Yamaha - Woodruff Key Flywheel & Shaft Alignment 90280-05025-00. Overview. This woodruff key is one of those parts you don't give much thought to until something slips out of sync. It's what keeps critical components locked in position so your engine timing stays right where it should be. I've run into plenty of cases where a worn key caused rough running or no start at all. It's a simple piece, but it carries a lot of responsibility every time the engine turns.. Key Features. Accurate Shaft Alignment - Keeps rotating components properly indexed for consistent timing.. Slip-Resistant Fit - Prevents movement between mating parts under load.. High-Strength Material - Built to handle engine torque and repeated use.. OEM-Spec Dimensions - Matches Yamaha sizing for a precise and secure fit.. Engine & Boat Compatibility. Used across a wide range of Yamaha outboards in applications involving flywheels, crankshafts, and other keyed shaft components. Essential for maintaining proper alignment a