Athena P400485100073 304cc Big Bore Cylinder Kit (85mm Bore) - Forged Piston Performance Upgrade, Converts 250cc to 304cc, Compatible with Yamaha YZ250F & WR250F 2019-2023 Heat Gun This professional-grade cast iron adapter

This professional-grade cast iron adapter features divided port construction that preserves exhaust pulse separation for superior turbo response and performance gains

and varnish

and off-road teams

CRF 250 R(04-25)

and wear from rider boots

Athena P400485100073 304cc Big Bore Cylinder Kit (85mm Bore) - Forged Piston Performance Upgrade, Converts 250cc to 304cc, Compatible with Yamaha YZ250F & WR250F 2019-2023 Heat Gun This professional-grade cast iron adapterUPGRADE YOUR DIRT BIKE TO THE NEXT LEVEL OF PERFORMANCE Extract massive power, aggressive low end torque, and unmatched acceleration from your 250cc four stroke engine with the Athena Big Bore Cylinder Kit (Part No. P400485100073), a premium race proven package engineered in Italy to seamlessly convert your factory setup into a high revving, high output 304cc powerhouse. Entirely cast from high grade aluminum and treated with a specialized Motor