mower is not moving or the drive is slowing, the manual’s troubleshooting points to common, repairable causes like a worn belt or drive cable. A common wear item to check is the lawn mower ground drive belt, 3/8 x 32-1/2-in 532175436.

Why it matters

A small repair that restores safe cutting and reliable starting is almost always cheaper than replacing the mower. The key is avoiding “repair stacking” where several big issues add up quickly.

Last updated: January 2026