Sheesh now that dont make sense. the 185 uses a 64mm . most 125s are 61, i think even the honda 750-4 uses a 61 i think.
why would you put those numbers on if it wasnt a size?
im sure Ive read someplace (wossner or wiseco) about the size being written that way in two parts. Good luck and I will check on the answer as Im intrigued.