I sent my 05 RM125 motor out to ProCircirt for head and cylinder modifications. When the motor came back I immediately noticed I hade a problem shifting. The shift lever felt like it was welded in place when I was trying to up shift power. When I’m riding under less condition (less RPM's) the bike will shift fine through all gears. I have changed the clutches several times, inspected the pawls, changed to a Hinson basket, increase spring rate, and tried several oil weights, all unsuccessful. I can’t believe I'm the only one experiencing this problem. I seem to believe this has something to do with the change in the motor since it was fine prior to the modifications. Any suggestions???