Shop for Replacement Mercury Outboard Parts Mercury Mariner plant is a leading manufacturer of Mercury outboard parts, so that boaters can rely on dependable performance from their Mercury outboards. Today, in place of the barns where cows once resided, Mercury Outboard engines now become reality. Carl soon changed careers, switching from a dairy farmer to manufacturing marine outboard engines. His initial order was for 16,000 outboards. It soon became clear to boaters that his products were superior. During the early 1950s, Carl Kiekaefer, a young engineer, began his career reselling refurbished outboards as a means to support his inventions. It wasn't until after WWII that recreational boating became popular in the United States.