There are many questions when it comes to selecting a marine generator: how many kilowatts would be enough to power all necessary appliances, should you go with a gas or diesel powered gen set, and one of the most important: which brand makes the best marine generators?
With decades of collective boating experience under our belt, as well as training and experience gleaned from many years of sales and support of marine generators from the major brands, we hope to provide some direction when it comes to selecting your own.
Our best marine generator guide will help you better understand the similarities, and well as the unique characteristics, advantages, and disadvantages of all the major marine generator brands and their gen sets – Cummins Onan, Kohler, Phasor, Northern Lights, Westerbeke, Fischer Panda, VTE Paguro – our personal recommendations, the advantages of diesel over gas (and when gas is important) in gen sets, and how to make the most out of the generator you decide on.
The Importance Of Having a Marine Generator Onboard
Many of our boats are filled with electricity-consuming appliances: A/C systems, refrigerators, water heaters, and navigation devices, just to name a few.
Supplying the necessary power for all these accessories can be a challenge when out at sea or when far from shore power.
One – impractical – option we have is to keep the main engines running to power all these electronics, but this is not ideal due to the noise, vibration, fumes and fuel consumption.
A good marine generator will provide the better, quieter and energy-efficient powering solution you need for all of your onboard electrical needs.
The Truth – Most Generators from Major Brands Will Serve You Well If Properly Taken Care Of
At the end of the day, virtually all marine generator manufacturers outsource their blocks (Kubota, Mitsubishi, Shibaura) and many use the same hot ends too. Main differences from one generator brand to the other are in marinization and control circuitry.
Most diesel 1800 / 1500 rpm gen sets from the major brands are capable of lasting you anywhere from 15 to 50 thousand hours with clean fuel, proper maintenance and regular use. Following these guidelines, you should be able to get the most out of any gen set from the top brands:
- Generators like to be run. The marine environment is harsh on unused engines. You will have fewer problems if you use them regularly than if you let them sit and rust. Start them up no a scheduled basis, even if not using them.
- Keep your generator DRY. Sea water dripping from the cockpit deck will wreak havoc on even the best marine generators. We’ve heard reports from boaters with “cheap” models who’ve gotten 10+ years out of their gen set and no issues ever starting up, thanks to keeping their bilge dry the entire time.
- Perform regular maintenance per the operators manual… change oil, filters, impellers, per schedule.
- Winterize your gen set if living in a cold climate. A generator’s engine is no different to winterize than your main engine. Perform your fluid / filter service, and make sure the block is filled with antifreeze.
- Size your generator properly. Add all of the pulling amperage from your main appliances and equipment, for example, 85 amps. Multiply it by voltage, example, 115V. In this example, that would be 9,775 watts. Round it up to the next 1,000, in this case would be 10,000 watts and add a 20% safety margin. We’re at 12,000 watts, or 12 kilowatts. You would need a 12 kW generator in this case. (If you’d like some help figuring out what size generator you need, don’t hesitate to contact us or chat with us below).
After knowing this, you’ll see that when it comes to gen sets, the “which is the best marine generator?” conversation then becomes much like the discussion on whether Ford is better than Chevy. It is, however, recommended in most cases that you go with the lower revving (1800 or 1500 rpm) engines, as they are quieter, more efficient, and last longer than the faster revving 3600 / 3000 rpm engine models some brands use.
That being said, there still are some definite advantages and disadvantage to each brand worth noting.
Cummins Onan has been in the diesel engine and power generation industries since 1920. Both Cummins and Onan started out separately around the same time, with Cummins developing diesel engines. Onan made small electrical generators, but soon went on to develop stronger gas-powered units, and was one of the first US companies to design and build small diesel generators.
Cummins purchased majority ownership of Onan in ’86, assuming total ownership in 1992, bringing together the technology, knowledge and expertise of both companies. Cummins diesel engines come standard as the diesel option in many Ford, Dodge and Nissan pickup trucks, and their marine generators come from factory in Viking, Hatteras and Sea Ray yachts. Onan gen sets use a 3 cylinder Kubota engine, one of the best small diesels available.
