I just Don’t Trust The Onan 4000, So...

DesertRatt · 03-05-2021, 06:51 PM

I’ve about had it with the built in Onan 4000. I’ve had it worked on. I’ve replaced the carburetor. Ran all the magic fluids through it. In the driveway it will start and run. Go out camping and it refuses to run at the worst moment. The way it’s jammed under the Winnie makes it almost unserviceable. It’s a coin flip whether it will run or not at any given moment.

Soooo, I’m thinking of a portable Honda. We only need enough juice for some flat TVs, small appliances, a few lights. I think 1000 watts would work.

I’m wondering is such a new Honda would be something a man could really rely upon? Or, are they fussy crap, o better than what I have?

dkoldman · 03-05-2021, 07:33 PM

Quote:

Originally Posted by DesertRatt

I’ve about had it with the built in Onan 4000. I’ve had it worked on. I’ve replaced the carburetor. Ran all the magic fluids through it. In the driveway it will start and run. Go out camping and it refuses to run at the worst moment. The way it’s jammed under the Winnie makes it almost unserviceable. It’s a coin flip whether it will run or not at any given moment.

Soooo, I’m thinking of a portable Honda. We only need enough juice for some flat TVs, small appliances, a few lights. I think 1000 watts would work.

I’m wondering is such a new Honda would be something a man could really rely upon? Or, are they fussy crap, o better than what I have?

How old is it?
How many hours?
How often do you exercise it?

Trick to try. Take picture of your driveway and put inside generator door and you may be just fine

powercat_ras · 03-05-2021, 09:12 PM

My Vista was made in December, 2014 so the Onan 4000 on mine is somewhere between 6 and 7 years old. It has about 220 hours on it. It seems to be starting easier as it gets more hours on it. I've changed the oil and air filter once.

I followed the break-in procedure when new and exercise it monthly.

Over time I figured out that using the stop button to prime the first time trying to start helped with starting. I hold down the stop about 5 or 6 seconds. I also figured out that I could hold down the start switch and if not started in 20 seconds, release and wait about 5 seconds, then repeat. Always starts by the 3rd time, usually by the 2nd time now.

= = = = =

The 1.6 kW Honda and/or Yamaha Japanese made inverter generators are good and usually start on the first pull, they are pull start. I had a 2.4 kW Yamaha when I owned a travel trailer many years ago, that was the smallest single generator that would run the AC on the TT.

Consider if you might ever want to use your microwave or AC off the generator when sizing one. A single 1.6 kW Honda for sure won't run the AC.

Don't buy a cheap 2 cycle 1 kW generator they are junk.

retiredpig · 03-05-2021, 10:24 PM

I agree with Randy. I had originally purchased a 1k gen big enough to just run my TV's and lights when we were trailer campers. It did not take long though and we were looking for something that would run the AC or the Micro. I have had the Honda 3k for several years now. I have countless hours on this gen and it is flawless. Although it has an electric start, I can always get it going with no more than a couple pulls with choke on. It is extremely quiet for a 3k.

I also agree...dont waste money on a 2 cycle 1K.

Phil G. · 03-05-2021, 11:37 PM

Quote:

Originally Posted by retiredpig

I agree with Randy. I had originally purchased a 1k gen big enough to just run my TV's and lights when we were trailer campers. It did not take long though and we were looking for something that would run the AC or the Micro. I have had the Honda 3k for several years now. I have countless hours on this gen and it is flawless. Although it has an electric start, I can always get it going with no more than a couple pulls with choke on. It is extremely quiet for a 3k.

I also agree...dont waste money on a 2 cycle 1K.

I'm curious ... your picture shows a good looking large Class A motorhome. What's wrong with firing up it's built-in generator to run the AC or Micro ... IAW why the need for the 3K Honda?

FWIW, I've stood close to a Class A with it's generator running ... probably a diesel generator spinning at 1800 RPM, and I had to listen real close to hear it at all ... very impressive indeed with very, very little noise! The folks inside the motorhome were probably hardly aware of it.

