I finally collected all the parts to freshen up my 2000 XR650R. This was all brought about by a broken timing chain, while riding home from work during rush hour traffic (real fun). Anyways, my question at the moment is about the rings. One appears to be a cast iron ring with an "R" stamped on it. The other looks a moly filled ring with a "RN" printed on it. So, which one is the top ring? The manual says to use the ring with the "R" on top. So, does the cast iron ring go on top? This is the way it came apart. The reason for my concern is that the BRP previously had quite an appetite for oil! On an automobile engine, the moly filled ring goes on top with the cast iron ring in the second position. Ted K.