Yamaha - Woodruff Key - Flywheel & Shaft Alignment - 90280-04008-00

Overview

This woodruff key is one of those small parts that keeps everything turning the way it should without much attention. It locks your flywheel or gear into the correct position so timing stays consistent under load. I’ve seen engines run rough or lose timing just because this piece was worn or slightly off. It’s simple, but it’s one of those parts you don’t want to overlook when you’re working on your motor.

Key Features

• Accurate Component Alignment – Keeps rotating parts properly indexed for correct engine timing.

• Secure Locking Fit – Prevents slipping between the shaft and connected components.

• Durable Metal Construction – Built to handle engine torque and repeated use.

• Factory-Specific Dimensions – Matches Yamaha keyways for a precise, reliable fit.

Engine & Boat Compatibility

Used across a variety of Yamaha outboards in flywheel, crankshaft, and other keyed shaft applications. Supports systems where maintaining proper alignment is critical for timing and smooth engine operation. Always confirm correct sizing and application before installation.

FAQ

Q: What are the signs of a failing woodruff key?
A: You may notice timing issues, rough running, or the engine not starting properly.

Q: Can a slightly worn key still cause problems?
A: Yes, even minor wear can affect alignment and lead to performance issues.

Q: Do I need special tools to install it?
A: Basic tools work, but you may need a puller depending on the component you’re accessing.

Q: How should it sit in the keyway?
A: It should be snug and flush, without rocking or sticking out unevenly.

Q: What’s a common mistake during installation?
A: Not seating it fully or forcing it in at an angle, which can cause early failure.

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  604-11545-00-00