My friend Benno bought a 2-speed Puch Monza from 1981. The engine sounded terrible, it had a very loud constant bearing whine. So we’re taking it apart, clean everything, replace the crankshaft, bearings and seals. I also had the chance to test my new ultrasound cleaner, which did a great job on the very filthy Bing 12 mm carb.
A quick video of the warped crankshaft:
I know it’s not the right way to check this, but the damage is obvious in this case. I think it must have less then 0,05 mm trow to be usable.