New Norton owner here. In the process of restoring a 26,000 mile '74 MkIIA. The shop manual states that removing the carbon ring at the top of the cylinder head and the piston will increase oil consumption. If so, I can't quite fathom how. New engines don't have this carbon ring, so do they use more oil? Not in my experience. This "advice" seem rather unfounded to me, so perhaps those of you experienced with these engines can help a brother out.
BTW, I've already got the head off and I intend to completely rebuild the engine. May not need a rebore and new pistons, but I'm sure as hell going to replace the rings, so all the carbon is going "buh-bye" one way or another.
BTW, I've already got the head off and I intend to completely rebuild the engine. May not need a rebore and new pistons, but I'm sure as hell going to replace the rings, so all the carbon is going "buh-bye" one way or another.