When I bought Priorities, it was equipped with a 15 year old Entec West diesel generator. It ran okay for only the first few outings, then became difficult to start. I spent way too much time fussing with it, maintenance access was horribly uncomfortable, it smelled during and after use, and parts were hard to find. Eventually it became so unreliable I actually went several seasons without getting any practical use of it. It also took up the entirety of our port lazarette. After figuring some of the issues were related to poor installation that I couldn’t really fix, I eventually came to the conclusion that removing it was my best option.
Do I Need a Generator on my Boat?
Deciding on whether I really wanted or needed another generator was not a straightforward decision. I was able to occasionally use the old generator for a total of about 150 hours over the first few seasons I owned the boat. When it did run I learned that it was quite a bit quieter than the propulsion engine, allowed us to quickly charge our batteries, heat our hot water heater, and power our air conditioners to heat or cool the boat. If we ever cruise to salt water (we thought we actually might when I started this project), being able to run a high capacity AC powered water maker rather than a DC one sure would be nice, too. We typically used other AC devices, like the microwave and toaster, during “generator time,” too.
Almost all these tasks can be accomplished when running the propulsion engine, and/or with the inverter. Our solar panels help with battery charging, too. Having fewer mechanical systems on the boat means less cost, less maintenance, and less to go wrong. However, because of my work schedule, much of our cruising is in the later parts of summer into fall, and there have been plenty of times at anchor where I wished we had heat… not something that the inverter is well suited for. It seemed like cloudy days were more frequent in the fall, too, in addition to the days getting shorter, cutting solar panel output. When the sun was out, it also seemed silly to run the engine just for hot water.
Getting a portable gasoline generator like a Honda 2000 didn’t seem attractive to us since we’d have to carry a bunch of gasoline, and gasoline has special storage considerations on a boat. Our dinghy is electric, so we don’t currently carry any gas on the boat at all. I’ve also been near other boats that ran a portable gas generator in the anchorage, and the sound was obnoxious. I don’t want to be “that guy.”
I considered adding a hydronic heating system instead of a generator, which could heat the cabin and run the hot water heater. It would add to our 12v power consumption rather than charge it, though. It also would be pretty expensive, and was still a complicated install.
So do I NEED a generator on my boat? No… but I don’t NEED a sailboat, either!
I settled on the idea that a diesel generator would be “nice to have,” but was only worth it if I could have reasonably good maintenance access. So I started taking lots of measurements and looking at lots of generator designs. I’m not a marine professional, and I was intimidated by some of the technical issues of this project. I also knew this project would take a lot of time… but I had lots of time off from work during the pandemic this past winter.
Removing the Old Generator
Removing the old generator was actually fairly simple. With the boat hauled for the winter with the mast up, Kristin and I had plenty of halyards, winches, and blocks to lift the 170 lb. generator out of the lazarette and down to a scaffolding on the ground. From the scaffolding I could easily slide it on some plywood into the cargo area of my Subaru Outback.
As for disposing of it, eventually I decided to leave it in the alley behind my house and hoped a scrap metal guy would drive by and take it. It was gone in less than 14 hours!
Planning for a New Generator
The only practical location on our Catalina 400 for a diesel generator is one of the lazarettes. The old generator and associated infrastructure was installed in the port lazarette, so this was the likely location for anything new. It’s a super tight space, though, and I knew from previous experience maintenance would be difficult with anything installed on the old generator shelf.
So I thought a little more “outside the box.” Catalina 400s have two externally vented compartments on the transom… one is a propane locker, the other either extra propane or gasoline storage. Removing the “extra” locker would give me a lot of space in the port lazarette. We’d lose the extra propane tank, but one tank can get us through an entire season comfortably, and we could probably store a spare in the anchor locker during more extended cruising. Besides, boats are always compromises!
In my research I learned you need more space than just for the machine itself. Highest on my list of requirements… a deal breaker… was the need for a comfortable work space around the new generator, including room to remove any sound enclosure. Exhaust hose needs to be routed to a water lock (or “Vernalift”) muffler, the top of which is at least 12” below the water injection point of the exhaust elbow… so we need room under the unit, too. Since we have a sailboat, the muffler should be close to the centerline of the exhaust elbow to keep seawater from sloshing into the cylinder when heeling. The highest exhaust point after the muffler needs to be well above the heeled waterline, too, so waves don’t splash in and down. In addition to needing room for the exhaust, you also need a fuel filter and raw water strainer nearby.
