The amount of reserve is determined by the height of the brass stand pipe inside the filter. You could compare the CBR 600 to the Valkyrie stand pipe height. I don't have a Valkyrie petcock other than the leaking one on the bike. Before I replace it I will be comparing the 2.
This I already knew, was hoping you might have compared the two which would be an indicator. Sorry I didn’t clarify.
Rams