Trouble shooting to find faults on boats can sometimes be a painstaking task at best.
I recall the story of a vibration issue on a particular model of a production boat brand years ago. It apparently took the company twelve months and a million dollars to resolve, but eventually they did.
After purchasing specialist vibration detecting equipment, changing props and investigating many other unlikely causes, It turned out that the new underwater exhaust system was not matched to the engine horse power. The resulting harmonics created the vibration. Simple as the solution was in the end, I learnt that boats and boat manufacturing is not an exact science. I call it the ‘Human Factor’.
A more recent overheating problem on a late model 62 footer has taken eighteen months to resolve and the cause has been equally as elusive.
Under full power, one engine was triggering the over temp alarm. Cooling systems were checked many times, propellers removed and balance, impellers replaced. Everything checked out OK but still the engine temp kept on rising and triggering the alarm
The owner of course at this stage was getting a little frustrated that his near new motor yacht was not performing.
Finally, after many communications back and forth from the vessel and engine manufacturers across the globe, some one suggested changing the coolant blend.
Remarkably, this solved the problem.
Never in my 30 something years in the industry have I come across this little gem!
Anyway, everyone is happy now and I can add yet another item to my trouble shooting checklist.