Good Sam Club Open Roads Forum: Class C Motorhomes: Replacement for Onan 4000
Open Roads Forum Already a member? Login here.   If not, Register Today!  |  Help

Newest  |  Active  |  Popular  |  RVing FAQ Forum Rules  |  Forum Posting Help and Support  |  Contact  

Search:   Advanced Search

Search only in Class C Motorhomes

Open Roads Forum  >  Class C Motorhomes  >  All

 > Replacement for Onan 4000

Reply to Topic  |  Subscribe  |  Print Topic  |  Post New Topic  | 
Page of 4  
Prev  |  Next
klutchdust

Orange, California

Senior Member

Joined: 06/09/2004

View Profile



Posted: 04/03/20 02:50pm Link  |  Quote  |  Print  |  Notify Moderator

I especially like this comment by grit Dog

"Just stop taking it places that charge $300 to replace a $30-60 carburetor. "

There are mobile mechanics out there that are ready and willing to work on just about anything.

I would suggest that one seeks out a mechanic in their area and check out their services and cost.

Now, I had my rototiller give me issues after storage even though I had fuel additive in the gas.

A product called mechanic in a bottle was suggested and is available at the big box orange store.

Well, as skeptical as I am i purchased, followed instructions and guess what, it idled smooth as

silk.

HTElectrical

Las Vegas

Senior Member

Joined: 02/09/2008

View Profile


Offline
Posted: 04/03/20 03:14pm Link  |  Quote  |  Print  |  Notify Moderator

Double Dose your fuel with Stabil, and you should never have a problem, as long as you run it every 2 to 3 months. I have been doing this for 11 years with my 4000.


2007 Duramax, Cognito 7"-9" Lift,


whemme

Spencer, IA

Senior Member

Joined: 08/26/2004

View Profile



Posted: 04/03/20 03:30pm Link  |  Quote  |  Print  |  Notify Moderator

True story. Several years ago I stopped at a RV generator shop in Flagstaff to repair my 4000 watt Onan that would quit running intermittent. Problem fixed with a new fuel pump. My Onan had around 450 hrs on at the time. I was telling the technician that we had a RV Club member that had 1450 hrs on his Onan. The tech said that a properly maintained Onan would last a lot longer than that. He said that north of Flagstaff is an Indian Reservation and all the homes are off the grid. He said that he maintains many Onan generators at these home sites that provide electric power on a 24/7 basis - generators running continuously except stopping for oil changes. These were 4000 watt Omans converted to propane fuel. He said he has one Onan that he services that currently had 38,000 hrs on it. Can anyone out there top that?


2002 Born Free 26' RSB Motorcoach
2005 Chevrolet Malibu LS Toad

klutchdust

Orange, California

Senior Member

Joined: 06/09/2004

View Profile



Posted: 04/03/20 05:58pm Link  |  Quote  |  Print  |  Notify Moderator

It would be interesting to know what exactly failed in some of the Onan generators and what it cost to repair. I find it curious that some have had multiple Onan's yet experienced failures in each one and others seem to have outstanding service using them. What occurred that would lead someone to not ever want to own one even if for free. As I have said, my company had no less than 500 units powering refrigeration units and other than normal maintenance were not in the shop unless they were getting a rebuild.

jjrbus

FT Myers FL

Senior Member

Joined: 07/19/2008

View Profile


Offline
Posted: 04/04/20 06:53am Link  |  Quote  |  Print  |  Notify Moderator

klutchdust wrote:

It would be interesting to know what exactly failed in some of the Onan generators and what it cost to repair. I find it curious that some have had multiple Onan's yet experienced failures in each one and others seem to have outstanding service using them. What occurred that would lead someone to not ever want to own one even if for free. As I have said, my company had no less than 500 units powering refrigeration units and other than normal maintenance were not in the shop unless they were getting a rebuild.


It is well known that any brand of generator in constant use will fare much better than an occasionally used genset.

