After my initial mishap with the engine on my first Fear trip, it was important to do some engine maintenance. These needs doing annually anyway, but we have been having issues with the engine, stalling out and not starting up reliably the first time.
The main jobs that needed doing were:
- Prop replaced
- Fuel filter replaced
- Water separator cleaned
- Fuel priming pump assembly replaced
- Heat exchanger cleaned
- New oil filter
- Oil change
- All jubilee clips replaced
All boats as they are in sea water have a main anode which is responsible for preventing corrosion. When we started checking things out on Fear we realized that the anode although in place, had never actually been connected to the engine earth. As a result, we were expecting a fair amount of corrosion over the engine. The biggest risk was the prop, without the anode it had corroded away and was soft and bendy and had to be replaced.
The next risk in the engine was the heat exchanger as this is fed with sea water. The heat exchanger is responsible for the engine cooling, it takes in sea water passes it through a set narrow tubes and cools the surrounding engine water. The heat exchanger itself has a back up anode and given that the primary anode wasn’t connected, checking the heat exchanger anode was one of the main priorities.
When we checked the heat exchanger anode, it no longer existed, having completely corroded away. Thankfully in doing this it had somewhat protected the heat exchanger itself. However, there were significant amounts of calcium build up and many of the narrow channels were blocked. The heat exchanger was also full of bits of the anode from when we had our first incident with the engine overheating. To be honest, it was a small miracle my engine had been working at all and thankfully having used the boat over winter the temperature was low enough to prevent the engine overheating.
To clean the heat exchanger, we soaked it in oxalic acid and cleaned all the channels using the end of a coat hanger as well as removing all the stuck bits of impeller. The heat exchanger anode was replaced, and the main anode was connected, to prevent this happening in future.