DesertRatt · 03-06-2021, 06:22 AM

Well, after some thought, I’m now looking at the Honda 2200i, which would run a microwave but not the AC and o think that will be fine. My only reservation is the pull start. Avenger I think of pull start I’m taken back 20 years to when I owned aStihl chainsaw that would have me so exhausted trying to start it that when it did finally start I was too tired to do the job!

I’m going to go look at the Honda and pull the cord to see how it feels. There’s also the weight and where to store it.

dkoldman · 03-06-2021, 06:59 AM

Quote:

Originally Posted by Phil G.

I'm curious ... your picture shows a good looking large Class A motorhome. What's wrong with firing up it's built-in generator to run the AC or Micro ... IAW why the need for the 3K Honda?

FWIW, I've stood close to a Class A with it's generator running ... probably a diesel generator spinning at 1800 RPM, and I had to listen real close to hear it at all ... very impressive indeed with very, very little noise! The folks inside the motorhome were probably hardly aware of it.

I with you here, short a major issue with onboard genset that simply does not work, I don't understand the logic of hauling a portable generator and gas cans? I have 10 year portable 3500 that purrs like a kitten. I wouldn't think of traveling with it, but at home I hook it up to the RV all the time to exercise it.

I have 2019 Onan 5500 with 88 hours. Never use the Prime feature, it always start on the 1st time. Only time I consciously know it is running is when AGS mode is Auto Quiet and overnight it is off but at 7:00 AM it turns it self on, it is under the bedroom floor so you can feel the vibration from when it first start.

I have changed oil & filter only once, but plan to change oil at least every year whether I hit 150 hours or not. New air filter every 150 hours for sure.

When my AGS was installed I had a chance to learn something that was contrary to my belief. The Engineer was emphatic that if you run the genset at least 1 or 2 hrs each month, your chance of issues drop off dramatically.

Before buying my RV , I use to Rent or try to rent and one thing that was turn off was owners charging so much per hour to run their genset. I knew it was to make a little more money, but I assumed a deterrent that more hours was bad for genset, and would probably hurt their resale value. I can't see me ever renting out my RV, but if I did, I was charge the rate I want and probably put a hrs/per day limit.

US1 · 03-06-2021, 04:06 PM

I tried a Honda 2000 to run my AC. It must be border line as sometimes the AC wont start, other times it would, but then the gen would error out within a couple minutes. I have since bought a 2200 Gen and it runs my AC no problem. My reasoning for the portable is it is way more economical and is quieter than the onboard gen which seems to resonate thru the RV, and its mostly to run the battery charger while boondocking.

**creativepart** · 03-06-2021, 05:36 PM

The Honda's are super easy 1-pull start machines when they are well taken care off. Even when abused they'll start with one pull AFTER 5 or 6 pulls if it's the first time in a month or more.

I could let mine sit for 3 months. Pull and pull for 6 or 8 times and it would start and run fine. Then anytime I needed to restart over the next days or weeks. It would start with one pull. It was only when the gas sat in the carb for weeks that it took multiple pulls to start.

I had two for 10 years. I never put anything but gas and oil changes into them Even had original plugs for all 10 years. They never let me down and I sold them on Craigslist in one day for 60% of the original purchase price. How can you not love that.

But sold them I did when I got an RV with a easy to live with reliable ONAN Genset.

You never disclose the age of your RV. Not even in your Profile. So, perhaps your RV is a 100 years old and your Onan isn't reliable because it was made in 1921. I don't know. But if it was me, I'd put a few hundred dollars into your Onan with a reliable Tech and get it running well.

DesertRatt · 03-06-2021, 05:53 PM

Quote:

Originally Posted by creativepart

You never disclose the age of your RV. Not even in your Profile. So, perhaps your RV is a 100 years old and your Onan isn't reliable because it was made in 1921. I don't know. But if it was me, I'd put a few hundred dollars into your Onan with a reliable Tech and get it running well.

My rig is a 2005 Minnie Winnie. I bought it about 9 months ago. It only had 13,000 miles on the chassis, and I think the Onan was barely ever used. Aside from the Onan, everything else in the unit worked very well.