I also realized installation would probably involve cutting some fiberglass to make the frame of the lazarette lid larger, otherwise nothing would fit through the opening. Later model C400s may not have this issue, as their lazarette lid has a much bigger opening than earlier models like mine. At first I was hesitant to cut an access panel, but then I saw a brand new Catalina 445 at the Annapolis Boat Show that had done exactly this in order to fit a generator in their lazarette.
Comparison Shopping
Eventually I settled on two candidates for generators in this space: the Fischer Panda 5 (or “AC 5000”) and the NextGen UCM 1-3.5. I wish I could have run the two next to each other while comparison shopping, but I had to guess about noise level instead.
The Fischer Panda 5 is a fairly new design with a two cylinder engine, so is probably smoother and more powerful. The generator portion is directly connected to the engine portion, so the whole machine runs at 3600RPM (60 Hz * 60 sec. = 3600RPM)… so it might sound a little “whiny.” The generating section is water cooled, so no air cooling needed at all. It has very good documentation, too, though this is offset by added complexity. It weighs a little over 250 lbs.
The NextGen is cheaper, and a somewhat better fit for the space since it is shorter vertically. Since the generating section is belt driven with a pulley ratio to get 60 Hz, the engine section runs at a lower 2800 RPM that should yield a more pleasant tone. Its 3.5kW output, while smaller than the Fischer Panda, is actually good for our planned power demand. Running a diesel under moderate load is usually more desirable than running lightly loaded for extended periods of time. The engine section is liquid cooled, but the generator portion requires a fan for air cooling that I worried could be noisy. It is built with mostly generic, off the shelf parts, and the overall design is pretty simple. Customer service on the phone was excellent with answering my questions, too. Weight with the sound enclosure is around 200 lbs.
After a bunch of careful measurements and planning, I narrowed my choice to the NextGen. I didn’t actually place the order for it until the propane locker was out and I was very sure it would fit.
Removing the Propane Locker
With the old unit out, I could take a closer look at the remaining space and remove the propane locker. The propane locker is actually a separate piece of fiberglass joined to the hull by a flexible adhesive like 5200. I disconnected and capped the drain, making sure the primary propane locker still drained correctly. Removing the locker was only about a two hour job of careful cutting and prying.
One of my objectives of this project was for all my modifications to be reversible. I removed the propane locker without damaging it, so if I or a future owner want to remove the generator I can get the boat back to its “stock” configuration.
Once it was out, I remeasured and planned everything again. Using a carefully laid out cardboard mockup of the NextGen, I confirmed that not only would the generator fit once installed but I’d also be able to lower it into place without completely disassembling it. Finally sure that it would fit, I placed my order.
Delivery
Normally a boat owner would work with a dealer when purchasing a NextGen generator, but there weren’t any close to me in Milwaukee. Since I did this project myself, I worked with NextGen directly and had it shipped to my house via truck freight. It took about a month from order placement to delivery, though this was during the pandemic. While the unit itself is only about 200 pounds, the shipping weight is 300 with the pallet, boxes, and accessories. Fortunately, the driver brought the pallet on a dolly right to my garage, where I could start preparing for its install.
The generator arrived already installed in the sound enclosure, which was mounted to the pallet. Kristin and I removed the generator unit from the sound enclosure simply by lifting it… the machine part only weighs 150 pounds. I took measurements to verify my mockups were correct, and took pictures for future reference.
Mounting Base and Opening
Eventually I decided to build a new shelf to mount the new generator along the outboard side of the lazarette, and rebuild the existing shelf that had held the old generator. The old shelf would partially become a seat for me to make installing and maintaining the new generator much more comfortable than before. This also wasn’t my original planned orientation, but seemed to be the best spot as I sat inside the lazarette visualizing myself performing maintenance. On the NextGen, the exhaust water injection point is 9” above the enclosure base, so we could get our needed 12” drop to the muffler top pretty easily.
