ITEM NAME:Cylinder Head Base Gasket Fit for Yamaha 9.9 15 18hp 2-Stroke Outboard Engine Description: Replaces Number: 63V-11181-A1-00 Engine Position: Outboard Engine: for 2-Stroke 9.9hp 15hp 18hp Replacement parts are available in stock Fitment: for Yamaha 2-Stroke 9.9hp 15hp 18hp Outboard Engine Specification: Center Hole Diameter: Approx. 58mm / 2.28inch Package Includes: 1 Piece Cylinder Head Gasket SKU: DMO0000392367007652.Engine: for 2-Stroke 9.9hp 15hp 18hp. Engine Position: Outboard. 1 Piece Cylinder Head Gasket.