Starter Motor Relay engages the starter motor during operation?

[eddievan]

I have a Yamaha 115 hp 2-stroker manufactured 1998 and yesturday I experiensed that the engine stalled during a 20 knot run.
I had just previously made some turns so the engine was normal warm.
I had started it 2-3 mins before it stalled
After I came to a complete stop the first thing noticed was that all electrical power was lost, the MFD and FishFinder and engine instrument was off
Then I noticed that the 80 AMP C/B had opened
Once cooled I reseted it and try to start, I heard the Starter Relay Click and the the C/B opened again.
Tried one more time with the same result
Back at home I disconnected one of the leads to the Starter and no the C/B did not open.
Then I made the day and a beer

My thinking;
Did the starter relay engaged the Starter during the run?
Is that a possible cause?
Is it even possible, isnt there some kind of protection for that?
Is it a "well known" fault casue?

Thanks for your input and I wish you a great weekend

Brgds Bo
www.eddievan.com

[eddievan]

After short trouble shooting I found that the cylinder no 2 (top left side , viewed from rear) has a "non moving piston".
I guess the conneting rod is broken.