This page details the removal and replacement of the Periwinkle II’s old single cylinder 6 HP Petter diesel engine with the new twin cylinder 14 HP Kubota Beta diesel. All descriptions refer to the photos below them.

This is the interior of the cabin looking aft as the boat was when we purchased it in July 2010. The engine resides under the cockpit, behind the removable steps. The lower step is bolted to the forward projection of the 2-1/2 x 2-1/2″ aluminum angle that form the tops of the engine beds.

This photo shows the old Petter as it was before being removed, looking aft toward the engine and old engine beds under the cockpit. The cooling water intake strainer and valve, which was seized, is awkwardly placed, and the aluminum engine beds project forward to support the lower step to the cockpit. The plastic container with the sponge catches the fuel dripping from the leaking fuel filter, and the rusting exhaust pipe leads aft from the single cylinder. Various bolts are stripped, and the cylinder had cracked and been welded at some time in the past, probably while a lake boat in Manitoba or the BC the interior. As the engine was raw water cooled, it would have had fresh water in the cylinder during the freezing winters on the lakes. You can see from the amount of oil and grease staining the beds and hull below it that the engine leaked oil in all directions.

The photo below shows the engine from the access hatch in the cockpit floor, or sole. The cockpit sole hatch was and is a huge blessing, enabling me to get at the engine easily from all sides. At the timeI purchased the boat it was unsecured by any hold-downs, though, a potentially dangerous situation at sea as it could be tumbled out during a broach or knockdown, allowing any water in the cockpit to pour unobstructed into the boat through a two foot square opening.

The photo also give a good idea of the general layout and the huge size and weight of the flywheel, clutch, and reverse gear in relation to the tiny single cylinder attempting to turn them. The engine did have one redeeming feature, which is that it could be hand started with a crank and compression relief valve. That came in quite handy on our first cruise as the previous owner had removed the generator, so there was no way to charge the battery while cruising, and I mostly hand started the motor to save the battery for emergencies.

Having decided the motor had to be replaced rather than rebuild, I removed the secondary components like the starter, air cleaner, and exhaust system to make it lighter and less awkward to remove, disconnected the electrical systems and controls, and unbolted if from the engine beds. The boat was conveniently located alongside the MBYC mast crane at the time, so I used the crane to lift it out through the cockpit sole access hatch.

Marlise operated the winch on the crane while I guided the engine out of the hatch and over the side. As usual in British Columbia at this time of year, this was done in the rain and dark, which is a general climate description of BC in the winter.

This is the new Kubota Beta 14 HP diesel replacement engine I purchased through the BC dealer, Gartside Marine, located in Sidney on Vancouver Island. Gartside is also a full service boat mechanical, electrical, and heating systems shop, and their knowledge of engine systems and installation made them a pleasure to deal with during the ordering process. I also ordered the new propellor shaft and prop from them. They had the engine air freighted in from England, and a friend and I picked it up at Vancouver Airport. As it weighs only 200 pounds, the two of us were able to simply pick it up, crate and all, and carry it into the boat shop by hand.

Here are the old and new engines side by side in the boatshop in my back yard. The old engine is actually 6″ longer than the new one, and slightly heavier. It looks smaller in the photo partially because the new engines is closer to the camera, and partially because the new engine has a fresh water heat exchanger cooling system, on the left side in this photo, and  the generator, starter, air cleaner, and exhaust system have been removed from the old engine. So although it is more than twice as powerful, the new engine will actually take up less space in the boat.

This greasy mess of rusting iron, hoses, wires, and cables was what confronted me once the old Petter was removed. All of it had to go, and the entire area under the cockpit needed to be cleaned up, ground down to clean bare fiberglass, old through-hulls removed, filled and relocated, the hull and bunk sides strengthened to support the more powerful new diesel, and new engine beds for the Kubota built and installed.

Ugly,  Ugly,  Ugly . . . . grease, oil, and rust everywhere. This was not going to be a five minute clean-up job.

