when did yamaha start making 4 stroke outboard motors
Outboard motor Although four stroke outboards have been sold since the late 1920s, particularly Roness and Sharland, in 1962 Homelite introduced a commercially viable four cycle outboard a 55-horsepower motor, based on the 4 cylinder Crosley automobile engine. This was called the Bearcat that was later purchased by Fischer-Pierce who are the makers of Boston Whaler for use in their boats because of their technical superiority and efficiency over two strokes. In 1964, Honda Motor Co. introduced its first four-stroke powerhead.[15] In 1984, Yamaha introduced their first four-stroke powerhead. These motors were only available in the smaller horsepower range. In 1990 Honda released 35 hp and 45 hp four-stroke models. They continued to lead in the development of four-stroke engines throughout the 1990s as US and European exhaust emissions regulations such as CARB (California Air Resources Board) led to the proliferation of four-stroke outboards. At first, North American manufacturers such as Mercury and OMC used engine technology from Japanese manufacturers such as Yamaha and Suzuki until they were able to develop their own four-stroke engine. The inherent advantages of four-stroke motors included: lower pollution (especially oil in the water), noise reduction, increase fuel economy, increased low end torque, and smoother operation.
Harley-Davidson Evolution engine The Evolution engine (popularly known as Evo) is an air-cooled, 45-degree, V-twin engine manufactured from 1984 by Harley-Davidson for the company's motorcycles. It was made in the 1,340 cc (82 cu in) displacement for Harley-Davidson Big V-twins bikes, replacing the Shovelhead engine until 2000 when the last EVO was placed in a production factory custom FXR4 (FXR2 and FXR3 were the first CVOs). In 1999, it was replaced by the Harley-Davidson Twin Cam 88 in the Touring and Dyna model and in 2000 in the Softail models. Also available in the Sportster model beginning in 1986, it was made in the 1,100 cc (67 cu in) displacement until 1988 and is still made in the 883 cc (53.9 cu in) and 1,200 cc (73 cu in) [1] displacements for the Harley-Davidson Sportster, replacing the ironhead Sportster engine.