Yamaha - Woodruff Key - Flywheel & Shaft Alignment - 90280-03047-00

Overview

This woodruff key is a small part that plays a big role in keeping your engine running right. It holds critical components in position so timing stays locked in every time you turn the key. I’ve come across engines with strange performance issues that traced back to a worn or partially sheared key like this. It’s simple, but if it’s not right, nothing else lines up the way it should.

Key Features

• Precise Component Indexing – Keeps flywheel and shaft aligned for proper engine timing.

• Secure Anti-Slip Fit – Prevents movement between mating parts under load.

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

• Yamaha-Specific Sizing – Designed to fit factory keyways without modification.

Engine & Boat Compatibility

Commonly used across Yamaha outboards in flywheel, crankshaft, and other keyed shaft applications. Supports systems where accurate alignment is critical for timing and smooth operation. Always confirm size and application before installation.

FAQ

Q: What are signs this woodruff key is damaged?
A: You may notice timing issues, loss of power, or the engine not starting properly.

Q: Can I reuse a woodruff key if it looks okay?
A: It’s best to replace it—small wear or deformation can cause bigger problems later.

Q: Does this require any adjustment after installation?
A: No, just make sure it’s seated properly and aligned before reassembly.

Q: How do I know it’s installed correctly?
A: It should sit snug in the keyway and allow the component to slide on without resistance.

Q: What causes a woodruff key to shear?
A: Usually sudden load, improper torque, or components slipping out of alignment.