WSM Top End Kit - +0.75 mm - Honda 54-231-13 M1 YZ/YZF/WR Bolt Kit Chest pad and back compartments

Chest pad and back compartments with PE padding (Alpinestars Nucleon chest and Nucleon back inserts available as accessory upgrade

Combined with Graves’ exclusive flash tune map this system produces a solid 15+ HP in the midrange and 11+ on the top of the horsepower charts

Roll top for easy access

Increased horsepower across the entire RPM range

Bench Flashing Harness to flash your ECU outside of your side by side

WSM Top End Kit - +0.75 mm - Honda 54-231-13 M1 YZ/YZF/WR Bolt Kit Chest pad and back compartmentsTop quality piston kit Includes pistons, rings, pins, clips, needle bearings, head and base gaskets and intake and exhaust gaskets and oil filter for 4 stroke models