Selling a Red Moto Big Bore 300 CC kit for a 2018-2023 Honda CRF250R or RX. Has about 15 hours on the cylinder and piston by a 51 year old trail rider. Comes with ECU as well already programmed by Red Moto. Comes with valves and springs too. Here is a link to Red Motos Website: https://www.redmotousa.com/product-page/crf300-engine-kit Note that there price does not include an ECU, only to reprogram your stock one. Excellent Condition. Thanks for looking.