After the chairs were removed, then we could proceed with the removal of the old engines. This is my old engine already taken out at the yard.
It still looks fine from this angle but the exhaust was in a terrible condition.
Notice that the exhaust was badly corroded and so were the exhaust manifolds which were not shown in this photo.
I could have a thorough look around the engines after they were taken out, and I finally discovered the problem that was causing my headaches all these while. One of the spark plug wires (light blue colour in the photo) was actually touching a hot part of the engine body and got burnt. It broke off immediately when I touched it. This explains why the engine was very unstable.
Looks like the health of your engine relies a lot on the meticulousness of your mechanic. My mechanic had looked at my engine ample times and he could not find this problem, costing me to spend lots of money on stuff without rectification.
This is the view of the engine compartment when it was empty. I repainted the compartment with marine epoxy paint since this would be the best time to do it.
Notice the two propeller shafts sticking out. That would be the point of reference to install the new engines.
Before repainting the engine compartment, I also removed the old transducer and patched back the through hull hole.
This is the newly painted engine compartment.
Re-power the boat does not simply mean change the engines. There are many other things that have to be done. One of the points, such as modification of the propellers, was actually highlighted in my earlier post - Last Days of My Engines - Part 3.
Propellers modified to increase the pitch from 18 to 19. Never see them so shiny before.
You will also need to change the shaft bearings.
This will ensure that your shaft will be tight fit during rotation thus improving power.
I also changed the power supply configuration of the engines. My port side battery used to act as the engine and house battery. This is not a good arrangement as the battery might run flat accidentally if you forget to switch off any electrical appliances in the cabin, and you will not be able to start your engine. So I installed another battery for the cabin which runs independently from the engine batteries.
However this gave rise to another issue. The house battery will not be charged by the engine alternator because it is independent. So I installed a relay, something like this.
When the relay is off, the house battery and the engine batteries will be disconnected. And when you want the alternator to charge the house battery while the engine is running, you can switch on the relay to connect all the batteries together.
You have to be familiar with the wiring before you attempt to do all these modifications.
The wiring can be quite messy if you do not have a clear mind. I will always take a photo of the original configuration before the modifications.
Running the concealed wires can be a challenge too.
You might have to dig into holes and squeeze into crevices to access or install the wires.
Other than the wiring, I also replaced the bonding system which will prevent the underwater metal parts from corroding too fast. You can google on bonding system to understand the concept in more detail. Basically you have to wire all the metals together so that there will not be any voltage difference between the parts. Any voltage difference will create currents to flow through the sea as the medium and the parts will corrode much faster.
This was one of the bus bars that was badly corroded. Some of the wires were broken already.
Putting in the effort to change all the bus bars and wires to new ones will help you save the trouble of replacing the corroded parts in the long run, which might be more costly and time consuming.
All these work really took a lot of time and effort to do. Special thanks to my dad who accompanied me to the yard every time to lend me a helping hand.
