When running at 2500 rpm, the engine sounds right, the other gauges are all within Siltala-recommended ranges, and fuel consumption is 4–5 l/h.
Another Nauticat owner of similar vintage as mine told me that his owners manual says that his engine is governed at 2650. As everything else about the engine sounds, looks, and acts normal, it seems that it is not running as if without a governor. Maybe the tach is wrong. Perhaps unrelated but the hours-meter hasn’t worked since I bought the boat 4 years ago.