I started by removing the old metal engine beds and wiring from the plywood and fiberglass underlying structure.

With clear access to the old plywood and fiberglass beds, I used the Sawzall to **VERY** cautiously  cut the cross-members away from the engine bed stringers, being extremely careful not to cut into the hull in the process, and finishing the cuts with a hand saw. Note the two holes in the hull by the Sawzall where the cooling water intake and a knotmeter impeller had been.

Those holes needed to be feathered out and the hull built up solidly with new fiberglass. Here is a look at them from the outside of the hull after removing the cooling water through-hull and knocking the covering paint and fairing compound off the filled-in knotmeter hole.

I removed the remnants of the knotmeter left in the 2-1/2 inch opening by some previous amateur hour boat fixer who had simply sawn it off inside the hull and stuck a woodscrew and some filler into the remaining bit of the plastic through-hull fitting. You never know what kind of “repairs” previous owners may have done to a pre-owned boat until you remove the exterior paint and interior liner and discover them hidden away behind some fairing compound. Little did I know when we headed off across the Salish Sea on our maiden cruise that some Bondo with a wood screw through it was all that was keeping the Pacific Ocean on the outside of the hull!

Here I am cutting the old engine bed cross-members into ‘bite sized’ sections that could be more easily removed without risking damage to the hull while prying them off the fiberglass.

With the cross-members cut into small pieces, I carefully pried them off the hull so I could get at the main engine beds and start working them loose.

Using sharp chisels I gradually pried the old fiberglass engine beds off the hull by sliding the chisels under the edges of the fiberglass fillets and gently working them in to lift and separate the engine bed fiberglass from the hull glass it was bonded to.

And finally the old engine bed fiberglass structure is delaminated from the hull and tipped aside.

Followed by the inevitable clean-up, of course. With the engine beds out of the way I can get at the hull to clean up the greasy and rusty mess and grind it down to clean fiberglass, and get at the area under the cockpit to remove the old cockpit drain through-hulls and repair the area around the propellor shaft tube and the aft cabin bulkhead.

Here is a closer look at the aft cabin bulkhead supporting the aft end of the cockpit and the rudder post. Various holes had been cut in the plywood and never sealed properly, and the lower rudder post bolts were corroded and needed replacing. I decided to cut out and replace a rectangle encompassing the three holes at the top right as the wood around them was weakened and rotted a bit by rainwater around the holes.

There was a lot of some nasty hardened pitch-like material stuck to the hull ahead of the aft bulkhead which had to be scraped off with a chisel and then ground clean.

Here I am using the Sawzall to cut out the rectangle encompassing the three holes in the aft bulkhead. The edges are intentionally steeply angled out to get a larger surface area on the bulkhead and filler piece for the epoxy glue to bond to.

Here it filler piece is being test fitted and faired in read to glue in place.

And the filler piece of plywood is epoxied into place . . .

. . .  and with the corroded lower rudder post bolts knocked out everything is faired and ground off ready to fiberglass the aft bulkhead.

Here the first two of 8 layers of strengthening fiberglass is in place on the aft bulkhead, lapping onto the hull and the underside of the cockpit sole to secure them to the bulkhead.

Not the easiest or most convenient location to do fiberglass work.

The bulkhead has now been strengthened to properly support the rudder post on the aft side of it. In the foreground of this photo you can see the ugly mess of amateurish fiberglass covering the propellor shaft recess, apparently in an attempt to stop water from a leaking stern bearing bolt from coming in. This was one of the next areas that needed to be dealt with.

I started by carefully chiselling out the crude fiberglass layup covering the propellor shaft tube recess, which turned out to be full of water.

There was quite a lot of debris generated as I worked my way down into the propellor shaft tube recess and back out along the hull toward the quarterberth sides, removing the old fiberglass.

With the rough fiberglass patch and old caulking removed the leaking bolts holding the stainless steel shoe in place were exposed.

