Aftermarket part: Brand ITACOFor Yamaha part number: 6B4-11111-00-1S 2 stroke (IMPT: Check OEM part number before purchase!!!)For Yamaha Outboard Models some (Year 2003 - 2015 later): 9.9HP, 15HP M F S E series 2 strokeCylinder Head AssyBoat Motor for Outboard Engine..