Find the Yanmar
manual on the boat
If not, you can download one for your specific engine
(model number should be on engine
plate) - multiple sources.
It will tell you Max RPM
& give running + care instructions
of thumb - 80% of max is a good max to observe....run all day @ that level....although you can improve (even more) fuel
efficiency by dropping it even further.
Turbos need a little extra care (cool down & "blow Out" every now & then) - sure owners will chime in
5000 - just a dial face number
Enjoy the new yacht