Bought a TMEC enduro 125 with 2000 miles on the clock and a damaged big end.
Found a complete bottom end cheaply and swapped the Tmec side cases and top end on.
I decided to fit a 150 kit, matching head, better pipe and 27mm mikuni carb. After stripping the top end off and attempting to fit the big bore kit the barrel sleeve was too big for the crank case.
The bottom end is a FMI157 where the original was a 156.
So the moral is do not assume anything, measure before you spend your money.