A well-secured propeller isn't just about performance-it's about longevity, efficiency, and smooth operation on the water. The Sierra 18-4274 Prop Spacer is designed to ensure a tight, stable fit between your Yamaha outboard's propeller and shaft, reducing vibration, preventing unnecessary wear, and enhancing overall propulsion. Built for durability, this spacer is a simple but essential component that keeps your engine running at peak efficiency.. Engineered for a Reliable, Smooth Ride. Precision Fit - Keeps the propeller securely in place, minimizing unwanted movement and stress on drivetrain components.. High-Quality Marine Construction - Built to handle corrosive saltwater and freshwater conditions, ensuring long-term durability.. Optimized Performance - Helps maintain proper propeller alignment, improving thrust, fuel efficiency, and handling.. A Small Component with Big Benefits. Compatible with a wide range of Yamaha outboards (115 HP - 300 HP models), this spacer plays a crucia