55 amp alternator 817119A4 is for 4-cylinder MerCruiser sterndrive or inboard engines made by General Motors from 1982 through 2016. It is also for V6 and V8 MerCruiser sterndrive or inboard engines made by General Motors 1982 through 1996. See your service manual for replacement directions. Easy to change out your non-functioning alternator with common shop tools. The Quicksilver brand is the leader in delivering uncompromising engine oils, parts and accessories to the marine industry for over 65 years. Quicksilver is the premier supplier of Mercury Marine original Equipment replacement engine parts, oils, and accessories, but also works to serve all original Equipment brands in the marine and powersports industries. It has earned a loyal following by providing the highest quality products that are tested through some of the most rigorous environments and testing procedures. No aftermarket company comes close to the level of research and design as Quicksilver; buying Quicksilver is buying performance, protection and peace of mind.