Will, if you give me the machines ID info off the label I can look up the boards part number and tell you the cost.

I can get you one. Have it drop shipped direct to you and you can use a CC for payment.

Model info is on 2 labels. 1 Up by switch and 2 down along the front lower area.


If you power the fuel pump externally, the board is still in control of the engine and everything else.
It powers a solenoid on the fuel rack on Isuzu engines and that's usually what an older 12.5 has for an engine

Low oil pressure, hi water temp and voltage issues will still cause a machine shutdown.

The pumps are lo pressure and the fuel will just return back to the tank with the engine not running and the pump on....

This message has been edited. Last edited by: SCDIV1,

The numbers on the tags are:

G060946533

12.5HDKCB11506B

I'm thinking I may work on a bypass steup, relays with a manual switch also. I want it to be as normal as I can to control from inside, I think i can achieve that with relays and then maybe have an addition toggle switch in case even the relay fails.

If you could get me a price, in case I decide to g o that route.. that would be helpful.

PM sent Will

Helping a friend with a late model 7 K onan with emissions…. Already contacted SC on this one.. ugh.

Welcome to my world Barry.....LOL

They can be a b-i-t-c-h to fix....

Interesting about how the board powers the fuel pump.
I bought a trailer that has a Marquis Gold gasoline that the fuel pump won't run. I checked and no voltage at the pump. The wire goes to what looks to be a relay tucked in neatly behind the carb. I haven't probed the relay, but now I'm having my suspicions.
Another odd thing is that the remote switch doesn't control, even though it is plugged in. I know this thing probably wasn't run in at least a year. I'm afraid of what all I am going to find on it.

quote:

Originally posted by SCDIV1:
Welcome to my world Barry.....LOL

They can be a b-i-t-c-h to fix....

Onan serves up a curve ball, low and outside.. Swing and a miss!
Just when you think ah ha! Nope..

"It takes a tough man to make a tender chicken"

Persistence and doing the right diagnosis is the most important part...

Changing parts might work sometimes but it's not my M.O.

Yea sometimes you have to try things to eliminate them but I try to get to the root cause of the problem as much as possible before changing parts

He’s heading to LV for the Nats and points race. Has a Honda backup.. we’ll pull it later and check the mag, replace coils , belt and tensioner while In there. Just like mine….

I hate to say it but when you have an Onan, having a backup unit is a real good idea

I saw a Dog Groomer van last week typical of many I have worked on, repaired, service

The person driving it had a portable generator bungee corded in an add on carrier that goes in the hitch in the back

For the mostly woman who have those vans, it's about their only option other than plugging in at a customers home and that's not a good scenario for them. Not enough amps for their equipment.

The diesels are far more reliable but the gasoline machines, if used a lot of hours will potentially cause you problems

I have had 2 or 3 fairly newish machines that had an ignition coil fail when the machine got warm.

It's not a real common failure but can happen...

Like I said the big issues are tight exhaust valve lash, bad cylinder head/guides/valves after hard usage in an install that was poor and allowed exhaust heat to be drawn back in the machine

Very typical of a trailer or MH install. Exhaust heat side of generator underneath needs to be walled off and directed away from where the cooling air is drawn in the machine below the front and behind the oil filter area.....The heat is a killer and will prematurely cause head failures, carb failures, and just kill the machine...

This is for any new type (since 2001) 5.5 or 7kw Onan.....

I've spent the last 20 years fixing these things.......The old version is NOTHING like the new version and nothing is similar or relates.....

When one of my old friends was doing his total MC8 bus conversion. He decided to do the Kubota 12Kw for power.In the compartment i put in 2 large 18" fans in the compartment. Hot out, fresh air in.

We had it fed directly to the coach fuel system.

I’ve been looking for a diesel. Down the road …

quote:

Originally posted by TD3550:
When one of my old friends was doing his total MC8 bus conversion. He decided to do the Kubota 12Kw for power.In the compartment i put in 2 large 18" fans in the compartment. Hot out, fresh air in.

We had it fed directly to the coach fuel system.

Onan diesels ARE mostly Kubota engines and some are Isuzu

Problems are rarely engines.....both are very reliable...

PowerTech diesels are a mix of engines....Perkins/Cat, Kubota....I have worked on a number of PowerTechs.....Just got a call about one....

Generator companies build their machines with engines from various sources......Nobody makes their own engines anymore....

Onan did for years but that all went away

The modern Onan Gas burning air cooled engines I believe are built by Subaru/Robin but they have nothing on them that shows that is true.....

Onan shut down their engine plant in Wisconsin years ago......For a while they were made in Canada ad used the name Lindemar or something close to that.

If you go to Milwaukee and drive North on the main highway you passed some very big name manufacturers/builders and Onan was one of them....

I went to Appleton, Wisc. to Miller Electric years ago and drove up from Milwaukee......A nice ride....even in winter wasn't bad...if you like ICE fishing that's one place to go...past the big Lake...and thru OshKosh......

I remember the one year i got a call from the hospital here via a crane company. Goodall. The job was in detail to remove the radiator to be sent in for a re core Massive radiator. One of the engineers for the hospital had brought me down to the main power room. I could not believe what i was looking at with the 2 massive auxiliary power units. Twin turbo on the one. I would be lying if it wasn't an 8" exhaust.

