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Replacement for Onan 4000

CodyClassB
Explorer II
Explorer II
My Onan 4000 which only has about 80 hours stops working. I think it is because I do not exercise it monthly. I pay around $300 to replace the caburator, but I am thinking about buying a portable generator (link below) . Questions:

1. Will 2000W generator able to run AC in a 22 ft RV (Model is winnie minnie 22r)
2. Do you still have to exercise portable generators monthly?

thanks

https://www.walmart.com/ip/A-iPower-SUA2000i-2000W-Digitial-Inverter-Generator/784816626?irgwc=1
35 REPLIES 35

HTElectrical
Explorer
Explorer
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,

klutchdust
Explorer II
Explorer II
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.

jack_the_Machin
Explorer
Explorer
You can buy a replacement carburetor on eBay for less than $40.

https://www.ebay.com/sch/i.html?_from=R40&_trksid=p2512315.m570.l1311.R4.TR11.TRC2.A0.H1.Xonan+4000.TRS0&_nkw=onan+4000+carburetor&_sacat=0

Grit_dog
Navigator
Navigator
It’s understandable not everyone has the spare time to exercise their stored vehicles, tools, equipment and toys.
If I did it monthly to every engine that gets used seasonally, I’d have an average of at least a dozen items to fire up, year round, every month.
Proper maintenance and the most applicable combination of fuel care from drain/run dry to stabilize the fuel to use fuel that can handle long term storage is the key.
I’ve used Onan built in generators , never owned one or more to develop a personal opinion on their reliability, so cannot comment specifically to those that take proper care and still have issues, but I would bet that a lot of the issues are due to lack of maint/storage technique vs being inherently unreliable.
2016 Ram 2500, MotorOps.ca EFIlive tuned, 5” turbo back, 6" lift on 37s
2017 Heartland Torque T29 - Sold.
Couple of Arctic Fox TCs - Sold

PSW
Explorer
Explorer
I have had motorhomes off and (mostly) on for almost forty years now and have had an Onan problem one time. I forgot that they shut off if the gas level in the rv tank is about 1/4 or less full. About means about I found out.

Fortunately, I live in an area where I can store my C within a few miles of my home and our winters are a few days cold, a few days nice for the entire season. So, on a nice day around the first of the month every month I get it out of storage and drive up the highway about 30 miles with the generator running and under load. I stop, eat a burger for lunch in the little town up the road, drive back to the storage and another month's maintenance on the rv and generator is done. One sixty mile trip and a couple of hours time including a burger and fries is a small price to pay to keep my rig ready for travel season.

Of course, I change the generator oil, change or clean the filter and do all the other normal maintenance as required as well but I have concluded that exercising it is a cheap price to pay.
PSW
2013 Phoenix Cruiser 2350
2014 Jeep Cherokee behind it
and a 2007 Roadtrek 210P for touring

miniwinipowerst
Explorer
Explorer
There is give and take in life. Pulling a cord is a small inconvenience. Knowing that you have a 99.999% chance that you will have power while boondocking is important to me. Nothing stinks more than when you need power and it doesn't work. I constantly had issues with my LP 3600/4000 Onan with updated maintenance (probably over maintained) and religiously exercised. How many times does it take to give up on a piece of equipment that constantly lets you down? Usually I'm not one to give up on equipment but this Onan was not the first one to give me problems. Friends and family that are mechanics also complained about the problems with their Onan generators. The Honda's that I purchased (2000's) I converted to LP and work very well, sip LP, are super quiet, portable if needed, low vibration, last forever, low maintenance (don't need exercised), only have to run one gen set most of the time unless you need AC, etc. I am very happy with my decision.

way2roll
Navigator
Navigator
A maintenance free generator (or any RV, or anything RV related) doesn't exist. While it is true you can keep buying generators to avoid doing maintenance on them, it's not very cost effective. Like I said before, not trying to be snarky, but if you don't have the time to take care of it, don't use your Rv except a few times a year, you could probably save a ton of money and aggravation not owning one and renting instead. As you are finding out, not maintaining your RV leads to problems. Those problems lead to more time and money you already said you don't have and an RV that is depreciated greater than it should be if you ever decide to sell. Good luck.

