Install a big bore kit for optimum power in your dirt bike to tackle the roughest terrain, gnarliest hills and get an edge on the competition. Find a wide range of dirt bike big bore kits at MotoSport that fit many makes, models and years including CRF125f and other 125cc pit bikes. When deciding on a big bore kit for your ride, use the Fitment Expert on the product page to ensure the right big bore kit for your dirt bike. Most big bore kits include a cylinder, piston, ring(s), pin, clips and to p-end big bore gasket kit. If you want help finding the right big bore for your dirt bike please call 503-783-5645 to talk to a gearhead who can answer questions and point you in the right direction so you can make an informed buying purchase.