Hi, I have a RM 125 1998, i reacently rebuil the top end with a new piston, rings and with gaskets. The bike starts with the first kik. But it feels like something is holding it when is on six gear. The front sprocket is 12 and the rear is 51 and i also adjust the power valve one and one half turn tension from zero tension at all. Let me know if you have some input to this problem. Thanks.