I'm very unimpressed with the Onan design.If it was easily pulled from the vehicle to work on, it might be reasonable to service. But it's not made to be removed and the design is largely inaccessible causing massive labor bills for simple operations. 2 repair guys wanted $1,000 to replace the carb.. That's asinine.

I totally understand how some people love them and swear by them. But that's not been my experience.

powercat_ras · 03-06-2021, 08:03 PM

My experience helping others whose Onan 4000 gasoline generators don't start has been consistent, if they were neglected without being run for long periods as you say yours was as a rule it won't start. But there are on the RV cheap and dirty fix actions you can do yourself. Service centers don't do them because they take too much labor and time.

Generally, I'll try to get them started with air filter off with starting fluid and if they are able to catch and run, I'll let them run for an hour or three spraying some carb cleaner in the air inlet every so often to try to remove part of the built up varnish in the carb. This is also when you confirm that the generator has no other major problems like not putting out 120 VAC 60 Hz power and that it will carry load. If it has either of these issues then that's the end of cheap and dirty troubleshooting on the RV.

I'll also try doing that 3 hour run with fuel system cleaner in the RV gas tank with the generator under full load to maximize the amount of fuel with cleaner it draws to further try to clean the carb without removing it. Note this needs to be done when it's not too hot outside as the engine will want to overheat and trigger an automatic shutdown with the maintenance door off the gen in particular under full load.

If that makes it start-able again, then go ahead and spend the money to put on a new air cleaner and change the generator oil.

The other issue with this "cheap and dirty" maintenance is that you have to locate the RV somewhere you can run the Onan for 3 hours straight without annoying neighbors and breaking RV park rules if you are staying in a RV park.

If those "cheap and dirty" fixes don't work I refer to someone experienced working on Onan generators. As a rule Onan service centers will want to replace the carb in this situation. Onan does not support repairing the carbs apparently because of air emissions rules in USA and Canada.

Whatever you do once you get an Onan working, run it for a half hour every 30 days! Check the oil at least every 25 hours run time. Change the oil every 100 hours run time. Change the air filter every 100 hours run time.

Good luck.

retiredpig · 03-06-2021, 08:31 PM

As I mentioned, I used the generator when we were TRAILER CAMPERS. These days, you are correct, I just fire up that 8k Onan. But I still have that Honda 3K and it is still one of the best running pieces of equipment I own. Great gen.

Blastvalve · 03-07-2021, 06:54 AM

I can’t seem to find it (still working on coffee) but on IRV2 I remember reading about some 4000 models that would quit while running and not restarting until the unit had cooled down. The solution was to replace the fuel pump. May be worth a shot, they seem to run $14-$80 on Amazon.

Blastvalve · 03-07-2021, 07:53 AM

I’ve been searching both forums over my coffee and I can’t seem to find that thread. I’m positive I remember reading it, but without finding it I’m hesitant on my advice above. Obviously cheaper then buying a new generator, but I don’t want to advise you to just start tossing parts at it based on my memory!

**creativepart** · 03-07-2021, 07:57 AM

Quote:

Originally Posted by Blastvalve

I can’t seem to find it (still working on coffee) but on IRV2 I remember reading about some 4000 models that would quit while running and not restarting until the unit had cooled down. The solution was to replace the fuel pump. May be worth a shot, they seem to run $14-$80 on Amazon.

I had one of those issues on my SOB Class C. On very hot days when needed most it would run for an hour or two and then shut down. It would restart and run for a while then shut down again. It would keep doing this behavior but the run times would get shorter and shorter.

I always thought it was vapor lock.

I took the RV to Cummins and they ran it for two 8-hr days and it never stopped once. They used up half a tank of my gas. I guess it was not hot enough that day. They charged me $150 and did nothing but run it. They had a minimum charge. The guy that gave it back to me said they had heard quite a few complaints like mine but they were having trouble finding the cause.

We had a lot of other problems with that RV so we passed that football down the line when we traded it in. We disclosed all our issues but don’t know if things got fixed before it was sold.

powercat_ras · 03-07-2021, 08:10 AM

If you look at a Onan 4000 installation manual, Onan cautions that the generator has to be installed so that the hot air exhaust that blows out the bottom of the gen (it's air cooled) must not loop back and get sucked into the intake air slots on the side. If so on hot days the intake air will be too hot and the control board will do an over temp shutdown. I had this problem on mine. I found that I could leave the sidewall generator access door open on the side of the RV and prevent the over temp shutdown.

