
PROX Forged Piston designed for motocross and demanding engine preparations. Machined from a specific aluminum alloy, this forged piston reduces friction and aims for enhanced longevity without compromising reliability. Intended for the listed 450 cc engines, it maintains a standard compression geometry for optimal compatibility with stock configurations.
This piston is designed for riders seeking a reinforced stock part for enduro and motocross: acceleration response, thermal resistance, and resistance to typical off-road stresses. The oversize "A" must correspond to the appropriate bore — check the cylinder diameter before installation.
Common applications (examples): YAMAHA YZ 450 F (2026), FANTIC XXF 450 (2026), YAMAHA WR 450 F (2026). For safe installation and compliant segment clearances, follow the manufacturer's recommendations or consult your tuner/mechanic.