Measuring all the compound curves in this compartment is very difficult, so I made cardboard mockups of the shelf supports before cutting them from marine grade plywood. The new shelf supports were glassed into the hull and painted with a bilge paint. I kept the old shelf supports, which were way overbuilt, simply because removal would have been difficult. I wouldn’t have gained much storage space, anyway, since a rudder tube brace is in that area as well.
The shelf is two ¾” marine ply pieces laminated together to reduce vibration, the top surface covered with epoxy for fuel resistance, then painted. The old shelf was not epoxy coated, and still smelled like diesel months after removing it from the boat!
To reduce vibration transmission, I mounted the enclosure on isolation mounts in addition to the isolation mounts between the enclosure and the unit. I actually used the same type, too, and ordered them from NextGen. I test mounted the enclosure base to the shelf at home so all the bolt holes would line up once it was aboard the boat, then disassembled it. Based on my measurements, I knew I’d have to slide the enclosure around during install, so until the generator was actually in the lazarette I kept the enclosure base unattached. I also didn’t want the hose and wire pass throughs in the standard locations on the enclosure base, so I had NextGen NOT drill these at the factory and drilled them myself at home.
After some careful measuring with the cardboard mockups, I cut the access panel to make the lazarette lid bigger with a jig saw. I have to admit, cutting this big hole was pretty terrifying! At home I added a flange with some G10 fiberglass to aid in reattaching the panel after installation.
Accessory Components
I chose a 1 gallon muffler from Centek (purchased from Defender) and mounted it on a backing plate close to the rudder tube. It couldn’t be too far inboard or outboard of the exhaust elbow, but I needed room to put my feet when working on the unit. I’m pretty sure we’d have to heal over way, way more than normal before water could splash up into the exhaust manifold… and I think the propulsion motor would be affected first. My exhaust hose is routed as follows: through the enclosure base and shelf support, against the stern, forward and down to the muffler, then straight up to the back of the shore power outlets well above the heeled waterline, over the generator sound enclosure, then down to the exhaust thru hull a few inches above the static waterline. In the future I can add a water separator to reduce exhaust noise more if I want.
Because the exhaust manifold can get very close to the heeled waterline, I needed a vented loop after the raw water pump and before the exhaust manifold. Mine is mounted on the inboard edge of what was the propane locker side.
New fuel lines were run using the old ones as messengers. I replaced the aging propulsion engine lines as well, and used the opportunity to get the primary fuel filter in compliance with modern boating standards. Since the propulsion motor’s filter is inside the engine compartment, it’s supposed to have a metal flame shield around the plastic window… I bought a new Racor 500MA filter assembly and installed it over the muffler. The old Racor 500FG filter assembly was moved to a bulkhead in the aft cabin (out of the engine compartment) and became the generator’s primary fuel filter. I’ll cover it with a cabinet in a future project. Due to the long hose run, I added a 12v fuel boost pump (a Facet 40105) just after the primary filter, powered by the same circuit as the cooling fan. The secondary filter, a Racor 120 Series, is mounted in the lazarette, under the old propane lid.
The 12v cooling fan was installed high up in the lazarette on a backing plate epoxied into place. It exhausts out the clamshell vent that the propulsion motor used (I disconnected the engine vent hose).
The raw water strainer was mounted near the lazarette lid for easy access.
I reused the original generator 4 AWG cables that supplied 12v power to start and control it. It’s protected by an MRBF fuse at the house battery, but I also added a shutoff in the lazarette that I can see when working on the generator.
The Big Day
Finally, with the winter cover removed for spring, the big day to install the new unit arrived. The unit weighs 150 lbs. without the sound enclosure, which is too heavy for me to safely lift alone, but light enough that I can lift one end during positioning. I carefully slid the new generator from a scaffolding in my garage into the back of my car, then onto another scaffolding at the boatyard. I removed the starter to provide a lifting point on the unit for the halyard, and drained the fluids since I needed to significantly tip the whole unit during install. While Kristin cranked the halyard winch with our electric winch grinder I guided the generator up to deck level, then carefully aft along the deck. I set up a horizontal line through a block on the stern pulpit to another winch. Kristin cranked and eased lines a few inches at a time as I positioned the unit over the lazarette.
