ONAN 7.5kW DIESEL ....Opinions?

[Stormcloud]

Hi:
Locally (almost) for sale is an Onan 7.5kW 'Commercial' diesel generator with 2250 hours on it.
It has a 3 cyl Kubota engine powering it.

It is not the Quiet Diesel type....
here's a photo.


Any experience with these? What do I look for when checking it over?

Thanks!

Mark

[cody]

Mark, you'll need my address for sending it lol.

[gumpy]

Mark,

How much are they asking for that unit?

I don't know a lot about the commercial units. I would determine how loud it is, for starters. Then see if they have records on maintenance (oil change, air filter, etc).
2250 hours doesn't seem like a lot, but then again that's more than a year running 8 hours a day, 5 days a week.

I only put about 40 on  mine last year.  I have the Quiet Diesel 7.5kw model which also has the Kubota in it. I like it, so far.

[Stormcloud]

Asking price is $2600 CDN.....thats like $19.95 usd....

[cody]

Somehow I saw that coming lol.

[gus]

I think you will find out that $2600CDN is about the same as $2600US now, but it is still not a bad price!!

[Stormcloud]

I agree, $2600 seems like a reasonable deal, if it checks out OK. A 3 cyl Kubota should be good for lots more hours.

I would remote mount the rad and install an electric fan on it.I could muffle it a couple times to make it quieter, and maybe a quiet box for the mechanical stuff.

Its been for sale for at least a couple months, and the price has dropped. Maybe not a big market around here?

I will likely call tomorrow and find out more.

[robertglines1]

go for 1500---

[Stormcloud]

Im kinda thinking that too......its "$2600 OBO".....I may have an 3000w inverter gennie with only a few hours on it to sell if this one checks out.

[robertglines1]

I just pd 1500 for a 7.5 with 34 hrs on it..its not apples to apples is a gas unit but is a rv unit in soundproof box..I think the one your looking at is better...the seller started at 2600$

[Ncbob]

Mark, as an old retired Onan dealer here's my opinion:

Onan built a DKC (4 KW) and a DKD 7.5 or 8KW some year ago and they were reliable little generators.

Of course, like with anything used, it's worth is only as good as the maintanence it's had. They were not loaded down with a bunch of solid state boards only the voltaage regulator as far as I can recall. Please remember I retired some years ago.

THe Kubota engine is reliable and the generator end was built in MN. As I always advise, clean oil, clean coolant, clean air and clean fuel will make the worst generator the best investment you'll ever make.

Best,

NCbob

[TomC]

Just to show you how long that 3 cylinder Kubota can last, I have a friend that had a Powertech 7.5kw with the same 3 cylinder.  When he sold the truck, it has over 23,000 hours on it.  So 2,300 hours is like 92,000 miles.  Considering a new unit is around $6,000, that looks like a good price.  You can remote mount the radiator with an electric fan (talk to Dick Wright at Wrico International) to make it really quiet.  Good Luck, TomC

[JohnEd]

Integrate the cooling into the engine cooling system and then install a simple thermo controlled elect fan on the big rad.  All done!

John

[TomC]

Unless you have a really BIG radiator, of which most buses do not, I would suggest you not run both engines with one radiator.  On a big rig truck, this isn't much of an issue, but with a bus, most buses have marginal cooling to start with, let alone adding another 15hp engine to the strain.  Plus-like what has happened to us, if you have a problem with the main engine, you still have the generator's radiator to run the generator while you fix the big engine-nothing like having air conditioning running on a hot day to take a break in the nice, cool insides.  Good Luck, TomC

[JohnEd]

Unless you have a really BIG radiator, of which most buses do not, I would suggest you not run both engines with one radiator.  On a big rig truck, this isn't much of an issue, but with a bus, most buses have marginal cooling to start with, let alone adding another 15hp engine to the strain.  Plus-like what has happened to us, if you have a problem with the main engine, you still have the generator's radiator to run the generator while you fix the big engine-nothing like having air conditioning running on a hot day to take a break in the nice, cool insides.  Good Luck, TomC

With 300 HP pushing, a 15 HP genny would bump the load by 5%.  If that causes you a problem you have others that are more pressing.  You need to move a lot more air thru a proper sized rad for the genny than you do for the massive engine rad and that makes the one ever so much quieter.

Tom is right though.  Many have the Hydronics and hot water tank exchanger and genny all hooked into the engine coolant system.  They use isolating valves..to be sure.  It is design choice.   A lot of pluses and compromises and counter points.   You are going to be faced with a lot of that.

John