Hey everyone. I have a 2001 660 that will jerk right or left with the terrain. It starts tracking and starts pulling. I also have a 2005 400EX that rides smooth as silk through the same trails. What can I do to fix this problem. It is very tiring riding the 660. Can the problem be caused by the front shocks. I do have a set of yfz450 for the front I was thinking of installing, but If I cant fix the problem I will install them on the 400EX instead. I am just getting beat to hell on the 660.