I just tore down my bike and removed the head so I can send it out to have the intakes replaced and the seats cut. I wasn't going to take the cylinder off at first but then decided to check it out to make sure everything was good to go. Turns out everything is not good to go and I am glad I checked. The nikasil on the back (intake) side of the cylinder has flaked off and it caused the piston to get scuffed and generally gnared up. The skirt is also cracked in the webbing on the same side. Now that would be no big deal, things like this happen. Heres where the big deal comes in though, this isn't the first time this has happened. Shortly after purchasing my bike the same thing happened in the same spot and it took out the oem bore and piston. I noted that the nikasil looks extremely thin compared to other coated cylinders I have seen. But I figured it was just one of those things that happen and chocked it up to a bad cylinder. To fix the problem I purchased an oem cylinder and got a wiseco 13.5:1 high compression piston, slapped it in and called it a day. I have had maybe 30 hours on the bike between then and now. My first thought was maybe its piston slap because I haven't had good success with wiesco and against my better judgment I went with them because I am a parts unlimited dealer and got it cheap. The piston seems pretty tight in the bore and I would believe that the opposite side of the bore would become equally screwed. I had my friend come over who has an extremely keen eye for this sort of stuff noted that the bore appears to have high and low spots, and that combined with extremely thin coating caused the flaking which led to the death of the piston. The only thing is I don't have a dial to verify the bores continuity. So basically I am thinking about getting an aftermarket cylinder from cylinder works (I get them cheap because I am a dealer). I felt my ideal action would be to send the cylinder out to la sleeve to have an awesome liner put in, but they don't have the liner in stock and their turn around is quite slow, and I am in a time pinch at the moment. Also I was thinking to send the cylinder out to lukes racing. I have used them before when I had a YZ134 and I had a ring break and get jammed between the cylinder and the piston and the coating didn't have so much as a scratch on it. They do great work but aren't accepting orders until the summer time for some reason, so that is out. I will break down what I'm asking of you guys. 1. What other things could lead to this type of failure? 2. What are your thoughts on the oem cylinders 3. Is this a common problem? If so is there a solution? 4. Has anyone had any experience with cylinder works? 5. What piston do you guys recommend? I'm quite certain I will be going with oem 6. How much do you love Entenmann's chocolate donuts? I appreciate your forthcoming input guys. Pics to follow.