With proper maintenance, an Onan generator is considered to be just about bullet proof, making it a necessary mention in our best marine generator guide. Easy to start up, runs well at high temperatures, and is quiet. Excellent generator ends, and easy-to-troubleshoot should something go wrong, with 24/7 emergency service and a large global support network.
Some complaints as to Onan generators are with the computer control system, similar to the Kohlers. Some feel it is unnecessary, and have experienced an inability to do field repairs on the computer control system itself. Many find the computerized control system to be reliable though. Replacement parts are generally not cheap.
Kohler Marine Generators
Kohler, a US manufacturing giant around since 1873, is known for making quality products across several product lines. Kohler was the first company to ever offer residential back-up generators in 1920.
When it comes to their marine generators, Kohler is constantly working to produce a smaller, lighter gen set with a smaller footprint, all the while delivering substantial power. Kohler marine generators come from factory in a lot of larger yachts such as Azimut, and have an excellent service history.
Some points on Kohler marine generators:
- Kohlers use Lombardini (acquired by Kohler) or KDI (built in-house, pictured above) engines, both strong marinized engines.
- New models come encased in a combination of sound-deadening foams and rigid barriers which results in a very quiet unit with low vibration.
- Kohler is the most affordable of the brands, including low cost replacement parts.
For some boaters, a downside to the Kohler is that it is too “electronic”, with many circuit boards, engine control, many diodes in the circuits, and is run by a computer program rather than just a simple machine like others generators. They are also packed in pretty tight, which can make some repairs hard to get to.
Phasor Marine Generators are manufactured in Pompano Beach, Florida, with Phasor specializing in heat-exchanged cooled marine applications for over 3 decades now.
All Phasor generators are EPA compliant, and use Kubota (same as Cummins Onan) or John Deere based 1800 RPM engines, with gen sets ranging from 4kW to 99kW.
Phasor makes our best marine generators list because they are easy-to-maintain, with no major electrical components, and a wide availability of replacement parts. Only temperature, water exhaust, flow, oil pressure sensors. 10% lighter than Kohler or Onan gen sets, and 20% lighter than Northern Lights. Quick lead times from the manufacturer as well.
Occasional complaints of issues with transmission, which are covered by Phasor’s 5-year warranty. Some noise complaints depending on where generator is installed. Sound enclosures are available should this be an issue.
Northern Lights has enjoyed a strong reputation in the marine market for a long time now thanks to their solid, durable marine generators.
Originally based out of Alaska in the the 1960s (hence the name), Northern Lights had contracts with the State of Alaska for providing electricity to rural schools and villages and powering of communication centers along the Alaska Pipeline, later entering the marine market in the 80s.
Powered by a Shibaura engine (Japanese mini tractor engine manufacturer), with an in-house lugger marinization process, Northern Lights generators use a simple and logical control system, and are easy to repair and get parts for in the sake of any issues. With more machinery than electronics, Northern Lights is a favorite among many boaters.
While not cheap, you will get what you paid for in terms of durability, ease of maintenance, and good generator ends.
However, along with the high price tag on the unit, replacement parts can be costly. Raw water pumps and issues with a rusting exhaust (not made of stainless steel; can lead to saltwater entering / damaging generator) are some common issues. Stainless steel replacement exhaust manifolds are no longer available. Northern Lights generators larger / heavier than most other brands, so engine room space needs to be taken into consideration.
Westerbeke, founded in 1937 in Avon, Massachusetts, was the first company on this list to enter the marine diesel engine industry with the Detroit Diesel 6-71 in 1938.
Westerbeke gen sets have a long and storied history of being used in large maritime companies and governmental agencies such as the US Navy and Department of Homeland Security, and come standard in many powerboats & sailboats.
Westerbeke marine generators are quiet, and built with solid Mitsubishi engines. One of the only brands to offer gas generators a this time, Westerbeke uses Tohatsu engines for their gas gen sets.
The Westerbeke has a mechanical governor and throttle control, which can make problems easy to diagnose at sea and keep running.
