The offensive ring is approx .4mm smaller in width than the old ring. But I don’t know what the comparative measurement is/was pre install as I didn’t measure the width before so I don’t know how much that indicates.
both cylinders measure at 76.5mm(at the top, with calipers) and ring sizing behaviour is the same in both cylinders for all rings/pistons which says to me the cylinders are the same.
what I’m left with is possible options of
-my ball hone left too rough cylinder
-possibly excess grit left from improper cleaning
-excess fuel from stuck choke washing pre-assembly oil from walls
-possilbly missed the ring locate pin causing ring to spin and wear (it’s tough but I can get the cylinder back on, during diassembly the gap was close to the pin but I can’t say with 100% certainty)
-uncertainty of exact roundness of cylinder
Some or all of these caused the rings to wear excessively fast causing low compression on the mag side.
I am still stuck with how was this even possible??? The only thing that I can think of is if there were high peaks that worn down, but again is this even possible??? It isn't like you are adding material, but rather removing!
I echo skipower
in post #7 that something else is going on. How about measuring the width of the ring? To have worn that much it must be a lot more narrow, yet it appears the same in the picture. Since the old ring still fits fine, is one bore smaller? This reminds me of the games to spot the differences in two pictures lol