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 high‑performance inline‑four motorcycles

high‑performance inline‑four motorcycles

and optimal wear resistance to deliver a substantial increase along the entire power curve while maintaining strict reliability

Its open design prevents mud buildup

The levels each have three vials

accommodating most 17” laptops

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 high‑performance inline‑four motorcyclesUPGRADE 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