The 60 hp Mercury four stroke motors have been on the boat for nearly 18 months and had their 200 hour service yesterday. The decision to go from two 90 hp engines to the 60 hp was the right one for the size of the boat. The profile in the water is far better and the performance is more than adequate.
Fully loaded the boat will do 25 knots at 4000 rpm, a long way off the maximum rpm of 6000. At this level of throttle the fuel consumption is fantastic.
The huge reduction in fuel usage as well as the total lack of any repairs and other small mechanical things to take care of every week has been a huge improvement over the period. The requirement of only a fresh water flush between diving days to keep the motors in good shape has freed up a lot of time to work on other projects.
The only hiccup we have had was that the console-mounted hour meters both failed, one at 10 hours and the other at 60. Fortunately the engine management system stores this information so at the 100 hour service we had electronic units fitted. To access them one has to remove the engine covers, but this is a small inconvenience as they only need to be checked infrequently. At each service, we are able to get a detailed printout showing the activity of each engine, including how much time it has spent at what level of rpm.
