I plan on doing a top end job on my 05 yz250 with the wiseco piston kit. It is not blown up or anything but I bought it used and I'm pretty damn sure its the stock piston lol. Y'all tell me what I need to know in order to get his done correctly because I have never done this and I don't plan on screwing it up. Any advise helps, thanks. p.s. what does it mean to measure the clearance? and how do you do it?