Generators. The Good, Bad and The Ugly

Probably getting time for compression test ?

Might clear up if it ran a good while at heavy load.

More frequent oil changes also help unused or too lightly loaded units.

FF said:

Probably getting time for compression test ?

Might clear up if it ran a good while at heavy load.

More frequent oil changes also help unused or too lightly loaded units.

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Never thought of that . It doesn't have much of a load at all . If I didn't use my roof top unit in the summer I could do without the generator all together .

Hair dryers and space heaters are a great way to load up a gennie. Around 1.5kW each, and cheap to buy.

Bay Pelican has a 8kw Westerbeke. We use two chargers (235 amps) and the water heater 750 watts to load her once a day during season. So far so good.

I'm with Art (#43 & 85) - '76 Kohler 6.5 - dare I say it? Gas. Ultra reliable, starts instantly, quiet, very little voltage drrop with load, runs everything on the boat with no strain. 1200 original hours, replaced the water pump due to small shaft leak a year or so ago. Plenty of parts still around. Reminds me that I need to run it - doesn't get used often except when we lose dirt house power during storms and evacuate to the boat and the AC.

sbu22 said:

I'm with Art (#43 & 85) - '76 Kohler 6.5 - dare I say it? Gas. Ultra reliable, starts instantly, quiet, very little voltage drrop with load, runs everything on the boat with no strain. 1200 original hours, replaced the water pump due to small shaft leak a year or so ago. Plenty of parts still around. Reminds me that I need to run it - doesn't get used often except when we lose dirt house power during storms and evacuate to the boat and the AC.

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sbu22 - Nice to hear success story from another gasser who also squarely faces TF's diesel brigade!

I calc we gasoline drinking Captains are out numbered by maybe more than 10x on TF. That's perfectly OK with me!

There are many pros and cons for diesel or gas propulsion in boats. I like em both.

Caltexflanc and Ski in N.C.:

I run (and own) a generator service shop and all I can say is "Hell Yes" to your advice to run the generator. It's almost "use it or lose it". We recommend a minimum of two hours at half load once per month. (two hours continuous, not half an hour four times) More is better.

The more you run it, the better it runs. Make it work. Get it hot - that dries out the windings, drives the moisture out of the lube oil, and puts some fresh fuel through the filter.

Keep the faith!

J.S.

back to FF and Art (# 70 & 71) - I use several Honda eu6500 gensets in my business. These work in industrial environments and are mostly running at max output. It is sometimes necessary to locate/operate them in more or less confined spaces (no, NOT OSHA confined spaces) that I think are very comparable if not more challenging environs than my engine room - close proximity to very hot vessels and piping, outdoors, lots of steam, etc. We have again and again cooled them with judicious use of a Kmart box fan or two , flex duct, and duct tape.

If my Kohler ever goes south, I will be replacing it with a Honda. 275#, 6.5 kw, $3500 NIB. I envision placing it in a box (the current Kohler is freestanding in the ER - not enough noise to warrant soundproofing - the Honda is amazingly quiet) with push/pull fans interlocked with the ON/OFF. Not sure I see the need to "marinize" anything.

SBU:

Actually, I agree with you. While I've never put one on a boat, I have a ton of customers using those portable Honda inverter-type generators on RVs, mobile food concession trucks and two on mobile dot-and-cat grooming trucks (seriously! I'm not making this up. There really are people in Boston who will pay for a professional to come to their home to give their pets haircuts and shampoo them.)

One advantage to the Honda idea is that if it ever gives you trouble, you just yank 'er out and drop it off at your friendly neighborhood generator shop. In extreme cases, just drop it over the side and get another one.

Cheers!

J.S.

A buddy had a Honda 2000, I think that was the rating, used it on a huge pontoon boat to do local cruises and run chargers, stereos, blenders, lights, etc. One day some knucklehead crew slipped while moving it around and it went overboard and submerged. He was able to snatch it right out with a line that was around the handle so it was only under water for a matter of seconds. They soaked it with wd40, let it dry a bit in the sun, and it cranked right up. They ran the thing for another couple of years, then I think someone stole it.