Back on track, I would find a cheaper place to work on your genset, fix it, and learn how to maintain it. I know you said you don't have the time, but look at the time and money you are going to spend now. It's much greater than the time it takes to do preventive maintenance.

Jeff - 2023 FR Sunseeker 2400B MBS

Dusty_R
Explorer
Explorer
On one of our mh Onan generators I put a switch on the electric fuel pump. Then when I knew that we were not going to use it for a while, I start it and let it run a little while, then turn the fuel pump off, and let the generator run out of gas.

Grit_dog
Navigator
Navigator
cody, be more specific what the problem is. Presume your overpriced carburetor job means you're having fuel delivery issues, or is it something else?
Agree, makes no sense to junk a basically new built in 4k generator unless you ran it out of oil or something catastrophic. Just stop taking it places that charge $300 to replace a $30-60 carburetor.
On to the myths. Generators DONT "need" to be excercised monthly or anywhere near that. No more than your lawnmower or car. Who starts their mower every month all winter, lol!
However regular starting is an ok band aid for lack of proper layup or maintenance. Regular use with degraded crappy gas will have a better chance at keeping it from getting varnished or gummed up than letting it sit. That however is the only reason for frequent operation.
However simply running it out of gas also eliminates the possibility of the above issue.
Starting ease and running quality is greatly increased with quality fuel as well. Likely the OPs issue, feeding off a tank or **** gas in the rv that has sat for months with no consideration for that.

Excercising to maintain residual magnetism between the armatur and windings is not needed monthly either. LONG term storage or another issue can kill the magnetism and require re-exciting the generator, which is also easy. But in 30+ years, I've seen one dead generator and idfk how long it sat, but years though.

Bottom line, just take care of the generator the right way if you don't want to band aid it and you won't have issues.

And for portables or any other small engines, non ethanol with stabilizer/sea foam if you can't or aren't going to run out or drain the carb, or AV gas or race gas will do wonders to keep from varnishing the carbs. Want to start a small engine reliably even a year or 2 later? Spend a couple bucks and store it with AV gas in it. Plus it smells better!

Another myth. Unless you have a metal fuel tank or super wet climate/ stored out in the open, condensation in an empty fuel tank is a non issue. Way better to fill up with a tank of fresh gas than have to use a tank of crappy gas. If water is a concern, that's the one great thing about ethanol gas. A little water will be absorbed by a fresh tank of e10.

Why do you think frozen fuel lines are a thing of the past? Ethanol blend gas is to thank for it.
2016 Ram 2500, MotorOps.ca EFIlive tuned, 5” turbo back, 6" lift on 37s
2017 Heartland Torque T29 - Sold.
Couple of Arctic Fox TCs - Sold

klutchdust
Explorer II
Explorer II
CodyClassB wrote:
way2roll,

I appreciate your replies. I am a full-time worker with 3 young kids. We live in Southern CA . We only do RVing in spring breaks or summer time. I find it is too much to exercise the Onan monthly and only use it 2 or 3 times a year. Now that the Onan is broken, I am deciding to get it fixed or buy a generator where we do not need to exercise monthly .

way2roll wrote:

On edit:
I reviewed a few of your other posts an it seems like you have an RV that only gets used 1 or 2 times a year. As a result you are having issues due to lack of use. RV's - like anything else - like to be used or they start to have problems. Have you considered that you may actually be spending more money addressing things from lack of use than selling it and renting an RV for the 1 or 2 times a year? Again, not trying to be snarky, just a thought.


All generators need to be exercised regardless if they are under the rv or portable. It has to do with the windings. The engine is one issue.

