There are a lot of different opinions on the "right" way to hone a cylinder. There's no "one size fits all." The requirements for modern high performance water-cooled engines are not the same as for our antiquated air-cooled iron cylinder bikes. Also depends a lot on the ring materials. In general, the coarser grits provide a faster break-in, good for a race engine, but also faster ring wear. The finer grits require a more careful break-in, but are reputed to give slower ring wear. The usual recommendation for old style iron rings with a chrome plated top ring (like most of the available Norton rings), is to finish with a fine stone (240 or 280 grit, sometimes 320 grit). The more modern ring finishes, like moly or ceramic, require much smoother cylinder finishes, but take almost no break-in time. You don't usually see them offered for Nortons.
FWIW, I usually finish a rebore with a conventional Sunnen style hone with 280 grit stones, and then run a 320 grit silicon carbide Flex-hone (ball hone) through for the final finish. Seems to work pretty well. That's with conventional iron rings with chrome top ring. In the rare occasion I use moly filled rings, I finish with a 500 grit conventional hone and then run a soft brush style plateau hone through for the final finish. If you're just looking to put a better finish on a cylinder for new rings, with no re-sizing, the 240 grit Flex-hone should work fine.
Ken
