Marine engines are mostly Yanmars in newer boats. But in the brokerage market, plenty of yachts have Perkins, Westerbekes, Universals, or Volvos.
Universal Motor Corp., a US company headquarted in Oskosh, WI, was the largest producer of marine engines. In 1948, Universal introduced a gasoline engine called the Atomic 4 which became popular. They were unrivaled until the 1970’s when diesel powered engines became more popular. Boaters prefered diesels which did not have the dangerous fumes and high volatility of gas. Universal would have trouble adjusting. According to Universal, in 1989 the market share for diesel auxiliaries was 45% Yanmar, 42% Universal, and 18% Volvo/Westerbeke/Perkins. In 1990, Universal sold to Westerbeke.
In 1959, a British industrial company Perkins introduced the 4-99, a diesel engine for general applications especially power tractors. Perkins, not realizing the marine applications of the 4-99, sold the US import rights to Westerbeke. By the mid-1960’s, Perkins took back control and became a fierce competitor offering the Perkins 4-99 for marine use. In 1997, Caterpillar bought Perkins.
Westerbeke, the “Poor man’s Perkins,” does not have a good reputation. They did well for awhile until Perkins introduced the engine themselves. Then, Westerbeke combined blocks and parts of other manufacturers to ween of their dependency on Perkins. Some of these engines are the kiss of death for a boat like in the Hylas 44. Westerbeke produced better received generators. In 1990, they bought Universal mixing in their engine parts.
Yanmar, a Japanese manufacturer, dominates the marine diesel market. In the 1970’s, Yanmar diesels quickly took market share from Universal gas engines. In the 1980’s, boat building outsourced east to Taiwan, closer to the Japanese Yanmar. The 4J series is the most common engine you see today. Virtually all yachts built after 1990 have a Yanmar, and owners have repowered many 1980’s boats with Yanmars. New yachts almost all have a Yanmar engine standard.
Volvo is a Swedish car manufacturer which always have produced marine engines both gas and diesel. Penta is the subsidary that makes the Volvo engines since merging in 1935. Volvo has been and still is a steady player with a smaller market share.