Just curious, how using the g5 cylinder ended up working out? I also have a ke100 with an aluminum cylinder that is scored up pretty badly. I looked into getting it re-nikasil coated by powerseal usa, which is local to me, but it costs ~$200, way more than i initially paid for the bike. I have a g5 parts engine with a cast iron cylinder, but it sits about ~0.25" lower than the aluminum cylinder, causing the piston to interfere with the head and ports partially covered when at BDC. Any info from your research would be appreciated!