Hello dear community, I hope you can help me. I recently brought a Rex Rs 450 back to run after 2 years. Now it runs really ok, but when it gets warm the rear wheel jerks in the stand as well as when starting up… what’s that?? Besides, it jumps cold with the E-starter very hard, sometimes even when it is warm… I mean with jerking that he gives gas for a short while and lets go. The whole thing happens so quickly in a row that the whole scooter jerks. But if I Gas he takes it well and accelerates clean through without any problems. So only in stand and when starting up… Does the jerking come from the clutch, from the CDI, from the weights??? I have no idea! Please help me!