Just replaced my rocker box gaskets for my rear cylinder with the new James metal gasket. It went well and NO leak, however when I was took the rocker box plates apart I noticed that only one (rubber) umbrella valve was being used even though there were two oil ports in the rocker box plate that could take umbrella valves. Does anyone know if this is right? When I re -assembled the plates I replaced only the one umbrella valve...

There is only one valve used in each rocker box. They are made to fit either front or rear so the holes are there on both sides. I don't recall if they are on the intake or exhaust side, although I think they would be on the intake side as that's where the breather holes are located. (Don't quote me on that)

Cool, I don't remember which side it was on but I made damn sure that it went on the same side the old one was on. It just seemed a bit odd and wanted some feedback. I didn't want my bike to have come of the assembly line at 4:30 PM on a Friday....