Xs400 dohc starts hardly and runs terrible

[bmaster]

Hi guys, I'm currently finalizing my xs400 seca rebuild.
The engine used to run better than this. When I was trying it during the building phase it ran pretty sweet. But now it doesn't..
When I ride on it, it won't go above 3k rpm.
In Neutral it doesn't go above 5k rpm

Current state: (idle + choke)

 

[bmaster]

This is a short movie with evidence that it ran better.. couple of hours earlier.

Could it be the case that the camshaft chain has moved? (Timing off)

It ran like this movie in the morning, in the noon it didn't start at all. Only thing I got were a few big bangs out of the exhaust.
After swapping the ignition caps from left to right and vice versa it started and runs like this.
Already replaced jets, adjusted pilot screw etc. So I don't think it's the carb.