Nice little machines, those Hondas. In fact I can't think of any turds Honda has made regarding gasoline engines. Their stuff just plain works.

That's the other thing - I'm actually unsure of the hours on these units, don't think any have exceeded 1K yet - but other than oil changes and cleaning the air filter, we start them up and run them. Period.

We are using a Honda EU1000i on deck for battery charging, vacuuming, and heating when necessary. It's main use is topping up the batteries in the evening and morning while at anchor and/or on docks with no power. We have a home made pad to set the Honda on to absorb the vibration, or I pull the inflatable alongside and put it in there. It uses little gas, starts on the first pull, and does not take up much space.

For those inboard installations - is it possible or common to run a coolant loop (fresh side) from the generator through the hot water heater, like many of our main engines are plumbed?

My thoughts are that you could run a bit smaller generator capacity that way, and use that engine heat instead of AC for the domestic hot water.

sbu22 said:

back to FF and Art (# 70 & 71) - I use several Honda eu6500 gensets in my business. These work in industrial environments and are mostly running at max output. It is sometimes necessary to locate/operate them in more or less confined spaces (no, NOT OSHA confined spaces) that I think are very comparable if not more challenging environs than my engine room - close proximity to very hot vessels and piping, outdoors, lots of steam, etc. We have again and again cooled them with judicious use of a Kmart box fan or two , flex duct, and duct tape.

If my Kohler ever goes south, I will be replacing it with a Honda. 275#, 6.5 kw, $3500 NIB. I envision placing it in a box (the current Kohler is freestanding in the ER - not enough noise to warrant soundproofing - the Honda is amazingly quiet) with push/pull fans interlocked with the ON/OFF. Not sure I see the need to "marinize" anything.

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I agree that the efficient Kohler 7.5 is quite quiet; I also do not have sound box. Thanks for tip on the "what if" replacement gen set. Wow... you put 6.5 kw Honda in a box... don't forget to turn it off when leaving the boat!

Enclosure would be a better word. Want the ability to supply sufficient and controllable cooling air flow to the unit. Noise just isn't a concern with the 6.5 Hondas.

sbu22 said:

Enclosure would be a better word. Want the ability to supply sufficient and controllable cooling air flow to the unit. Noise just isn't a concern with the 6.5 Hondas.

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'
"Enclosure" Just so damn PC! - LOL

"For those inboard installations - is it possible or common to run a coolant loop (fresh side) from the generator through the hot water heater, like many of our main engines are plumbed?"

Yes ,some folks only plumb in the noisemaker and not the main engine,as it may be on longer.

BUT if the noisemaker is small it can heat domestic hot water , but probably not be used to heat the vessel.

Using the noisemaker coolant for HW relieves a 1500W load from the unit , to use for other purposes or simply to spec a smaller unit.

Aft in the dink is an old trick for charter sail boats in the Carib.

No noise , no stench (for the charter party , the rest of the anchorage gets the noise and stink) and loads of juice!

FF said:

"

Aft in the dink is an old trick for charter sail boats in the Carib.

No noise , no stench (for the charter party , the rest of the anchorage gets the noise and stink) and loads of juice!

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And no carbon monoxide either.

FF said:

"For those inboard installations - is it possible or common to run a coolant loop (fresh side) from the generator through the hot water heater, like many of our main engines are plumbed?"

Yes ,some folks only plumb in the noisemaker and not the main engine,as it may be on longer.

BUT if the noisemaker is small it can heat domestic hot water , but probably not be used to heat the vessel.

Using the noisemaker coolant for HW relieves a 1500W load from the unit , to use for other purposes or simply to spec a smaller unit.

Aft in the dink is an old trick for charter sail boats in the Carib.

No noise , no stench (for the charter party , the rest of the anchorage gets the noise and stink) and loads of juice!

Click to expand...

Gennies don't make much heat, so not real practical to use its coolant to heat water. Also will tend to overcool the gennie, which is not good for it.

The whole point of using the main engine to heat water and/or cabin is to avoid needing to run the gennie much at all. The main engine provides heat and DC power to inverter for modest AC loads. In my case while cruising, gen might run an hour or so in the early am, an hour or so before bed, that's it.