For people that follow the forums the usual culprits are the carburetor and oil pressure sensor. If the circuit board goes out then it is $$$$$$$ for a replacement. I would offer a far superior replacement board if they have one for your genset.

https://pantherrvproducts.com/dinosaur-elect-300-3763-replacement-onan-generator-board/?gclid=EAIaIQobChMI5ob5zufO6AIVERgMCh3ktgi2EAQYAyABEgIRqfD_BwE

ron.dittmer

North-East Illinois

Senior Member

Joined: 02/26/2007

View Profile


Offline
Posted: 04/04/20 07:55am Link  |  Quote  |  Print  |  Notify Moderator

Hi CodyClassB,

I did not read through all the replies, so maybe this was covered.

Before spending a penny, before taking the rig in for generator service, first try these two things.

#1 - On your Onan, set the altitude adjustment to the proper altitude. It looks like this.
[image]

#2 - Many people don't know how to properly work the "prime" feature.

At your generator control panel, be very quiet. To prime the generator, you must push in the start switch in, but in the opposing direction (it is a rocker switch). HOLD it there and listen for any kind of sound. It would be the sound of the fuel pump running. If you hear nothing, have a family member press and hold it while you are outside under your Onan.

If you don't hear any hum or buzzing sound, then your fuel pump is not working. Check fuses and such. If your hear a hum or buzz, then your fuel pump works.

Then make sure your main fuel tank is at least 1/2 full.

People don't realize how long they need to hold in the prime button to get fuel from the main fuel tank to their Onan. Each rig is different pending the distance between them.

Prime, prime, prime. I advise to do as I do. Hold in the prime button for 15 seconds the first time and then try to start the Onan. If nothing happens, hold the prime button in for 10 seconds thereafter and repeat until it starts.

I never ever run my generator during the off season. I put the rig away in the fall and start everything up in the spring time. A few years, our rig will sit an extra year, and everything always starts right up. I do maintain the batteries during off season. This has been my practice with our rig for 13 years. We do store our rig indoors in a climate controlled environment which I am sure makes some difference. But I never understood all the talk about monthly start-ups and such, though some necessity if the rig is stored in the worst of conditions.


2007 Phoenix Cruiser model 2350, with 2006 Jeep Liberty in-tow


way2roll

Wilmington NC

Senior Member

Joined: 10/05/2018

View Profile


Offline
Posted: 04/04/20 08:32am Link  |  Quote  |  Print  |  Notify Moderator

I would say that the folks that do not exercise their genny with no issues are just lucky and the minority. We have a whole house generator, wired to it's own sub panel etc. It starts itself up weekly and runs 2 minutes without a load and then 15 minutes with a load and then removes the load and shuts down a minute later. Why do you think the engineers designed it to do that? Personally I want to know that my things are going to work when I need them to. And that means periodically running them and proper maintenance. Storing them for months on end without doing anything is rolling the dice. That's my opinion of course and YMMV. Maintenance aside, do I want to know in the spring while prepping for a trip that mice have chewed a fuel line or wire? Or do I want to know that when I have time to fix it? Put simply if you don't properly maintain things and ensure they work the risk of failure when you need it increases exponentially.


2020 F350 STX
2020 FR Cedar Ridge Silverback 29rw

Dusty R

Charlotte Michigan 48813

Senior Member

Joined: 04/05/2003

View Profile


Offline
Posted: 04/04/20 10:33am Link  |  Quote  |  Print  |  Notify Moderator

ron.dittmer wrote:

Hi CodyClassB,

I did not read through all the replies, so maybe this was covered.

Before spending a penny, before taking the rig in for generator service, first try these two things.

#1 - On your Onan, set the altitude adjustment to the proper altitude. It looks like this.
[image]

#2 - Many people don't know how to properly work the "prime" feature.

At your generator control panel, be very quiet. To prime the generator, you must push in the start switch in, but in the opposing direction (it is a rocker switch). HOLD it there and listen for any kind of sound. It would be the sound of the fuel pump running. If you hear nothing, have a family member press and hold it while you are outside under your Onan.

If you don't hear any hum or buzzing sound, then your fuel pump is not working. Check fuses and such. If your hear a hum or buzz, then your fuel pump works.




On the prime switch. I don't it will work from the start inside, you have to do that from the start switch on the generator itself.
Also, Listen very closely to the fuel pump when you are holding the switch. You can hear a difference when the carb bowl gets full, the pump it gets quieter.





