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190 Amp Yanmar kits

240 Amp kit for Yanmar

330 Amp kit for Yanmar

190 Amp Yanmar belt kit

Fast Flow emergency bilge pump- Amazing flow

Inexpencive three step regulator

Marine books by
Scott Fratcher

Fast Flow emergency bilge pumps

ElectroMaax battery chargers

Fast charge rates

Inexpencive universial regulators


Engine change

We have perfected the one week mobile yacht engine change. Below are some examples of our system and work.

Step 1
We asses the existing engine installation, the fuel reserve of the vessel, the propeller apertures, the shaft diameter, the space available for the new engine and access to engine service points. With this information the owner can make a decision of what new engine to install. This step normally takes about two hours.

Step 2
Scott measures the existing engine and compares this information with the measurements for the new engine. This will tell us how the new engine will fit on the old engine beds. With this information we can design a set of engine rails to sit on top of the old beds. Scott then makes a list of materials that the owner collects while waiting for his new engine to arrive. The owner doing the shopping and expediting saves money and time. This step normally takes three to four hours of Scott's time and two to three days of shopping by the owner. Depending on the yacht's location the engine may be on the shelf (Panama City) or take up take up to two weeks in shipping.

Removal of an old Mercedes 636. Notice we have the floor and deck covered to protect the woodwork.


Step 3
With a pre-scheduled starting day Scott and the owner begin removing the old engine.  We normally have the old engine out and the new engine rails in place by the end of day one. At this point many owners choose to have the beds and open engine area painted. If we schedule this before hand we can leave a lay day for the paint to dry. If the owner is in a hurry we can just let the paint dry overnight with fans exhausting the fumes.


Step 4
We lower the engine onto the new rails and begin alignment. This is the slowest and most important part of the job. The lowering of the engine must be done carefully to prevent scrapes and dings to woodwork. Once the engine is on the new rails we slide the engine back and forth to line it up with the excising prop shaft. The shaft must be supported to place it just above center of the stern tube. If all goes well at the end of day two l have the new engine in place, sitting on the new rails, with the couplings together and in line. Sometimes this takes until the end of day three if the rails are especially challenging or the access was restricted.

Step 5
Bolting it all down. Once we have the engine in place we can begin to bolt the engine mounts to the rails. We have to be careful here because if we bolt the mounts down in the wrong place this wastes time and effort. We normally vice grip all four flexible mounts in place and then start by putting in one single bolt. Then we realign the engine to the prop shaft, re-clamp, and then put in the second bolt. By repeating this procedure eight times we now have the engine bolted in place and we are ready to begin hooking up the water, exhaust, diesel, etc. In most installations this will be completed on the end of day three.


Step 6
This day is normally the most fun and exciting for the owner. We can see the light at the end of the tunnel as we begin hooking up the salt water in, the diesel lines, the electrical, hooking up the exhaust, and all the little things that make the engine seem complete. By the end of day 4 we normally can start the engine and test the shifting.

Notice everyone is starting to smile.


Step 7
Sea trial. If you thought yesterday was fun, just wait till we put the engine in gear the first time and power up. No blue smoke, smooth start, big bow wake, large speed over ground showing up on the GPS, smooth engine, everything we had hoped for.

Scott always keeps a bottle of cleaner handy!

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Special considerations

Sometimes engine changes can have special circumstances. For example if the vessel had 40hp engine and the owner wanted to replace it with a Yanmar 75hp then the exhaust system may need to be enlarged. In the examples below you see a Perkins 4-108 being replaced with a Yanmar 75 hp and a 2" exhaust being enlarged to a 3". The prop was also changed from an 18" to a 22". This vessel, a Passport 40 achieved 7+ knots from a dead stop in about 8 seconds. Amazingly we changed another engine in a Passport that same season and only installed a 56hp in that vessel. Both had the same top speed, but the 56hp took almost twice as long to reach 7+ knots. For the vessel in a seaway that should mean the ability to motor into a heavy head sea with more punch.

And the boat is ready to go back into the water.

