I wondering what the ID numbers on the 650sx cylinders are? Not the letter "A", "B", and so on. What are the numbers like the ones on the 750 cylinders? Like a "No stamp, "22" and so on?
Mine have the "A" stock bore, but it also has "11/1", "E-1, and D-(circle 3)? I'm pretty sure the 11/1 is a...