Craftsman 917990390 tractor Parts

Craftsman riding mowers use different engines depending on the exact model and production run; for Craftsman model 917990390, the engine family is identified on the engine ID label (typically on the blower housing or valve cover) rather than by the tractor model number alone. Use that engine ID to match the correct tune-up and starting-system parts.

How to identify the exact engine on model 917990390

We recommend using the engine’s ID tag because it gives the most accurate match for carburetor, air filter, spark plug, and fuel system parts.

• Park on a flat surface, set the parking brake, and remove the key
• Lift the hood and look for an engine label on the blower housing, valve cover, or near the starter
• Write down the engine brand and the full ID (model, type, and code or spec number)
• If the label is missing, record the mower’s deck size, engine mounting pattern, and shaft orientation to help narrow it down
• Use the tractor parts list to confirm related starting and wiring components

Common engine brands you may see on Craftsman tractors

Many Craftsman front-engine tractors in the 917-series were built with engines from major small-engine makers. Your exact unit can vary, so confirm using the engine ID label.

Engine brand (common)	What the ID label usually looks like	Why it matters
Briggs & Stratton	Model / Type / Code	Tune-up parts and carburetor match to Type/Code
Kohler	Model / Spec	Spec number drives the correct parts list
Tecumseh (older units)	Model / Spec	Parts selection depends on spec and carb style

Parts that affect starting and engine operation

If you are troubleshooting a no-start or click-no-crank issue on the tractor side (not the engine internals), these model-matched parts are commonly involved:

• Lawn tractor ignition switch 532193350
• Lawn tractor starter solenoid 582042802
• Lawn tractor chassis wire harness 581023001

For step-by-step diagnosis, use our DIY video: riding lawn mower engine clicks but doesnt turn over video.

Why it matters

Ordering engine parts by “Craftsman riding mower” alone often leads to mismatches. The tractor model (917990390) identifies the chassis and deck; the engine ID label identifies the exact engine build so you get the right maintenance and fuel/ignition parts.

Last updated: February 2026

A Craftsman “6.75” walk-behind mower does not have one single model number; “6.75” is an engine power label used across multiple mowers. If you mean the common Craftsman 21-inch 6.75-hp rotary mower, the model number is typically 917377911.

How to find the correct model number on your mower

We recommend confirming the model number from the mower’s ID label so you get the right parts list.

• Look for a sticker or metal tag on the rear deck (near the bagger opening)
• Check under the seat area on some self-propelled designs (near the handle mounts)
• Look near the engine mounting area on the deck
• Write down the full model number exactly as shown (all digits)
• Use that model number when searching parts on Sears PartsDirect

Why “6.75” alone is not enough

“6.75” describes the engine rating, not the mower’s parts configuration. Two mowers with “6.75” can use different:

• Blade and mandrel-style hardware
• Drive belts and idler pulleys (self-propelled models)
• Wheels, axle parts, and height adjusters
• Ignition and safety interlock components

Quick ID checklist (walk-behind vs. tractor)

This page is for Craftsman model 917990390 (a front-engine lawn tractor), so its parts list will not match a 6.75 walk-behind mower.

What you have	Typical identifier	Parts page match?
Walk-behind mower	21-inch deck, push/self-propel	Not a match for 917990390
Riding mower/tractor	Seat, steering wheel, mower deck under chassis	Matches 917990390

Why it matters

Using the exact model number prevents ordering the wrong blade, belt, or ignition parts and saves time during repairs.

Last updated: February 2026

Craftsman model 917990390 was made across a production run rather than in one single year. The most reliable way to pinpoint the exact build year for your specific tractor is to use the serial number/date code on the ID label (typically under the seat or on the frame) and decode it to a month and year.

How to find the build year on your tractor

Look for the model and serial label, then record the full serial number exactly as shown.

• Check under the seat on the fender pan or seat deck
• Check the frame rail near the engine or rear axle area
• Wipe the label clean; dirt and oil can hide key digits
• Write down both the model (917990390) and the serial
• If the label is missing, check for a stamped frame tag nearby

Common serial number patterns (what to look for)

Many Craftsman riding mowers and tractors use a serial/date code where part of the serial indicates the manufacture date (often month and year). Once you have the serial, match it to the date format used on the label.

What you have	What it tells you	What to do next
Model number only (917990390)	Identifies the tractor family/configuration	Use the serial to get the exact year
Serial/date code present	Identifies the build month and year	Decode the date code from the label
Label missing/unreadable	Year is harder to confirm	Use parts diagrams and key components to narrow it down

Why it matters

The build year affects which deck parts, belts, steering parts, and electrical components fit your tractor. Even within the same model family, Craftsman tractors can have mid-run changes that impact fitment.

Parts that often vary by production run

If you are trying to date the tractor because you need parts, these are common “year-sensitive” items:

• PTO and deck engagement components (for example, blade clutch cable 532435111)
• Starting and key switch components (for example, ignition switch 532193350)
• Charging/starting circuit parts (for example, starter solenoid 582042802)
• Deck spindle/mandrel assemblies (for example, lawn mower mandrel assembly 587819701)

If your symptom is a no-start or clicking issue while you are identifying the tractor, we recommend following riding lawn mower engine clicks but doesnt turn over video for a quick, step-by-step diagnosis.

Last updated: February 2026