Here is a look at the propellor shaft tube and shoe from the outside. The two leaking upper bolts shown in the photo above have been removed. The lower bolt was through solid fiberglass and wasn’t leaking as it had no where to leak to. I replaced it with a new bolt as it was a bit corroded.

With the leaking bolts removed and the area dried out, I was ready to fill the hollow with solid fiberglass material. This was a good place to use up all the odd cuttings I had laying around. I laid up several layers of woven roving and mat across the bottom and down into the hollow so they would give it lateral support, and then filled it up with scrap fiberglass cuttings.

The forward end of the propellor shaft tube was carefully cleaned and solidly glassed in.

And then I laid up the final five layers across from one quarterberth side to the other, locking the shaft solidly in place and strengthening the bottom and shaft for the more powerful new motor.

Next came the very nasty job of grinding down and fairing up the new glass and the next section ahead of the shaft where the new engine would be mounted. Not fun.

This was definitely a full “Moon Suit” job.

Even the full chemical mask and hooded coveralls don’t keep all the dust out. I always try to breath through my nose when sanding or grinding so my sinuses can catch some of the dust that gets past the mask. Fiberglass grinding is among my least favourite jobs, with the horrible itchy ground glass particles getting into your eyes and skin no matter how well you cover up.

With the grinding done,  I laid up five layers of mat and woven roving to reinforce the hull and quarterberth sides where the new engine would be located.

Simultaneously with the inside work, I was fairing out and filling in the holes where the various old through-hulls and knotmeter impeller had been removed. This pair were the old cockpit drains.

The large hole was the knotmeter impeller, and the smaller hole ahead of it had been the engine cooling water intake. Further aft there were two small bolt holes where some unknown object had been bolted to the hull and later removed by someone.

It all had be be faired down with a long shallow taper that so the new glass would get a good strong bond to the hull, and then laid up with several more layers on the inside of the hull later on.

I taped wax paper across the holes inside the hull so the fiberglass resin wouldn’t stick to the backing blocks and jammed them into place so I had a solid surface to fiberglass against.

Next came laying up the fiberglass against the backing blocks to fill the holes securely.

I covered the three holes at the aft end of the keel with a single patch rather than three small patches as it would get a better bond to the hull and be much stronger.

With the outside patches in place and ground down to fair smoothly into the hull, it was time to complete the hull repair and engine bed strengthening on the inside. After applying the inner strengthening patches, I laid up five layers of heavy woven roving alternated with 2 ounce mat across the bottom and up to the top the bunk sides. This complimented the layup on the inside of the quarterberth compartments, the rebuilding of which is a separate story covered in the general Rebuilding the Periwinkle II | Cruising Under Sail.com page.

Once the hull and engine bed fiberglass reinforcing was completed and ground down from the aft cabin bulkhead to the forward end of the engine compartment it was time to crawl back to the aft end of the space below the cockpit where the new fuel tank was to be installed and build and install the fuel tank support beds. Having determined the angle between the slope of the hull bottom and the vertical sides of the fuel tank I laid up a pair of fiberglass support beds over a form matching that angle and cut and ground down the cured beds into the desired structural pieces.

With the two fuel tank support beds built, I determined the exact location of them and glassed the first one onto the hull. They are somewhat off centre to allow for passage of the large 2-1/2″ diameter engine exhaust hose on the port side and the much smaller engine control cables on the starboard side. The port side was fitted and installed first.

And the starboard fuel tank support bed is glassed into place. As the new fuel tank is 16 inches wide I used a  16″ wide scrap plywood spacer to position the second bed exactly parallel to the first rather than try to position it against some hard to see marks on the hull. The holes for the fuel tank filler hose, on the left, and the exhaust hose were cut through the aft cabin bulkhead at this time and lined with fiberglass to protect the exposed plywood edges.

The forward ends of the fuel tank beds were built up a bit on the outside to provide better support for the bolts at the forward end of the tank which hold it in place.

