Athena P400485100073 304cc Big Bore Cylinder Kit (85mm Bore) - Forged Piston Performance Upgrade, Converts 250cc to 304cc, Compatible with Yamaha YZ250F & WR250F 2019-2023 Expansion Tool X2 LXT technology delivers more

X2 LXT technology delivers more power

or fine-tuning your CRM250 for vintage racing

YFM 700 Grizzly(07-16)

Engineered for reliability

and confident cornering

Athena P400485100073 304cc Big Bore Cylinder Kit (85mm Bore) - Forged Piston Performance Upgrade, Converts 250cc to 304cc, Compatible with Yamaha YZ250F & WR250F 2019-2023 Expansion Tool X2 LXT technology delivers moreUPGRADE 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