Regular readers will have known that we have had a number of attempts at fixing our 3,000 hour yanmar including a new heat exchanger, all new cooling pipes, etc etc.

We were still unhappy with it and had disconnected the heavy duty domestic alternator which may have been part of the problem. Also, with our change to lithium batteries, we needed an alternator that the hungry lithium wouldn’t destroy or worse still cause to burst into flames.

The nuclear option is not stealing an engine from a nuclear submarine but actually was biting the bullet, admitting that we would never be 100% happy with the old engine and deciding to replace it for a new engine! Eye wateringly expensive but the equivalent of taking off and nuking them from space as they said in Aliens. As they said it was the only way to be sure!

Once you have chosen this path, there are a number of factors to consider. The easy part is the engine choice: the modern equivalent of our old engine is the 4JH110 which is a 110hp, turbo, common rail engine which is smaller than our old engine, a little more powerful (10%) and being brand new likely to have all of those ponies whereas our old engine was probably working at a lot less than the labelled 100 hp. Of course, a more powerful engine can cause more problems since you need to exercise a marine engine to avoid maintenance problems later which was also why we didn’t go any more powerful than the 110. We have seen a lot of people upgrade their engines and then struggle to get the benefit especially as the hull speed of the yacht is quite a limiting factor.

Unfortunately with the larger Moody yachts, the access to the engine is through the cockpit floor which means the removal of the cockpit table, the steering binnacle and then the floor. With the setup on Mariadz, you then needed to remove the Onan generator and the table it sits on before you could access the engine. Suffolk Yacht Harbour (SYH) were engaged to do the work to remove everything to get at the engine. initially, the cockpit floor has to have its outer seal removed and then the screws holding it in place need to be removed, the photo shows where these are but once removed the floor comes out quite easily.

The East coast dealer for Yanmar is French Marine and we engaged with them to understand the costs and what needed to be done. with our recent change to lithium we decided to supply our own lithium-friendly alternator and went with the Balmar 60-series 24V70A alternator with MC624 regulator and temperature sensors. This alternator recognises when the lithium is being too demanding and shuts itself down for a while to recover. It is also able to put a lot of power into the batteries quickly, an advantage when you are hoping not too run the engine for too long.

The work started, after some delays, and everything was going swimmingly. The old engine was ready to come out and would be available to sell, something that French Marine offered to help us with.

When discussing the work, one of the drivers was to have a quieter experience within mariadz when under power. To that end, we agreed to have all of the insulation for the engine room replaced. That would improve the soundproofing and hopefully make the engine even quieter.

While the engine was out, it was also a perfect opportunity to paint the engine room bilge. Once the table for the gennie was removed, we found some corrosion so we took advantage of it being out to have it regalvanised. You start to see how one job can lead to another… all of them seem quite reasonable in isolation but soon add up when done together. The new engine was in quite quickly but as part of the fitting of the shaft a problem was found with excessive wear, not surprising, I guess, after twenty years but a new one had to be sourced and fitted. We then get to the prop which had been out of the water for a while and had apparently seized. Clearly sending that back to the manufacturer is very sensible with everything else being replaced but again not factored into the project originally. It does mean that the entire drive train has been replaced which has to be a good thing.

Unfortunately, while all this work was being done, somebody left the companionway hatch open for an entire weekend of heavy rain. Some of the interior was under an inch of water which damaged the interior wood that we had just had redone in maple. This was very disappointing and caused additional expense especially when no-one admitted liability. Josh at Suffolk yacht harbour agreed to refurbish the companionway steps which had also been damaged by people walking on them with heavy shoes and damaging the edges, not a problem we had experienced before since we are a shoeless boat. This was a kind goodwill gesture but didn’t completely sweeten the taste of having to repair a lot of interior wood in the saloon. We were already having work done in this area so it extended that project and now looks excellent but wasn’t something we were intending to do.

You start to see how these projects add up and blow budgets. that may appear to be a repeat of what I said earlier but it seems so important it was repeating!

As an example, the generator is only a few years old and doesn’t have many hours however, we had a minor interior leak from a corroded part of the generator which needed to be replaced and we decide to have the whole thing properly serviced and checked before being out back into the boat. So now we know everything to do with the generator and engine have been checked, refurbished or replaced as appropriate and we can have confidence in our setup.

Suffolk yacht harbour then started to do the reverse of the start of the project, refitting the table, putting the generator back before replacing the cockpit floor. It is important that the cockpit floor is sealed correctly, since we know of at least one other moody 54 that had a problem here which caused all kinds of problems for the engine room. SYH did a good job of refitting this, resealing and then wet testing to make sure there were no leaks.

We then needed to commission the engine which was much later once a number of other projects had been completed. Initial work on this by French Marine was great and after a weekend of testing we found a slight leak from the shaft housing which was sorted quickly and efficiently. We now have a gorgeous engine room with two fantastic and efficient pieces of kit servicing our needs.

The whole project of the engine swap was a lot of money but the new engine purrs like Clyde eating his treats. We are also impressed by the engine power and have been keen to use the whole rev range as directed by yanmar during that crucial first 50 hours of use. But what of our old engine, I hear you say. 3000 hours is nothing for a good Diesel engine and there would be others who could use it. French Marine were as good their word and introduced us to someone who needed an engine. We agreed a fair price and I was able to offset some of the cost 🙂

Unfortunately the various delays on all parts of the project meant that we were unable to use the boat as much as we expected and eventually we had to leave SYH prior to finishing the first 50 hours. This meant that we would have to get the engine serviced on our route south to Plymouth.

We hit the 50 hours as we approached Southampton since there had been little usable wind and we had a weekend to make that trip. While in Southampton we were lucky to catch up with our good friends Christian and Jennifer which was great but also got us a couple of recommendations for someone who could service our engine. The second of these was Martin Smith who was friendly on the phone and able to fit us in to a busy schedule. He came on board at the time he said, which isn’t necessarily something we are used to, and did a thorough first service for us. We were really pleased with his work, approach and the result. The bill was also refreshingly reasonable too especially when the job had been quite short notice. An unequivocable recommendation from team Mariadz for Martin’s work.

So we now have a spotless engine room with mechanical parts in perfect working order and it is quiet when running, well as quiet as any boat can reasonably be!