About this time I also repaired and reinforced the engine control recess in the starboard cockpit side. It had numerous holes through it where control handles, cables, and bolts had been that needed to be sealed up and reinforced. This was another of those awkward areas to work in under the cockpit and in the quarterberths.  I was really looking forward to getting out from under the cockpit into the main cabin where I could move around a bit.

The engine controls recess was a difficult area to glass as the multi-layer structural glass elements did not like to bend around the complex shapes.

The next item to be dealt with in constructing the new engine beds was to determine the exact angle and height of the propellor shaft centreline and transfer it to the bunk sides where the new engine beds would be bolted on. The base of the engine mount ‘feet’ at average height adjustment are in line with the output shaft centreline, so the top of the engine beds needed to be precisely that height and angle. I started by pulling a string down the centre of the propellor shaft tube.

To do that, I jury rigged a vertical post in line with the centreline of the boat and propellor shaft tube  and moved the string up and down to get the exact angle. Next I placed a spirit level across the bunk tops, making sure it was actually level (the boat had already been levelled) and square to the centreline, and then transferred the distance from the string to the level over to the bunk sides at various points along the bunk sides to get a series of height marks.

After that it was “connect the dots”   😉  to get the actual lines for the top of the engine beds.

Part of the engine compartment work involved the general upgrading of the engine compartment hatch support coaming and the construction of a pair of support posts at the forward end of the cockpit foot well. Here is the underside of the hatch support coaming after all the fiberglass work  was completed. This was difficult work as it involved laying directly under the work area and wrapping the reinforcing fiberglass layers around the tight 180° bend at the bottom of the opening and back up the other side. Since it was upside down, the stiff glass of course wanted to spring open on either side of the wrap-around, constantly creating air pockets and trying to fall off, necessitating continual rolling out until the resin started to set. In the end it came out very well.

One of the problems that concerned me was the lack of support at the forward end of the cockpit, which was suspended from the side decks with no direct supports to the hull. As part of the cockpit coaming and engine compartment reconstruction I built a strong fiberglass support post on each side of the cockpit at the forward end of the cockpit footwell adjacent to the cockpit drains where the post would also serve as a shield protecting the drain pipes from being banged into by people or gear in the adjacent quarterberth. I first took the weight of the cockpit onto a couple of temporary 2×4 support blocks to remove any sag in the side decks, and then laid up the new support posts.

Once the fiberglass had cured I ground the posts to their final shape, ready for painting.

And here the posts are completed, ready to proceed with installing the support for the propellor shaft forward bearing and stuffing box, and building the engine beds.

I first made a cardboard template of the propellor shaft bearing support piece and then laid up a 1/4 inch thick flat piece of fiberglass and cut it to match the cardboard template.

Next I fine tuned the fiberglass support to fit snugly against the hull with enough space under it for several layers of fiberglass. The idea is to lay down some fiberglass mat and then bed the support piece into it with the propellor shaft wedged in place to hold the exact position until the resin sets.

As the hole for the stuffing box / bearing is purposely cut larger than the diameter of the bearing to allow for a vibration dampening rubber grommet, I wrapped some tape around the bearing to bring it up to the same diameter as the hole to get the support piece exactly centred.

With everything aligned and ready to go, I bedded the support piece into the wet fiberglass mat.

After the support piece was set into the wet fiberglass and cured in place, I cut the fiberglass support fillets on both sides of it to bond it securely to the hull. The forward fillets ran about a foot further forward and served to strengthen the hull at that point for the cockpit drain through-hulls.

With the fiberglass all cut and test fitted, I mixed the resin and bonded it into place.

And at last the propellor shaft bearing support is finished and sanded smooth and the cockpit drain through-hulls have been drilled through and test fitted. Like a lot of things in this area, they can’t be permanently installed until the fuel tank is installed, which in turn is waiting for the painting to be completed under the cockpit and the fiberglass work to be completed in the main cabin so that fiberglass grinding dust won’t get into the area behind and under the fuel tank where it would be difficult to remove.

