One of the difficulties of making a forged piston is that the high-strength aluminum alloy is hard to process. That is why it is necessary to maintain exactly the right temperature and mold pressure during the forging process. To solve this problem, Yamaha has developed an exclusive “Controlled Forging Technology” that optimizes the relationship between pressure and temperature. One of the characteristics of a forged piston is its shorter skirt compared to a cast piston.