Also, it's good for a gennie to run loaded. Water heater is a good tool for that.

Ski in NC said:

In my case while cruising, gen might run an hour or so in the early am, an hour or so before bed, that's it.

Also, it's good for a gennie to run loaded. Water heater is a good tool for that.

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Agreed on run time and practiced on load (i.e. hot water, fridge, batts' charge, communication devices charge, stove/oven... etc.

I could never understand why persons sometimes run gen set for next to no reason. Why not take care of needed items all at once?

Saves on fuel, best to elongate gen's life span, keeps down the noise, limits exhaust

"I could never understand why persons sometimes run gen set for next to no reason. Why not take care of needed items all at once?
Saves on fuel, best to elongate gen's life span, keeps down the noise, limits exhaust"

To be efficient a large good (expensive) inverter and large batt (expensive) bank are required, and planning.

For many just throwing the noisemaker on is easier , and even badly underloaded most will run 3,000- 4,000 hours , a long time with a 200 hour a year boat.

I considered using the genset cooling system to heat water. Decided against it as it would mean I was totally dependent on the genset for hot water. When the genset is working I can heat water electrically. If the genset is down, I can use the main engine. With a combination of solar panels, wind generator and our auxiliary engines alternator we can charge the batteries so we have reasonable backups if the genset goes down.

"Gennies don't make much heat, so not real practical to use its coolant to heat water."

Many buried noisemakers have diesel engines that usually put 1/3 of the diesel energy into the coolant.

At 1/2 GPH , with about 150,000 BTU in a gal of diesel ,,that would be 25,000 BTU for the hot water tank.

15A /120V is perhaps 5000 BTU so there is considerable energy to shorten the noisemaker ON time if desired .

If over cooling is a problem , as it usually is with a keel cooler, a similar bypass thermostat can be installed to keep the return water 150-160F.

That ignores the flow rates and heat transfer characteristics of a water heater loop tied to the gennie. Only a fraction of the heat generated will get transferred to the water tank. You would need more than the typical half inch hoses and a big HX to make full use of the heat. Also, many gennies do not have convenient coolant taps for tstat bypass coolant flow like mains tend to have.

Also, a gennie makes very little heat when it is off. The main engine has to run to move the boat.

I think the consensus is it is more practical to plumb water and cabin heat off the main.

At slow cruise of 950 rpm, my cabin heater can sub cool the main engine. You feel the heat getting weak and coolant temp drops. Granted, it is a pretty big HX used for cabin heat.

CaptTom said:

Same genset, 1980 vintage, same experience. To that I'll add:

Outside the boat, no-one even knows it's running. Inside, it'll rattle your teeth right out of your head. The sound shield is old and not very tight, so I'm not convinced it's helping much. My problems so far have been with the raw water system, hopefully I've got them all addressed now.

I'm not ready to invest in a Northern Lights. If you find a used boat with one of those installed, that would be a huge plus. I will bring a Honda 2000i on longer trips as a backup, and try to keep the Onan alive for as long as I can.

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I think a Honda 2000i is just what we need, not having the room or need at this point for something larger.
But how is it connected to the boat. I don't see how you can charge the house bank. I admit electrical issues are not my strong suit.

Slowboat 37 said:

I think a Honda 2000i is just what we need, not having the room or need at this point for something larger.
But how is it connected to the boat. I don't see how you can charge the house bank. I admit electrical issues are not my strong suit.

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Just plug your shore-tie in to the Honda, and your on-board charger will do its job.

Before you move forward, you may wish to look up the consumption of your battery charger and ensure it does not exceed the output of the Honda. You should find this in your charger manual, or check online for a manual.

Our charger is fairly small and our Honda EU 1000i is able to power it. I would expect you have a larger charger than mine.

Please send me a PM if you desire direct assistance.

"That ignores the flow rates and heat transfer characteristics of a water heater loop tied to the gennie. Only a fraction of the heat generated will get transferred to the water tank."

RIGHT!, the noisemaker will heat domestic water at the same speed as the main engine.

Then the question becomes which gets the most hours during the usual cruise,

And can the noisemaker do something useful with the 15A not required to heat water.