Son bent a valve on a 660, ran it low on oil. I checked all the piston and cylinder clearances and they are all perfectly in spec. Ordered new stock rings from the dealer, no instruction as to which is the top one. Anyone know if its the dark coated ring with the letter on it or the plain non marked ring. No discernible difference in bevels or other giveaways between the two. Even called several dealers and nobody knows the order. Thanks for any help.