While Westerbeke marine generators have earned their place in our best marine generator guide, being well-designed, reliable and enjoying a solid reputation, there are some complaints about quality of generator ends, belt drive, and issues with salt clogging the cooling system. Maintenance and replacement parts can be costly as well.
Fischer Panda started out making water-cooled diesel generators in Germany in 1988, initially working with BMW’s Marine Division. They entered the US market with their Fort Lauderdale location in 1995. Fischer Pandas come standard in Marlow Hunter and Pursuit Yachts, as well several Boston Whaler models.
Fischer Pandas are the lightest and smallest of the marine generator brands listed here, good for fitting into smaller engine rooms. They produce significant power from their Kubota or Farymann diesel engines. They are freshwater-cooled, and come automatic with a sound shield, due to their compact suitcase design.
Fischer Panda marine generators have the downside of being 3000 / 3600 RPM, which can lead to them wearing out quicker. This also means that there are more maintenance requirements, more oil changes needed, etc. being that it runs at twice the revolutions. However, for a 3000 / 3600 RPM / 2 cylinder unit they are considered quiet, with lower decibels than some of their 1500 / 1800 RPM counterparts.
The Fischer Panda has a somewhat complex design that, when working is great, but when not, can be difficult to diagnose and repair in some cases. Maintenance requirements can be demanding for some, leading to issues if neglected.
That being said, Fischer Panda has excellent customer support, known to really go above and beyond for their customers. You’ll find many satisfied Fischer Panda customers, and boatbuilders decided on using Fischer Panda generators in their boats for a reason.
A direct, but-less expensive, competitor to Fischer Panda, Paguro marine generators are manufactured by Volpi Tecno Energia (VTE), an Italian-based manufacturer who’s been producing electrical equipment for the marine and boatbuilding industries since 1933.
Known as one of the quieter marine gen sets, all Paguro generators are 1800 RPM and come from factory with a sound enclosure. Simple and compact, but powerful, Paguro gen sets run off of Lombardini engines, the same engines used in Kohler generators. Paguro generators have an internal heat exchange with coolant.
Some problems with vibration leading to chafing of hoses and cables have been reported, generally when not installed tightly or onto a solid, even surface. 2 year warranty from VTE.
We’ve Selected Cummins Onan and Kohler As The Best Marine Generators – Here’s Why
If properly taken care of, following the maintenance schedule and staying on top of any issues, you should be able to get tens of thousands of hours from any one of these brands. Each brand has many reports from satisfied customers experiencing excellent, long-lasting performance.
But in our experience, when it comes to reputation, durability, severity of issues you may face, cost to repair these issues and quality of product support provided by the manufacturer, we feel strongest about recommending Cummins Onan and Kohler as the best marine generators, with Onan having a slight edge due to performance.
If cost is a consideration, Kohler is your brand. A powerful, yet quiet machine in an affordable package. Affordable replacement parts and repairs if needed, excellent customer support, and most importantly, a Kohler marine generator will provide you with the reliable power you need onboard.
Cummins Onan has a slightly higher price point, and generally more costly replacement parts, but you’ll get what you paid for with a powerful, rock-solid marine generator that “runs like a sewing machine” as one boater once put it – flawless startup, very little maintenance requirements, and top-notch customer support.
Honorable Mentions: I’ve been very impressed with Phasor and VTE Paguro lately, not only due to their design quality and ease of maintenance, as well as positive feedback we’ve received from customers, but because of their companies’ support and quick turnaround times. They are both excellent alternatives for marine generators to some of the more well-known brands out there.
