You know I have a 04 cr125 2mm stroker crank 1mm up 1mm down, and a 2mm over borre that I didn,t want. With the stroker crank, it comes on the pipe slower. But when it starts pulling there,s a big torque boost over a wide spread, with 2k more over rev. I prefer a standard borre 54mm, because of the weight of the 56mm GP piston, it makes the bike feel heavier. But the extra hp and torque is awesome, 20 lb plus torque, 40 + hp. Pc pipe and pc regular silencer, will try a pc shorty to get it quicker and less backpressure= heat, vforce gonna install a rad valve to get quicker off corners, older model icat, carb borred to 40mm, leaded race fuel. I,m trying to make it quicker, so I have an advantage against 450,s in the tight technical stuff. Ps stroker cranks have a different sound to them, kind of like a whirling sound. When ya fire it up, some riders know right away, they say ah ya got it stroked then there,s talk look out for the stroked cr125. I think everybody knows a stroked 125 , is sick they sound different when on the pipe pulling. Real barky and torqey sounden, but still revs higher than a 125.