Steady disk on China scooter broken

Good morning together dear community. Maybe you can help me. I drive a problem-loaded China scooter. While I have been lying down several times with torn drive belts and I have now apparently got this problem under control after the third coupling, has caught up with another problem in the meantime. I have installed a Variomatics, which has slightly increased the top speed. Now I heard a crash on my last ride. from the Variomatic lid and it flowed oil from it. On closer inspection I saw that the riser disc is broken and the simmering to the crankshaft is also over. Now to my questions: Since the housing on the crankshaft-simmering material has been sanded off, I have the fear that the new simmering will not hold. How do you see this? Can the damage have arisen due to the quality of the tuning accessory? Do you have a China scooter yourself and have with these similar Proble How do you appreciate the quality of the remanufactured spare parts that you can order from Amazon and co? I’m going to get some sinmering and an untuned variomatik. I’m looking forward to your answers.