i had an 02 cr125 and kept it stock except for a vertex piston, v-force and fmf fatty pipe, then i got an 05 and had it bored to a 139 by Erik, then added v-force and fmf fatty pipe. why is it that my 02 spanks the 05? it is sooo much more potent off bottom and pulls to the moon in mid, to where the 05 139--ehhh--its ok. it seems to be extremely linear through the whole power band and doesnt really pull my arms out of their sockets like the 02 does. :think: