Quick look at the specs and some guesswork:
MT125 and R125 share all chassi dimensions, both fitted with 100/80 + 130/70 tires, have 11.5 L tank, fully wet 140 kg and 142 kg, both in ABS version.
R3 has 321cc 42hp 180° crank twin, fitted with 110/70 + 140/70 tires, has 14 L tank, fully wet 169 kg in ABS version.
The MT3 ABS sharing engine/chassi with R3 would then be 167 kg fully wet.
The MT125 is 25 kg lighter than the MT3 (taking feul tank into the equation).
The MT3 is 15 kg lighter than the MT07.