This was the process of enlarging the exhaust system and enlarging the prop. The old aqua lift built into the keel had to be opened and a new cover plate with the new SS tube installed. The old 2" through-hull was removed and a new 3" put in it's place. Much of this through-hull work was done expertly by Jason on Baggywrinkles.



Commonly asked questions

Question - What is this all going to cost?

The cost of the whole package varies wildly depending on Yacht location, equipment available to help with the change, and how much the owner wants to do himself. With all those varables we can start the pricing. 

The cost of the installation process normally runs about $400 to remove the old engine. $600 to build the new rails, place the new engine in place and align. The hooking up of all the extras is in the $750 range. This tends to be a total package of about $1700-$2500 in labor to change an engine. If the owner decides to add a dual alternator at this time they can normally save about $200 as we will have all our tools on hand. I must stress these prices are all general. Everything is time and materials. If the yacht was built with difficult access that takes more time and thus more money. The prices given above are general, but realistic.

Question - I have a Perkins 4-108 and I want to change it with the Yanmar 56hp. Are there any special considerations to think about?

This is a very common engine swap. There are two added difficulties. First the exhaust comes out on the port side of the Yanmar and the Starboard side on the Perkins. Sometimes the exhaust hose will just swing over, other times we have to make up a double 45 to reach the old aqua lift. This sounds much more difficult than it tends to be. The second challenge is the Yanmar has reverse throttle action on the injection pump. Push becomes pull, or however you move your throttle control right now will be reversed. The owner can choose to get used to his new throttle linkage, or Scott can build a throttle reversing mechanism. This can not be taken lightly. Engine control systems must be 100% dependable. If the throttle linkage were to fail during docking it could cause an expensive situation. For this we take our time and over build all shifting/throttle linkages. Notice below we used 1/4" plate on the system.

Question - Can I do some of my own work?

Sure, you can do any and all work. Scott works by the hour. You can have just a consultation where Scott can give you a detailed explanation of how to do your own work. Many cruisers are comfortable with much of there own mechanic work, but the thought of a complete engine change seems daunting. For that you could have Scott help with the consultation, remove the old engine, build the new rails, then align and bolt down the new engine. Then the owner can continue with hooking up the water, power, diesel, etc. We have helped install engines by just consulting and the owner took over. Other owners have had us change their engine by just communicating with us by email while they were in the states. The biggest single savings the owner can do on an engine change is the installing of the new instrument panel. This can take hours and needs lots of thought by the person who is going to be at the helm. This is a common area of savings for the owner.

Question - Does an engine change ever take longer than ten days?

Ten days would be long engine change. It all depends on whether more than a normal engine change is needed. Some things that can cause delays are the prop shop sending the wrong prop. Parts stuck in customs. Money transfers stuck in international banks. Most of these types of difficulties don't cost much money, just time. Things that cost money are the rare situations where the engine beds need to be cut down, or even more rare we find structural problems in the vessel itself. Also the one week engine change is for the basic engine change. Many times the owner wants to use the special access to the bilge to change all the bilge pumps, hoses, and wiring. This all adds to the total time, but this is normally planned out in advance.

Question - Does the boat have to be hauled for an engine change?

No, definitely not. In fact having the boat hauled makes the engine change more difficult. We need a very calm anchorage or dock and electrical power. Most modern yachts have an inverter and battery bank that will hold through the project. The boats used in these examples had special reasons to haul. For example one wanted to do a bottom paint and combine both projects to keep the number of down days to a minimum. The other was upping the horse power and thus needed a bigger prop.

Question - You mention Yanmar often. Do you install other engines also?

Yes, we install whatever engine or generator the owner chooses. We do tend to replace most power packs with Yanmar as they dominate the 12-100hp yacht engine market and I feel they are the best yacht engine made. Isuzu, Kabota and Perkins are also available but they don't tend to have all the options available. The other consideration is Yanmar is often an off the shelf item. You can walk into the Yanmar dealer and choose your engine on the day you want it. If they have to order they can have the engine in as little as four days. 



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