Piston Kit - 101.95 mm - Yamaha The piston is heat-treated with aT-5 hardening and tempering cycle, The piston skirt is treated with a Molybdenum Disulphite coating for a faster break-in time and increased piston life, Forged replica piston is a forged OE , Replica piston and all rings are OEM , Piston kit includes piston, ring, wrist pin and circlips