I found, that Comco-Ikarus electric strategy is different than rotax.
On Ikarus diagram they used 3A fuse on C wire and they allow to disconnect C and B+ by switching off Master. They not using capacitor Too when the Rotax manual says that you can destroy regulator when disconnecting C and B+. In rotax they suggest to connect R,B+,C together before 25A breaker. In Ikarus manual R is totally not connected.
Question is, why they made so much changes and with way is better?
This is an C42 diagram: