Sierra 18-6455 AlternatorSierra replacement alternator for Mercury Outboards. Sierra aftermarket engine parts are manufactured to meet or exceed OEM requirements. 5S/I 50 amp; Fits: 1.5L and 3.0LFor: 200 DFI, 200 DFI/DTS, 225 EFI, Sea Pro, 225 DFI/DTS, 250 EFIInterchangeable with: Arco; 20850; Mallory; 9-19201; 9-19204; Mercury Marine; 828506; 875286A1; 875286T; 881247A1; 8M0064020; Mercury Sport Jet; 881247A1;