Then make sure your main fuel tank is at least 1/2 full.

People don't realize how long they need to hold in the prime button to get fuel from the main fuel tank to their Onan. Each rig is different pending the distance between them.

Prime, prime, prime. I advise to do as I do. Hold in the prime button for 15 seconds the first time and then try to start the Onan. If nothing happens, hold the prime button in for 10 seconds thereafter and repeat until it starts.

I never ever run my generator during the off season. I put the rig away in the fall and start everything up in the spring time. A few years, our rig will sit an extra year, and everything always starts right up. I do maintain the batteries during off season. This has been my practice with our rig for 13 years. We do store our rig indoors in a climate controlled environment which I am sure makes some difference. But I never understood all the talk about monthly start-ups and such, though some necessity if the rig is stored in the worst of conditions.


ron.dittmer

North-East Illinois

Senior Member

Joined: 02/26/2007

View Profile


Offline
Posted: 04/05/20 10:11am Link  |  Quote  |  Print  |  Notify Moderator

Dusty R wrote:

On the prime switch. I don't it will work from the start inside, you have to do that from the start switch on the generator itself.
Interesting comment. I can prime from inside my motor home using the start switch backwards. If you are not setup for it, then most definitely pull the cover off the Onan and do it there. I would never be able to start my Onan after a long hibernation, if not for the process of extended priming.

Grit dog

Black Diamond, WA

Senior Member

Joined: 05/06/2013

View Profile


Offline
Posted: 04/05/20 10:26am Link  |  Quote  |  Print  |  Notify Moderator

way2roll wrote:

I would say that the folks that do not exercise their genny with no issues are just lucky and the minority. We have a whole house generator, wired to it's own sub panel etc. It starts itself up weekly and runs 2 minutes without a load and then 15 minutes with a load and then removes the load and shuts down a minute later. Why do you think the engineers designed it to do that? Personally I want to know that my things are going to work when I need them to. And that means periodically running them and proper maintenance. Storing them for months on end without doing anything is rolling the dice. That's my opinion of course and YMMV. Maintenance aside, do I want to know in the spring while prepping for a trip that mice have chewed a fuel line or wire? Or do I want to know that when I have time to fix it? Put simply if you don't properly maintain things and ensure they work the risk of failure when you need it increases exponentially.


No people who don't maintain their generators (or anything else) properly are lucky if they don't have issues.
While house system is designed to different parameters. It has large fuel reserves and is designed to operate automatically and presumably to preserve more critical systems than a portable or rv generator.
When my Honda 2k sits for more than a month or so, it needs a shot of fuel to start, everytime. Doesn't mean it's being destroyed by not being run.
Like I said earlier, frequent "exercise " is a bandaid for other measures. Proper layup eliminates or greatly reduces the "need" for other measures.

Theories presented by those who don't know much more than "gas n go" are not based off of fact, but rather the workarounds learned to prevent the bad situations.
Just like "Onans" are junk moniker. Carbs, oil sensors and fuel pumps top the list and are likely the greatest majority of issues.
But those things are only a big deal if you just "expect" something will work and not have an issue here or there.
Example, we own a wakeboard boat. Considered the top quality in that realm. The OE fuel pumps are junk for some reason, or were for about 15 years running.
People say that's junk and cost me $1500 on a $100k boat. But if you know what you're doing, it's a $100 part and a 1 hour fix with basic hand tools and you're good for another 500 hours.


"Yes Sir, Oct 10 1888, Those poor school children froze to death in their tracks. They did not even find them until Spring. Especially hard hit were the ones who had to trek uphill to school both ways, with no shoes." -Bert A.

Reply to Topic  |  Subscribe  |  Print Topic  |  Post New Topic  | 
Page of 4  
Prev  |  Next

Open Roads Forum  >  Class C Motorhomes  >  All

 > Replacement for Onan 4000
Search:   Advanced Search

Search only in Class C Motorhomes


New posts No new posts
Closed, new posts Closed, no new posts
Moved, new posts Moved, no new posts

Adjust text size:




© 2020 CWI, Inc. © 2020 Good Sam Enterprises, LLC. All Rights Reserved.