I created a more visually appealing (and quieter) solution so it would not overheat on hot days with the side door closed by using a rectangular to round HVAC air duct adapter mounted to the bottom of the Onan over the rectangular hot air exhaust port. This directs the hot air exhaust down farther below the RV so there is a much longer air path for the hot exhaust air to get sucked back into the air intake slots.

dkoldman · 03-07-2021, 09:10 AM

Quote:

Originally Posted by DesertRatt

My rig is a 2005 Minnie Winnie. I bought it about 9 months ago. It only had 13,000 miles on the chassis, and I think the Onan was barely ever used. Aside from the Onan, everything else in the unit worked very well.

I'm very unimpressed with the Onan design.If it was easily pulled from the vehicle to work on, it might be reasonable to service. But it's not made to be removed and the design is largely inaccessible causing massive labor bills for simple operations. 2 repair guys wanted $1,000 to replace the carb.. That's asinine.

I totally understand how some people love them and swear by them. But that's not been my experience.

You have just confirmed what a Onan Engineer told me. Onan sees your problem every day 100 times. You sound like a person that wants a portable generator? If so; buy it so you are happy. I have portable too (3500kw and it is enclosed power inverter and the noise from each is about the same, I actually think my 5500 is quieter if you are outside. I can only hear the genset from inside if I am in bedroom. With that said my view your view on the Onan 4000 is misguided. If you don't intend to use the Onan 4000 in future; it makes no sense for you to fix. You state it starts so you are half way there. Run Seafoam for 2 hours every day for a week and I your genset will purr like a kitten. Every time this thread keeps going, I go outside and let mine run for 30 minutes

Think about it, why would Onan would be willing to extend the warranty on EC-30 AGS if you have authorized dealer install on a Onan Generator? The Onan Engineer told me it was because the numbers don't like. Folks with AGS have significantly fewer problems than those that don't, and those with AGS have proven data metrics where there generators run more than those without AGS. He did not say, but I suspect there is some correlation with the type of person that wants to have a AGS to purchase as a add on versus the person that bought new coach that may had AGS installed by Mfg?

hank857 · 03-07-2021, 09:14 AM

If its a fuel no start I have used some stuff called 'mechanic in a bottle'. It is something that would require you to make a temp fuel supply but the stuff actually works. I have used it in my portable champion genset as it is one that is run very seldom. Also when putting the rv into storage mode I put 'stabil' into the gas tank of the rv and then run the genset while driving down the road for about an hour to make sure it gets into the gen system. Simple things but they work. Yes the onan is hard mounted to the chassis it seems thus the vibration but then you are not hauling another device along for gen power. The stuff I mentioned is something I would try before trying to replace, add a generator as the fuel now a days is not conducive to storage without treatent. There are several brands of gasoline treatments but I havent ever located any alternatives to stabil locally.

DesertRatt · 03-07-2021, 10:00 AM

If I make the decision to go with the portable, I will have someone cut the Onan out with a torch, and I will have them weld a shelf there to store the Honda.

I learned with lemon cars over the years that the "frustration cost" of unreliability and constant repairs can be higher than the dollar cost.

I've been asking around about "Onan experts." Haven't found one yet.

DavidM · 03-07-2021, 11:13 AM

For those who are fed up with the QG 4000 and want to replace it with something permanently mounted, consider the new QG 2800i an inverter generator. It is quieter since it runs slower when not heavily loaded and maybe more importantly has electronic fuel injection which should eliminate fuel varnish problems caused by water vapor contacting ethanol gasoline sitting for extended periods in the float bowl of the carburetor.

Not as much power as the 4000 but with judicious juggling you should be able to get by. The cost is about $3,000, a bit cheaper than the QG 4000. Sooner or later Cummins will come out with an inverter/EFI version of the QG 4000 and in time all gasoline RV generators will be made this way.

David