The one year they he explained they had either a head problem or a bearing problem. Repair was north of $125K. Asked him how the ** do you get the block out of the basement. Remove a spec section of wall. There are emergency units that power the whole hospital. I was just like HS.

Okay so question for you Rich if you were going to build a toterhome of sorts and we’re going to buy a generator what brand would you buy

Me and my buddy once went to the "power house" that housed the electrical service and 2 huge generators.....

NJ's famous Rahway State prison and housing for mental patients.....The Name is different these days....

We were a good distance from the prison and this is not anyplace you want to be at for damn sure....High security and walls everywhere around the prison. We were not within those grounds.

The generators (2 or 3) were 4160 volts and huge.....air starters...We really had no business being there because we had zero knowledge of these things but our company owner would send us on any call pretty much anywhere....

There were a lot of dents in the ceiling and exhaust covering around 1 machine and I asked the guy we met there what that was about....

A turbo blew up and sent shrapnel pretty much everywhere....!!! He said it was bad, real bad. These things were old.....and so was the powerhouse and all the electrical panels....HUGE !!

We did run one of them and poked around in the fuel supply system looking for issues that would cause no starts or stalling....

They ran at some low rpm......I don't recall that number but it was under 1000rpm and they were really pretty quiet.....Huge mufflers....

I've been in buildings with huge generators.....some mounted outside and up 10-20 stories high. Some inside and just as high

Was at one I recall in downtown Newark, generator on an outside area right above one of the main streets of Newark maybe 5-6 stories up

Went to a building my mother worked in a good long while in Newark.....Generators being put in on top floor outside....Bambergers dept store...

Building was a 100 years old and laid dormant for years. Built so well they could set it up for cell phone equipment, generators, UPS....weight no problem....

Pretty good views in any of those buildings of NYC and the surrounding area if your up high enough...Been to NYC a few times as well including the WTC not long after 9/11


Generator world !!!

quote:

Originally posted by Top355x:
Okay so question for you Rich if you were going to build a toterhome of sorts and we’re going to buy a generator what brand would you buy

Onan's are really fine and go thousands of hours usually for their owners
The big problem is where they are mounted and the difficulty of fixing one if it has an issue
Toters usually have generators mounted in the rear left corner or a side compartment....
Side compartment may have some access but usually very limited
Rear corner probably the same deal
So anything other than minor service means pull unit out to fix....Not really that big a deal if installed in a way to make removal reasonable....
That is not gonna happen in the field with a 10 or 12 Onan or any other brand

PowerTechs are not bad either but they have their problems and I've seen racers wrestle with them.
Got a call about one just today....20 kw in box truck

I like them both but am partial to Onan's because I am a dealer, and a legacy shop and do warrantee as well sometimes...

I've worked on other brands here and there but they are in the minority and usually a cobbled together bunch of parts with zero support

I have seen Onan's with 10,000 hrs and still run fine.....5000+ regularly.

Hours doesn't necessarily kill them.....time and deterioration from road debris, moisture, rust....

Trucks with generators mounted BEHIND the rear wheels are subject to this problem

I have a Local Snap-ON dealer with a 8KW Onan diesel that has had numerous problems all from where it is mounted, behind the drive wheels and he drives in the road salt in winter

I've fixed it 3 times from wire failures from the corrosion.....and it's only 2-3 years old.....A total mess of green gundge, rust and wires rotting.....LOL

Our partial backup generator at work is powered by two detroits in tandem. Auto start. If you are in the room when they start, the hairs stand up on your arms. Damn they are loud!

Rich, in the big picture for racing setups, do you prefer the Onans, or portable Hondas?

quote:

Originally posted by Bucky:
Our partial backup generator at work is powered by two detroits in tandem. Auto start. If you are in the room when they start, the hairs stand up on your arms. Damn they are loud!

Rich, in the big picture for racing setups, do you prefer the Onans, or portable Hondas?

An Onan diesel would be number 1 but having a backup unit of some kind since your stranded at the track maybe for days is the way to go

Honda portables are extremely reliable

Onan's are too but they do have their issues and when it happens it can be tough to fix...

I have 2 Onan 4KW units and they both routinely shut down from being too HOT !

The one in my Class C motorhome has under 100 hrs on it and will randomly shutdown on hot days

The one in my trailer has run for days on end with no problems but will do the same thing on very hot days

Last year I had that issue one day at Maple Grove and borrowed my friends big pit fan and aimed it at the Onan.....It never shut down again that day

They are air cooled and heat causes vapor lock in the carb or fuel line is what I believe

I've seen this issue with other Onan models. The larger 5.5 and 7 kw twin cylinder units...

A Honda 3000 on a slide will run forever...

The big 6.5 and 7 Honda's same thing and they are out in the air.....

Only drawback is where to put them and having to unload and load them.

Onan's have numerous issues that can get you and do.

I get a lot of messages during race season from racers all over the country since everyone knows I will help them with advice....

While Ed was wrestling with his unit at Indy last year I had messages from others at Indy concerned about their machines.....and wondering if they should be doing something to prevent theirs from breaking down

To be honest the Onan's should be MORE reliable than they are but many people have negative experiences with them


JOB SECURITY for me.....LOL

After my experience last September at Indy with the Onan 10Kw onboard my motor home, that I fixed with Rich’s guidance, I spoke to all my neighbors around me with Onan generators onboard their MH and all have had issues and many of them were using a Honda generator and that was all I needed to see. I now have a Honda EU7000is on order.