I have an 05 YFZ450R Quad and the motor needs rebuilt. It spun the Crank bearings. Dont have time to do it and really have know Idea how. Head and Jug are off. I need someone that knows(really knows not just thinks they know) to rebuild it. Not sure if I should go aftermarket big bore or just go stock. Stock parts are more exspensive than aftermarket (thats a first).