advise on genset

[Dusky Sound]

Looking at adding a genset 5KW to 7KW
Currently have 3KW inverter
Have looked at Northern Lights, Onan, Kohler, Mase
Any recommendations or suggestions.
yacht is 50 foot steel motorsailer

[truant]

Check out Nextgen. We have a 5.5 kw in a nice fiberglass enclosure. They're made in Jacksonville, Fl, use a Kubota engine, are compact, and run at medium rpm's.

[David M]

There is also Volvo, Panda, Westerbeke, Universal and Mastervolt. I am not necessarily recommending them, just adding to your list. I think that's pretty much all of the more common brands.

With your selection it is also important to consider parts availability, delivery speed and the price of parts to where you will be cruising.

[djmarchand]

In a 50' motorsailer weight and space may not be big issues. In that case I would choose a heavy 1,800 rpm genset. The Northern Lights is a rock solid example of these.

[Dusky Sound]

yacht is New Zealand registered.
Plan to spend time Australia and Pacific
Like the idea of 1500 rpm
Any thoughts appreciated

[CarlF]

I am familiar with Onan (and very happy) but there are several good brands.

All manufacturer's 1500/1800 RPM units are considerably quieter.

Consider planned location of genset and access to maintenance items. The Onan, for example, puts everything you need to reach on the same side.

Will you have air conditioning? Air conditioner start loads are about twice the running load. You may need one size up to avoid popping breakers.

Gensets should not be run for for long periods at less than 25% load or more than 75% load. Below 25% they are also fuel inefficient.

Consider mechanic familiarity as well as parts supply. You never want a mechanic "learning" on your genset. The Onans are very common worldwide.

Carl

[downunder]

Would be useful to know what your loads would.

Northern lights, Onan, Westerbake are all good makes. I have noted numerous problems with the higher reving (3000rpm) sets such as Panda.

Sounds as if your are going for a smaller genset to run at 75-80% load for best engine life. The Vitron inverter charger with boost will help with a smaller genset and allow for higher electric motor starting currents.

Ensure it is low rev 1500/1800 - heavier but much more reliable.

[osirissail]

Check out Beta Marine NC - Beta Marine US Ltd. Distributors for Kubota based marine They have gensets also using the Kubota engine. I have had mine for 6 years and it is a very low maintenance and economical unit.

[Dockhead]

Originally Posted by downunder

Would be useful to know what your loads would.

Northern lights, Onan, Westerbake are all good makes. I have noted numerous problems with the higher reving (3000rpm) sets such as Panda.

Sounds as if your are going for a smaller genset to run at 75-80% load for best engine life. The Vitron inverter charger with boost will help with a smaller genset and allow for higher electric motor starting currents.

Ensure it is low rev 1500/1800 - heavier but much more reliable.

+1

If you can possibly fit it in your boat, definitely go with a 1500/1800 RPM genset -- the difference is night and day.

Northern Lights, Onan, and Kohler are all very good. They are simple, heavy, large displacement, low-revving. As a result they are much quieter and much longer-lived and much more reliable. Go for a three-cylinder over a two-cylinder if you can -- the sound and vibration is more pleasant and less intrusive.

Avoid Fischer-Panda like the plague. It's the opposite approach -- a tiny, small displacement engine screaming away at high revs inside a sound enclosure.

We have a 6.5kW Kohler on our boat. It has a 1,000cc three-cylinder Yanmar diesel engine and is almost inaudible inside its own sound enclosure inside our sound-proofed engine room. We don't have air conditioning (yet), but I would not hesitate to run the Kohler all night on a hot night to run air conditioning; you don't hear the genset and neighboring boat in the anchorage hear absolutely nothing.

When sizing your genset, consider using an inverter with "power boost" feature, like the Victrons. That way you don't have to size the genset for your startup loads (which can be very big if you have a lot of air conditioning). You can size the genset for the continuous loads, and the power boost will supply the short-term startup loads using inverted battery power. You don't want your genset to be oversized, because:

1. It will be needlessly more expensive;
2. It will be needlessly larger, bulkier and heavier;
3. It will usually run with less load than it needs to be happy and healthy
4. It will usually run with less load than it needs for best efficiency

[btrayfors]

+1 on Northern Lights genset. If you have the room, go for it.

I have a NextGen 3.5kw. Like it, but if I had the room I'd certainly go for the Northern Lights...very reliable.

Bill

[DotDun]

I have the Mase IS 7.6. I bought it due to the intercooler which equates to no need for additional ventilation. When I was looking, other brands were requiring an additional blower in the space.

It's been very reliable but only have ~500 hours on it.

[CarlF]

While I like Northern Lights very much, they are strongest in the US. I'm not sure it's the best choice for the South Pacific. Northern Lights lists one dealer in all of New Zealand -- Onan has a dozen.

The Victron Inverters are a great way handle the starting surge on an air conditioner and allow a smaller genset. A few years ago they did an astonishingly detailed "Marine Generator Test". You can download the report from their web site.

White papers - Victron Energy

Carl

[hanschristian38]

Very interesting thread -

We bought a boat last year with a dead genset on it. It seems that the 8Kw Westerbeke generator was used to charge the batteries through a relatively small battery charger. The generator was not used hard enough and died after only 1100 hours of use. There was no compression in any of the three cylinders and the crankcase was full of diesel fuel. I had the generator removed and am now looking at smaller gensets to replace the Westerbeke.

Thanks for the input from the forum.

[downunder]

Originally Posted by hanschristian38

Very interesting thread -

We bought a boat last year with a dead genset on it. It seems that the 8Kw Westerbeke generator was used to charge the batteries through a relatively small battery charger. The generator was not used hard enough and died after only 1100 hours of use. There was no compression in any of the three cylinders and the crankcase was full of diesel fuel. I had the generator removed and am now looking at smaller gensets to replace the Westerbeke.

Thanks for the input from the forum.

A very good example of an oversised and underloaded genset. thanks

[barnakiel]

I used a big Onan and it was the best genset I have ever seen. If small Onans are like their bigger brother I would not hesitate to use one. Somehow, I have never seen a small one.

The bad apples I have used were:
- Panda,
- Westerbeke,
- Yanmar.

Honda gas was great too.

Panda was actually half-bad: good when it was OK but then hell to fix once failed.

b.