Yes, Harley-Davidson discontinued the Ironhead engine in 1985. The Ironhead engine was a type of V-twin engine produced by Harley-Davidson from 1957 to 1985. There were a few reasons for its discontinuation:
Emissions Regulations: The Ironhead engine did not meet increasingly stringent emissions regulations that were being implemented during the 1980s. As a result, Harley-Davidson needed to develop new engine designs that could meet these requirements.
Reliability Issues: The Ironhead engine had a reputation for being somewhat temperamental and requiring frequent maintenance. It had a tendency to overheat, leak oil, and suffer from other reliability issues. As Harley-Davidson aimed to improve the reliability and durability of their motorcycles, they decided to move on from the Ironhead design.
Performance and Technology: The Ironhead engine was an older design that had its roots in the 1950s. By the 1980s, advancements in engine technology allowed for better performance, efficiency, and reliability. Harley-Davidson saw the need to develop new engine platforms to stay competitive in the market.
Following the discontinuation of the Ironhead engine, Harley-Davidson introduced the Evolution engine, which debuted in 1984. The Evolution engine addressed many of the issues associated with the Ironhead and became a popular powerplant for Harley-Davidson motorcycles for several years before being replaced by the Twin Cam and subsequently the Milwaukee-Eight engines.