Newbie here and I just purchased an 1997 RM 125 for my son and know noting about the bike or 2 strokes. Here is my issue...
At take of the bike sounds as if it were missing but picks up speed but low on torque, and does this until i get to a certain RPM, and in second if I back off it does...
Just as the title says, both our swingarm bearings are a bit tight. Have taken mine off (the 160) and will first try soaking them for a bit and cleaning them out, if that fails will be buying some more. May as well pick up both sets at the same time if they are the same size