Home Boats, Motors & Engine Parts Engine Parts Gaskets Sierra Powerhead Base Gasket For Yamaha Engine Sierra Part #18-99115 ITEM: 328377 Close Sierra Powerhead Base Gasket For Yamaha Engine Sierra Part #18-99115 ITEM: 328377 NON-MEMBER $8.99 GOOD SAM CLUB $8.54 NON-MEMBER $8.99 GOOD SAM CLUB $8.54 Ships within 5 - 6 business days Please make sure all selections are complete and a valid quantity is entered and try again. Features Reviews Q & A Features Sierra Part #18-99115Powerhead base gasketFor Yamaha engine Sierra powerhead base gasket for Yamaha engine. Sierra Part #18-99115.OEM Part Number:6G1-45113-A1 Show more Reviews Q & A