Athena Piston Kit - 53.94 mm - YZ125 - S4F05400011A

Two-stroke pistons are made from 4032 silicium. Four-stroke pistons are made from 2618 silicium - the same material used to produce Formula 1 pistons. Both include 3% copper in materials for better heat resistance. All pistons are forged using a precision heat-treatment process that allows for production tolerances of just .005mm. Forged piston tooling allows for the lightest available product. Kit includes antiwear coated piston, rings, pin and circlips.