Quote Originally Posted by Fastjeff57 View Post
They are .015 oversize cut to fit a standard bore. Genuine Merc rings. All 6 rings wore the same (actually 5--one of them broke on me). I assume the rings wore, not the bore, but I'll re-measure.

So, this is NOT normal after such minor running? It happened twice with the engine (early Merc triple).

Jeff

PS: Thanks for the inputs.
Hi
Others may disagree but I would say that as you are using 0.015 oversize rings and filing the ring gap that the wear is due to the fact that not all of the outer surface of the rings are touching the bore which would result in the rings wearing excessively where they touch and slight wear where they do not touch. You are trying to fit a large radius into a smaller radius which leaves a gap where they don not touch. I would suggest that you measure the ring depth all the way around and I would bet that it is not uniform but would be consistent with the other rings. I would try to get the standard rings. If you have a spare 0.015 oversize ring I would suggest that you drop it into the bore and run a feller gauge around the circumference to see if there is any gap.