A bit past 1180 h on the boat now, throttle control replaced at around 1000 h, and everything worked fine for about 100 h after that. Neutral switch still works fine which was another reason for the replacement.
Connectors att the tranny have been checked, maybe not so thoroughly, will have another look, any idea on how to measure this intermittent problem at the connectors?
Once again, really appreciate all ideas, great forum!