Stripped that bike and started tearing the engine apart. I soaked the frozen pistons for weeks with all kind of penetrating oil. Not of them freed the rings, but I am sure it helped with I decided to use a peace of wood and hammered the piston. That worked right the way.
So, the engine was all teared apart, and I was looking at the main bearings that were worn out. And of course, it took me weeks to to finds a replacement for them. I was talking to Wingovations and he made a tip just for that http://www.wingovations.com/choosing...ngs/4588152247
I couldn't find the connecting rod bearings, so I reused those old ones. And they weren't that bad, just a normal wear.