While some of you are sitting here saying there is nothing to investigate, nothing to think about, nothing to comment about... there is new information coming to light.
I dont like copy/pasting from another forum, but we cant discuss it there for fear of family hurt, so I post here a post of info released by a family member:
For those interested regarding Nina's engine..
David had done a very good job on the install and had adhered to as much of
the advice that we gave him as he was able to
There was a few things such as the water intake that was not big enough to
allow maximum water flow to the engine at full throttle
Also the fuel lines were not of the correct size. These things would need to
be rectified before the warranty was signed off
The engine was quite capable of attaining full power however because of the
drive line alignment issues david chose not to go any higher in the rpm
On the sea trial the vessel motored at 6.5knots at 1600rpm. David was happy
running at a lower rpm that gave them 4-5 knots.
David was aware of the issues with the warranty and drive line and as he was
out of time he decided to address these issues when the vessel was slipped
The issues with the fuel lines and water intake would not have caused any
problems at the lower rpm.
I trust this will help