Diesel generator just a bit too loud - how to quiet it down?

[NorthOrSouth]

1992 Monaco Dynasty DP with a Kohler genset (Yanmar 3 cyl diesel 1.4 liter engine - 9Kw)

This genset is huge in capacity, size and weight. IF we lived down south and needed to run the dual AC AND everything else inside I doubt we could overload the thing.

But the thing is, we live up north, boondock quite a bit and we rarely run more than one AC if at all. Fans and the powered roof vents do a good job most of the time and the AC on a really hot day.

The main thing is the genset is quite loud just because it's a big Yanmar in an open area under the front seats. I don't mind running it in a parking lot or on a street where we are not close to a house but its an issue in a national park or near homes. Its definitely not a Honda.

Is there any way to quiet down a big diesel genset like this? Its a permanent mount (no slide tray) up front and it needs lots of air flowing in and down to keep it cool but would it help to mount sound deadening insulation on either side? or maybe 6" below the bottom air exit? Maybe a bigger muffler?

The other option I'm leaning toward is taking it out altogether and putting in our yard as a backup for our home (9 kw should easily run the whole house) and putting in a much quieter Honda genset. I think 3Kw to 4Kw would suffice for 95% of what we do. I assume that would have to be a gas unit so we'd be carrying two fuels but I think the quieter atmosphere might make up for it. Or is there an option for a quiet diesel?

[NorthOrSouth]

Interesting. What's the name brand on that one?

[robertbenita]

Have you tried the coffee maker that works on propane. It is awesome and makes excellent coffee, as long as you put in the right amount of coffee grounds and water!

[NorthOrSouth]

Well at $80 its hard to go wrong... didn't think one of those would power a coffee maker but that's really the 'critical mission' for us. Anything else can wait til later in the day.

[Kayteg1]

Over the years I moved to camper and since we camp in Sierra where no AC is needed, for small coffee maker, microwave and charger I am carrying one of those $80 generators from Harbor Freight.
It does all we need, just not all at the same time and is easy to carry.
It is relatively quiet becouse it is small 2-cycle.
Making several cord pulls is a bit annoying as my Honda most of the time starts on 1st.

[NorthOrSouth]

I love the idea of solar smkettner, but the former owner just put in new batteries the week before we bought her. Unfortunately he just bought 2 regular 8D batteries for the house system instead of going for some quality deep cycles. I'd hate to toss them and start all over again to do it right or add another one or two 8D's when I know that's not the best way to go for solar. Probably jump on solar when these batteries are nearing their end.

Looks like carrying a little Honda genset is the best idea so far. At least then I know we can make coffee in the morning without the neighbors wanting to plug our muffler pipe with a potato 🙂

I see there are a ton of those cheap Chinese gensets doing the Honda lookalike thing in our local online ads. Don't suppose anyone has had a good experience with any particular brand? I'm guessing you don't get great quality or parts availability when you're buying a brand new inverter generator for $350?

jplante4: ONE cylinder? Holy cow, what's the size of that cylinder?

[Acampingwewillg]

We also have a similar type Gen set up( a PowerTech with a 3 cyclinder Isusu engine) not onn a sliding tray. It certainly is a tad louder that the Onan Quiet Diesel Gen's but whe your dealing with 10KW old diesel Gen, it's going to be louder than a gas inverter style. I do carry a 2000 watt inverter gen with me for those times I want relative quiet and keep the Residential fridge happy.

[jplante4]

Yeah, my standby genny at the S&B is 8.5 kW. Handles all the critical loads, and it's a single cylinder Yanmar. Can't imagine needing anything that size for a motor home.

[time2roll]

500+ watts of solar, couple more batteries and a 2000 watt inverter.
And leave the generator off unless you absolutely need the air conditioning.

[DSDP_Don]

"NorthorSounth"......You would need a 3000 Honda to run your A/C and that would be pushing it. I have two suggestions....first, buy a Honda 2000 and use it for everything, except running the A/C and then use the diesel unit when needed. The other would be to remove the diesel as you stated and then replace with a 4000 Honda or look for a used Onan diesel in a wrecked coach.

[NorthOrSouth]

That was what I was thinking of doing too. A 'suitcase' Honda or similar generator. Is a 2000 watt Honda enough to run an AC unit?

[Kayteg1]

There is no easy DIY way to quiet genset.
You can get it few % quieter by adding sound-absorbing mats into genset compartment, maybe couple less dB by getting upgraded muffler, but I bet lot of that noise comes from engine itself and I assume it is not inverter, meaning running constantly at 1200 rpm, or multiply.
I had the same issue with 3600W Generac, that even design for RV was noisily.
My solution was carrying Honda 3000EI in storage bay.
Not only drastic drop in noise, but also drastic drop in fuel consuption.