So I got an extra cylinder for my kx 250 from that auction site... just recieved it today and it's sleeved! I still need to make sure it is in spec, but I was always under the assumption that plated was much better, so I was a bit disappointed. I did some searching and found this in a transworld motocross article (quote from LA Sleeve): http://www.transworldmotocross.com/mx/features/article/0,13190,598355,00.html Mark let us in on some of the advantages of a sleeved cylinder vs. Nikasil-plated cylinders. "What's important about sleeves, is that they hold more compression than a Nikasil cylinder, because of the cross-hatches and the way the sleeve dissipates heat faster. The dirt trackers and flat trackers have been buying sleeves from us for the last 15-25 years—it's their secret. A lot of the Supermoto guys are starting to buy sleeves from us, because they're realizing they're getting 3-4 more horsepower with a sleeve than Nikasil." "The only reason the factories are running Nikasil is because it's more cost-effective in production. They don't have to have it put in, The cylinder can go in and boom, it's ready. A sleeve has to be dropped in, and matched. The Nikasil was just another way to cut cost with the factories, and it is lighter than the sleeves." What are some of the other benefits? According to Mark, "When a customer's engine seizes, there may be a scratch that requires them to get a whole new Nikasil plating, which may cost about $300. If they have it sleeved, the next time it scratches or scores the cylinder, they may only need to hone it, or get a bore job…which runs more in the range of $30 to $60. It's way cheaper, and you can bore it up to four times. It's more cost-effective for the rider." Interresting.... Never heard the whole horsepower bit before and it seems really excessive so I'm not sure I believe that one... Assuming it's in good shape, will the sleeve work well (I'm mostly concerned with reliablility)? Anything I have to do different besides the honing (I don't hone my plated cylinders, just deglaze)? Also, the last set of rings I got from wiseco said they were not to be used in a chromed cylinder, are the correct rings easy to get a hold of? If anyone is wondering, I got the cylinder so I could have a stock replacement for my 310, as it is becoming hard (and expensive) to find pistons.