John, yes, I'm thinking still it's the poor hone job.Both pistons have the same slight wear patterns and these bikes don't use offset piston pins, so the pistons aren't installed backwards.I have a new bore gauge coming so I can check it out for myself.If I have to push the limits on the piston clearance to get a clean hone job, it'll be ok according to my past experience with British bikes.I'm also going to try Deves rings, they are steel alloy, not cast, supposed to be superior to even Moly rings, especially for demanding conditions.