After installing the propellor shaft support, the next step in building the new removable engine beds was to tape some wax paper onto the bunk sides so the glass wouldn’t stick to them, and lay up several layers of fiberglass against the bunk sides to get the desired shape for a snug fit so the bolt-on engine beds would fit seamlessly against the supporting bunk sides.

When the resin cured I pried the vertical pieces of the  engine beds off the bunk sides and trimmed them to the desired shape, grinding then down to a flat but slightly rough surface that the next layers could get a secure bond onto. I then fitted them back in place and drilled the first group of bolt holes through them and the bunk sides so I could bolt them on for the next step. With the side pieces bolted in their exact locations I transferred the lines back onto them for determining the top of the engine bed horizontal pieces.

Next I built some temporary supports at the required positions to match the angle of the propellor shaft and scribed a pair of previously laid up flat fiberglass pieces against the vertical pieces by sliding them along the temporary supports up against the vertical pieces which had been temporarily bolted in place, ready to lay in some fiberglass fillets to connect the vertical and horizontal components of the engine beds into a single unit.

The horizontal and vertical pieces were then bonded together in place with several layers of fiberglass to get a basic engine bed structure that precisely matched the supporting bunk sides.

After separating the newly bonded engine beds from the bunk sides, I ground the excess fiberglass off them and prepared them for  the rest of the multi-layer layup to about 1/2 inch thickness.

I built a jig to hold them in a convenient position for building up the fiberglass layers on the top and bottom of the engine beds and proceeded with the layup, which was done in the boat as it was still winter, and the unheated boat shop was too cold for resin to cure. Inside the boat a small heater was able to keep the temperature warm enough for fiberglass work.

After laying up the strengthening layers, I trimmed off the excess fiberglass with the jigsaw . . . .

. . . and then it was back to the grinder, my least favourite job, to carefully clean up and flatten out any bumps and round over the edges. You never want any sharp edges on the inside of a boat, since you may get tossed against them in a seaway.

With the basic engine beds trimmed to shape, I fitted them to the bunk sides and double-checked the propellor shaft angle against the top of the engine beds where the engine mounts would bolt on.

Having determined that the height and shaft angle were correct, I drilled all the remaining bolt holes for securing them to the bunk sides.

The next item on the engine bed agenda was to determine the exact location of the engine mounts on the engine beds so I could build the supporting triangle gussets directly under the engine mounts. To do this I temporarily installed the new propellor shaft and propellor to determine where the flexible coupling would come against the engine coupling. This gave me the fore and aft position of the engine, and from that I could determine where the engine mounts would sit on the engine beds.

Having determined the precise location of the engine mounts I made up some flat triangular fiberglass pieces and scribed and bonded them to the engine beds so the stiffening gussets would be directly underneath each engine mount, with one of the two mounting bolts on each side of each gusset. 

The gussets were then laid up to about 1/2 inch thickness with the fillets lapping about 3 inches onto the horizontal and vertical sections of the engine beds and bonding them securely into a vibration and flexing resistant unit.

The purpose of the gussets was not so much to support the weight of the engine as to prevent flexing and dampen vibration. The engine only weighs about 100 kilos (200 pounds), while the engine beds could comfortably support several tons! The gussets were tediously cleaned up with a grinder where I could access them, and finished off with chisels and a lot of hand sanding.

And here we see the completed engine beds temporarily test fitted in place before being removed for painting. “Permanent” installation – they can be unbolted if necessary in the future – will have to wait until the fuel tank is installed as the fuel tank has to be slipped into it’s beds (where the heater is in this photo) from the engine side and can’t fit past the engine beds. Hence the need to have the beds bolted on so they could be removed if the fuel tank ever started to leak along a seam. Since it is a brand new all welded pressure tested stainless steel tank, that is not very likely, but better to make provision for it in case Murphy’s Law rears it’s ugly head in the future and some pinhole corrodes through a weld.

