Forged Aluminum Piston (Alumite-treated)

Though difficult to manufacture, Yamaha has mastered forging large-diameter aluminum pistons with high levels of precision.

Forged Aluminum Piston (Alumite-treated)

Because of the large piece of aluminum used, an extremely high amount of pressing force and forming load is needed to forge large-diameter pistons. Yamaha's high-force presses are capable of meeting very precise forging requirements, enabling mass production of these pistons. Furthermore, an alumite treatment prevents adhesion and impact wear around the piston ring grooves.