So i ust bought a 2007 yfz 450 from a guy who said he got the top end rebuilt. I took the engine out cause some of the gaskets were leaking in the bottom end so i had to replace those. I figured i mine as well just take the top end apart just to check it. The guy obviusly reused the piston which may not be a problem, and all the rings looked fine, im just not sure if their new or not. Anyways, how do you suggest i break in this top end. I aready put a new oi filter and mineral oi in the engine. I also did a coolant flush. i know theres lots of forums out there already about this, but everybody contradicts each other. I agree with running mineral oi because it allows the rings to seat better, just wandering about driving it, giv er hell, or take it easy?