4 speed, shaft diameter 14 of the right side and 17mm on the left side.
total length 131.65mm
2nd gear 25th (previous years was 26th)
Assignement :
Lifan 125 type 1P52FMI the true one that permit to start on any gear (since 2013)
Lifan 140 type 1P55FMJ (since 2013)
Lifan 150 type HS1P56YMJ (since 2013)
 
Attention you can not replace that shaft with the older primary shaft
You need to change both sets shaft as it is compatible on an old engine