With everything test fitted, ground off, and finish sanded, it was time for me to get out of the way and let Marlise get on with the painting under the cockpit and around the engine bed area. She put five coats on everything, lightly sanding between coats with 220 grit paper to ensure a good bond.

The engine exhaust goes through the large hole in the aft cabin bulkhead on the right, and the fuel tank filler pipe goes through the smaller hole on the left. The fuel tank slides over the propellor shaft support and into the beds behind it. Once the fuel tank is in place, the cockpit drain and engine cooling water through-hulls can be installed in the holes in front of the propellor shaft support, and the engine beds bolted in place.

Just for contrast, because it is so easy to forget just how much this area has changed, here is what the engine compartment looked like immediately after removing the old engine.

And the back end looked like this, with the rotted aft cabin bulkhead and rust and pitch everywhere.

Its a bit cleaner now, and *much* stronger from a structural point of view, especially as regards supporting the forward end of the cockpit and the propellor shaft bearing, which are no longer just hanging in the air. This section is now ready to install the fuel tank, bolt on the engine beds, put in the through-hulls, drop the engine into place, and start hooking up the engine systems and controls. The hold-up is fiberglass work going on further forward, which is generating lots of very nasty fiberglass grinding dust. If I install the fuel tank, engine, wiring, fuel, and exhaust systems now it will be very difficult to keep the fine ground glass particles from getting everywhere, and they would be almost impossible to clean up with this area filled with machinery, so I have to reluctantly wait until the fiberglass work is completed and the last of the dust vacuumed out before I can slide all the machinery into place, much though I want to do that right now. Frustrating! But better to do things in the proper sequence or you just wind up making extra work for yourself.

Here is a comparison photo of the new 20 gallon fuel tank with the old 2 gallon tank sitting on top of it. We shouldn’t need to be topping up the tank half way across the straits any more.

To be continued as the work progresses . . .

* * * * *

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Return to top of Home Page: Cruising Under Sail.com | Messing about in boats in British Columbia, Canada.

Currently Marlise and  I are working on rebuilding our 26 foot sloop, the Periwinkle II: The Periwinkle II | Cruising Under Sail.com

Details of the rebuilding project:  Rebuilding the Periwinkle II | Cruising Under Sail.com

Completing the Main Cabin. | Cruising Under Sail.com

Rebuilding the Galley. | Cruising Under Sail.com

Replacing the Diesel engine. | Cruising Under Sail.com

Rebuilding the Forward Cabin. | Cruising Under Sail.com

Rebuilding the Steering System. | Cruising Under Sail.com

Installing the name and registration. | Cruising Under Sail.com

Rebuilding the Head. | Cruising Under Sail.com

Rebuilding the Lazarette. | Cruising Under Sail.com

Rebuilding the Mast Support. | Cruising Under Sail.com

Rebuilding the Quarterberths and storage compartments. | Cruising Under Sail.com

Refitting the Mast, Rigging and Sails. | Cruising Under Sail.com

Replacing the Forward Hatch. | Cruising Under Sail.com

The Other Details. | Cruising Under Sail.com

You can read about my early days in and around Crescent Beach and the Gulf Islands here: Beginning at the beginning . . . | Cruising Under Sail.com

And the Periwinkle Catamaran here: The Periwinkle | Cruising Under Sail.com

I also have a 26 foot Cape Cod Catboat under construction in the boatshop in my back yard which you can read about here: The Catboat | Cruising Under Sail.com

You can read about some of our cruises here as I get time to post them: Cruises | Cruising Under Sail.com

Our first cruise in the Periwinkle II | Cruising Under Sail.com

It was a Dark and Stormy Night | Cruising Under Sail.com

You can read all about Wards Public Marina and the facilities it offers on this page: Wards Marina | Cruising Under Sail.com

And finally a bit about the author: About | Cruising Under Sail.com