I knew it would be a tight fit getting the unit into position. I figured I’d have about one inch to spare, and I knew I couldn’t screw in the sound enclosure base to the isolation mounts until after the generator was inside the lazarette. If things didn’t work out, I could temporarily remove the generating end to shorten it a bunch. With a little muscle, I was able to lift one end of the generator so it would tilt and fit in the lazarette opening. Kristin made a bunch more adjustments to our lines as we eased the unit into place. We ended up with about a half inch to spare, but it fit, and no one got hurt! The final position adjustments, and lifting the enclosure up to make room for the isolation mounts, were made by me with a little muscle.
The access panel, which is only to be removed when installing or removing the generator, was reinstalled with 3M 4000UV and a bunch of bolts.
Next Gen includes a very simple control panel… basically just a start/stop switch and an hour meter. I moved these components to the old generator’s control panel mounted just forward of the primary electrical distribution panel in the cabin. I also reused the transfer switch as well as the voltmeter and ammeter that were already there. I added a 30A CB here, too, though there’s another one mounted on the unit. I also added a switch that controls the battery charger function of my Xantrex XC2000 inverter. Otherwise, the existing AC wires were reused.
Initial Startup
The brand new fuel lines were bled by shorting the wires for the remote- and unit-mounted boost pumps for a few minutes one at a time… otherwise it’s self bleeding.
After checking everything including oil, coolant, belts, and seacocks multiple times, I was ready to start it up for the first time. A few seconds of preheat on the glow plug, then switch to start… and it started right up!
After a few starts and stops for leak and belt checks, I began load testing it to see how the whole AC system worked with it. 3.5kW is almost 30A at 120V, and having an ammeter makes it easy to keep loads under 30A. I made a chart of how many amps each component of my AC system used: each battery charger, the hot water heater, microwave, toaster, and each air conditioner (6k and 16k BTUs). The hardest item to start is the 16k BTU Dometic forward air conditioner, but it can be done if the generator is lightly loaded first.
First Season of Use
Despite being a one cylinder diesel, it ran much smoother than I expected. Barely any vibration is noticeable inside the cabin. However, the exhaust sound was a little louder inside the boat than I had hoped. You can still carry on a normal conversation in the cabin, and it’s way quieter than running the propulsion engine, but being in the aft cabin is not peaceful. I never really intended to sleep with it running, though, due to carbon monoxide concerns. I hope I can improve the exhaust noise in the future… it may have to do with the shape of the lazarette, and how every surface back there reflects sound. Closing the aft cabin door helps quiet the main cabin significantly. Outside the boat, the exhaust sound is a little quieter than the propulsion motor. Noise (mostly the splash sound) is only slightly perceptible just a few boat lengths away… no lawn mower sounds coming from my boat!
The DC powered cooling fan is a little loud, too, though it’s only noticeable on the boat or within a boatlength of the stern. The pitch changes with battery voltage, especially when the battery charger switches to float stage. Some have suggested using an AC fan for quieter operation, so I may try this in the future.
The fuel boost pump, located in the propulsion motor compartment, is loud, too, but I think I can soundproof it pretty easily.
Since we have a bunch of charging capacity (110A combined) with our AC powered battery chargers, we can charge our house batteries super quick on days when it’s cloudy. During that time we can heat the hot water as well, which helps us make productive use of “generator time.”
This summer, Lake Michigan was unusually warm for both air and water temperatures. For several evenings at anchor the boat was quite hot, even well after sunset. Calm winds didn’t help get the heat out naturally, either. Instead of heading to a marina for shore power to run the air conditioning, we’d close the hatches and run the generator and air conditioning for about 90 minutes to cool the cabin enough for us to be comfortable. If one of us got hot in the middle of the night, we’d open the hatches at that point. In future years we may need to do a similar procedure for heat late in the season as well. Not exactly roughing it, are we?
One major objective of this project was to have good access for maintenance. A larger person may not fit in the compartment very well, but for me, working on the generator is pretty comfortable for a boat. Changing the oil at the end of the season was pretty straightforward. Other than the lost propane locker, we also gained storage space next to the sound enclosure.
While this project was a thorough test of my knowledge of marine electrical, plumbing, mechanical, and structural systems, it actually was a fun challenge! It wasn’t cheap… I spent almost $9500… but I saved a bunch of money by doing it myself, I know all the components of my generator system, and it’s set up the way I want.