Originally Posted by
ATC200X4716
That is correct most sleeves are cast in place from the factory and then finish bored/honed so there is no guarantee the bore and the OD of the sleeve are perfectly concentric, so if you had to machine out the sleeve you may and up with a sliver of iron on one side and no sleeve on the other. The new sleeves are usually put in with several thousandths press fit depending on size and the cylinder is heated in an oven and sleeve goes in the freezer, and then drop them together. 2 strokes are tough cause you have about 2 seconds for it to drop together and rotate to line up the ports before it freezes in place. I usually put the sleeve in an upside down lathe chuck on the bench, and drop the cylinder down on the sleeve while looking at the exhaust port/bridge to make sure it is lined up.