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Yamaha

Yamaha 90280-03017-00 Genuine Woodruff Key

★★★★★3.6 (4 reviews)

Stop flywheel timing slippage cold — Yamaha OEM part 90280-03017-00 is the exact-spec Woodruff Key your Yamaha powersports engine needs.

$10.95*
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*Price sourced from Amazon.com. Last updated:Jul 14, 2026.Price and availability are subject to change.

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Overview

The Yamaha 90280-03017-00 Woodruff Key is a genuine OEM replacement for one of the most mechanically critical small components in a Yamaha powersports engine. The Woodruff Key seats in a matching slot between the crankshaft taper and flywheel hub, locking them in precise rotational alignment. That alignment determines ignition timing — get it wrong by even a few degrees and the engine will run poorly or not at all. Yamaha manufactures this key to exact specifications for the crankshaft slot geometry and shear strength profile of the specific models it serves, ensuring that the flywheel seats and torques down exactly as engineered.

This part becomes necessary after any event that stresses the flywheel-to-crank interface — a hard crash, a hydrolocked or seized start attempt, or simply discovering a failed key during routine maintenance. Diagnosis is straightforward: a sheared or deformed key produces timing-related symptoms like hard starting, misfires, backfiring, or sudden power loss. Replacement is a precision job that requires proper flywheel removal tooling, but the repair itself is uncomplicated once the flywheel is off. Because this is a genuine Yamaha part rather than an aftermarket equivalent, mechanics and owners can install it with confidence that tolerances are correct and the key will perform exactly as the original did.

Key Features

Genuine ‎Yamaha part that fits your specific vehicle

Woodruff Key

Part Number: 90280-03017-00

Manufactured to meet specifications for fit, form, and function

Specifications

Part Number
90280-03017-00
Part Type
Woodruff Key
Brand
Yamaha
Authenticity
Genuine OEM Yamaha part
Application
Flywheel-to-crankshaft alignment, ignition timing

Pros & Cons

👍 Pros

  • Genuine OEM Yamaha manufacturing ensures dimensional accuracy — no guessing on key width, height, or radius fit.
  • Exact crankshaft-to-flywheel alignment is restored, which directly determines ignition timing precision.
  • Inexpensive insurance against the cascading consequences of running with a damaged or missing key.
  • OEM sourcing means correct metallurgical spec for shear strength — engineered to fail predictably under impact rather than transmit destructive force to the crankshaft.
  • Simple single-piece component with no break-in or adjustment required after correct installation.

👎 Cons

  • Fitment is vehicle-specific — part number 90280-03017-00 will not fit every Yamaha model, requiring parts catalog verification before purchase.
  • Flywheel removal requires a model-appropriate puller tool that may need to be rented or purchased separately.
  • Sold as a single key only — no gaskets or related hardware included, which may also need replacement depending on what caused the original key failure.
  • The root cause of key failure (impact, seizure, improper torque) must be identified and corrected, or the replacement key will fail again.

Frequently Asked Questions

The Woodruff Key is a small crescent-shaped metal key that locks the flywheel to the crankshaft in precise rotational alignment — critical for ignition timing. It needs replacement when it shears or deforms, which typically happens after an impact, a seized starter event, or a crash that stresses the flywheel hub.
This is a Yamaha-specific OEM part number. Fitment is confirmed by cross-referencing your vehicle's parts diagram using part number 90280-03017-00. Yamaha uses this part across multiple powersports platforms, so verify against your specific model's parts catalog before ordering.
This is a genuine OEM Yamaha part — not an aftermarket reproduction. It is manufactured to Yamaha's exact dimensional specifications for fit, form, and function.
Woodruff Key replacement requires flywheel removal, which typically needs a flywheel puller specific to your Yamaha model. Once the flywheel is off, key replacement itself is straightforward. It's a manageable job for a mechanically experienced owner with the right puller tool, but it's not a roadside fix.
A sheared key allows the flywheel to shift timing position relative to the crankshaft. At minimum, you'll experience hard starting, misfires, and power loss. In worst-case scenarios, severely advanced or retarded timing can cause engine damage. Replace it before attempting to restart.

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