Yamaha - Woodruff Key Flywheel & Shaft Alignment 90280-05033-00. Overview. This little woodruff key might not look like much, but it's doing serious work behind the scenes. It locks components like the flywheel or gear into proper alignment so everything spins exactly how it should. I've seen engines run rough or not at all just because this piece was worn or missing. It's one of those parts you don't skip if you want your motor running smooth and reliable.. Key Features. Precision Alignment Fit - Keeps rotating components properly indexed on the shaft.. Secure Component Locking - Prevents slipping between mating parts under load.. Hardened Metal Construction - Built to handle torque and long-term engine use.. Exact Yamaha Specification - Matches factory dimensions for proper seating and performance.. Engine & Boat Compatibility. Used across a wide range of Yamaha outboards in applications involving flywheels, crankshafts, and other rotating assemblies. Common in setups where precise a