Yamaha - Woodruff Key - Flywheel & Shaft Alignment - 90280-04M08-00

Overview

This woodruff key is one of those small parts that keeps everything in sync without much attention. It locks your flywheel or gear in place so timing stays right where it should be. I’ve seen engines run rough or lose timing just because this piece was slightly worn or out of place. It’s simple, but it’s a critical part of keeping your motor running smooth.

Key Features

• Precise Timing Alignment – Keeps rotating components properly indexed for consistent engine performance.

• Secure Shaft Engagement – Prevents slipping between the shaft and connected parts under load.

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

• Factory-Exact Fit – Matches Yamaha keyway dimensions for proper seating and reliability.

Engine & Boat Compatibility

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

FAQ

Q: What are the signs of a worn woodruff key?
A: You may notice timing issues, rough running, or difficulty starting the engine.

Q: Can I reuse a woodruff key during reassembly?
A: It’s not recommended—replacing it helps avoid future alignment issues.

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

Q: How should the key fit in the shaft?
A: It should sit snug and flush without rocking or sticking out unevenly.

Q: What causes these keys to fail?
A: Improper torque, sudden impact, or slipping components are the most common causes.