Thread crankshaft broken.locker screw with screw fuse?

Hello guys, I have a problem with my MBK Ovetto. Unfortunately, the thread of the crankshaft is broken and there is probably not cut back. Otherwise, the scooter is actually good, but a new crankshaft would simply not be worth it any more during the working hours. However, I only get the old mother on it, because she somehow milled her way there. I think in the long run we will be too loose. I thought about it already to just screw-securing on it to mac I mean more than that the crankshaft can’t actually happen completely. So my question would be now if someone had a better idea than screw securing? Thank you and many greetings.