CodyClassB
Explorer II
Explorer II
way2roll,

I appreciate your replies. I am a full-time worker with 3 young kids. We live in Southern CA . We only do RVing in spring breaks or summer time. I find it is too much to exercise the Onan monthly and only use it 2 or 3 times a year. Now that the Onan is broken, I am deciding to get it fixed or buy a generator where we do not need to exercise monthly .

way2roll wrote:

On edit:
I reviewed a few of your other posts an it seems like you have an RV that only gets used 1 or 2 times a year. As a result you are having issues due to lack of use. RV's - like anything else - like to be used or they start to have problems. Have you considered that you may actually be spending more money addressing things from lack of use than selling it and renting an RV for the 1 or 2 times a year? Again, not trying to be snarky, just a thought.

pnichols
Explorer II
Explorer II
VA-Apraisr wrote:
Had my Onan rebuilt after 1400 hours on it since I boondock a lot. Cost about $1800 for everything and now have 1700 hours. I turn it on to run microwave while cooking and couldn't imagine having to go outside in weather to pull start the generator(s) each time. As with all mechanical things, you gotta use'em or lose'em.....sitting idle just doesn't work well.

Wonder why Honda stopped making generators??.....if it was an upgrade to an Onan, why is it no longer available? I love my honda truck and grass mowers and just a sincere question.....why don't they do RV generators?


X2 here on what you say about your Onan!

We've had an Onan 4000 in our Class C for around 14 years now, and it's never let us down. I try to run it 1/2 to 1 hour every month with a load on it.

I also carry a little super quiet 650 watt Honda portable along with us for just-in-case backup. The little EX650 Honda is at least 30 years old and still starts up on the 1st or 2nd or 3rd pull. I've only had to replace a small section of it's rubber gas line. Some years ago I installed an E3 spark plug in it for added reliability, plus I use synthetic Mobil 1 oil in it. I also use an E3 spark plug and Mobil 1 oil in the Onan:

https://e3sparkplugs.com/
2005 E450 Itasca 24V Class C

VA-Apraisr
Explorer II
Explorer II
Had my Onan rebuilt after 1400 hours on it since I boondock a lot. Cost about $1800 for everything and now have 1700 hours. I turn it on to run microwave while cooking and couldn't imagine having to go outside in weather to pull start the generator(s) each time. As with all mechanical things, you gotta use'em or lose'em.....sitting idle just doesn't work well.

Wonder why Honda stopped making generators??.....if it was an upgrade to an Onan, why is it no longer available? I love my honda truck and grass mowers and just a sincere question.....why don't they do RV generators?

jjrbus
Explorer
Explorer
Let me start with I am biased and would not take an Onan for free. Paying for parts is one thing, I refuse to own something where I get ripped off for parts. I had a nice Honda EV4000 and let it go with an RV I sold and have kicked myself ever since.

So I have my nice little Toyota set up with a 8000 btu window AC and run it with a Honda 2000. The Honda is in a sound box, basically an modified aluminum truck tool box. Could it be stolen, of course they could also take the whole RV!

There is one option for running An AC with small generators, I have not tried it yet so will not recommend. If needed I would spend my money on one!

https://www.microair.net/collections/easystart-soft-starters/products/easystart-364-3-ton-single-phase-soft-starter-for-air-conditioners?gclid=EAIaIQobChMI14Ko2q3K6AIVB2KGCh2kYwBoEAQYAiABEgJzTPD_BwE&variant=30176048267

They tell me Honda replacement parts are expensive, I do not know as in 20 years I have never bought a replacement part. Except for a pull cord and that was generic!

klutchdust
Explorer II
Explorer II
In my industry we had maybe 500 Onan generators and they proved to be a workhorse and very reliable. They need to be run and run a lot.
Replacing with portables seems to be a costly solution to a small problem. Storing them, carrying fuel....no thanks.....

Servicing your unit then using it like it was designed to do may be the best option for both ease of use and dollars spent.

Portable units. Always turn the fuel supply off and let the unit run out of fuel. This will prevent fuel from gumming up in the carburetor.

I have a 10 year old Champion that has seen plenty of abuse. It sits sometimes for months and once i turn on the fuel, wait a minute, half choke and half

a pull it starts right up. i started using non-ethanol gas in my saw and rototiller. I still include fuel treatment though.