The carburators are mercruiser set up for MCM575. Model 4500
Holley Part no 8082
Main jets .092
Secondary jets .092

I dont know if it has intermediate circuits, how can I find out?

Valves adjusted ok.

No Crossfire.

Valves look ok, not sticking what I can see.

I will test more tomorrow and if problem remains I will change carbs and see if the problem is on the engine or the carb. Today I lean towards lean mixture.

Thanks!
/Torbjorn

Problem solved!!

It was an electrical problem in the mercruiser contact between engine and the instrumentation, á bit more gap on the pins did the work.

Thanks for your help!!
/Torbjorn