20 Most Popular Marine Generators in 2022
Being one of the top marine generator retailers in the US, I’ve tallied the inquiries into different generators as well as analyzed our Google Analytics data in order to see which generators were most inquired about + searched. This gives us a pretty good idea as to which were some of the most popular marine generators this past year, at least according to our information:
- Kohler 5EKD – 5KW Gas Marine Generator, 60HZ, 120V, 1-PH, H/E
- Phasor LP1 – 3.5 KW, Kubota Engine
- Cummins Onan 5 kW (MDKBH), 60 Hz, 1 phase, 120V, 2900 RPM
- VTE Paguro 5000 – 4 KW – 3600 RPM, 60 Hz Marine Generator
- Kohler 40EKOZD – 40kW 60 Hz, 120V, 12VDC, Diesel fueled
- Westerbeke 5.0 MCGA – 5.0kw, 60 Hz Low-Co Gas Generator
- Next Gen 3.5 KW Marine Diesel Generator, 1800 RPM W/ Sound Shield
- Phasor K3-6.5kw Diesel – 6.5 KW -1800 RPM – Compact Series
- Cummins Onan MDKBJ 7.5 KW Marine Generator, 60 HZ
- Kohler 24EKOZD – 24KW Diesel-Fueled, 60hz, 120v, Heat Exchanged
- VTE Paguro 6000 – 5.5 KW, 60 Hz
- Fischer Panda Generator – 5kW, 60 Hz, 240V/120V, 40 Amps
- Westerbeke 7.5 MCGA – 7.5kW Marine Generator, 120/240 Volts, 13.2 HP, 3 Cylinder, 4 Cycle
- MasPower MP6M 6KW 1800 RPM Marine Diesel Generator
- Kohler 7.5EKD – 7.5KW, Gas Fueled, 60hz, 120v, 1-Phase, Heat Exchanged
- Cummins Onan MDKDK 9kw, 60 Hz
- Kohler 9EKOZD – 9kW 60 Hz, 1 Phase, 120V, 12VDC, Heat Exchanged
- Cummins Onan MDKDM – 11.5 kW, 60 Hz, 1 phase, 120V, 1800 RPM
- VTE Paguro 4000 – 3.2 KW – 3600 RPM
- Phasor k3-9.5kw Diesel Marine Generator – 1800 RPM
Should You Purchase a Gas or Diesel Marine Generator? Which is Better and Why?
The vast majority of marine generators either run on gasoline or diesel fuel, with diesel quickly becoming the norm for most brands.
In most instances, a diesel-powered boat will carry a marine diesel generator, and a gas-powered boat, a gas generator. This is out of convenience, as it will run off of the main fuel line, and won’t require separate fuel tanks.
Most boats 26′ and longer come equipped with diesel engines standard, with diesel fuel having several advantages over gas:
- Cheaper / more efficient
- More environmentally-friendly,
- More efficient
Diesel technology in marine generators has come a long way in the last decade or so, with the aim of taking advantage of these benefits. With a lower fuel consumption rate you can keep your appliances powered for longer journeys, as well as take less fuel with you, decreasing the weight of your vessel.
However, there are some instances where gas would be preferred. If your boat comes standard with gasoline engines, and you are not going to far from shore, gas may be the more convenient choice. Westerbeke’s fuel-injected low-CO gasoline generators have been engineered to significantly reduce carbon monoxide emissions, and have come a long way in stretching the efficiency of gas for their gas generators.
Diesel generators can be used on gas boats. Requirements for this would be a separate diesel tank, and you need to ensure that the diesel generator is ignition-protected.
Need A Marine Generator? We Can Help
If you’d like to discuss further which would be the best marine generator for your particular needs (technical or economical), or if looking to purchase a marine generator, please don’t hesitate to chat with us below, contact us here or give us a call at 1 (800) 766-5256.
Have a good one!
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Doral, FL 33172
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I am looking at 2008 33 Back Cove with a fisher Panda 4kw generator. I have read lot bad issues with these and long history of problems.
What about 4kw fisher, should I be concerned?
In my research, from what I’ve seen is while they may get a bad rap from many, they are actually pretty solid generators, with their own strong “following”. Should you be concerned, though, your best bet is getting a local specialist to take a look at it. Or try to talk them down on price based on it’s rep…
Just extracted a fisher Panda mini 8 from my regulator 41. The best use I could think of for it is as an anchor.
It only has around 200 hours. Nothing but trouble.
Been in the marine industry for over 40 years.
The boat enters fishing tournaments from New Jersey to Palm Beach.
Thanks for the feedback, Richard. Good to hear everyone’s experiences on these brands. Thanks