Community Forums

Jump · 02-21-2019, 03:17 PM

Quote:

Originally Posted by EdInArk

I almost wish the generator did not use the RV fuel system for gas for this reason. All my other carbureted equipment gets ethanol-free fuel, but it's just not practical to use it in the RV. I do run the generator an hour or so every month trying to keep it from jelling on us.

I installed an inline shut off valve on my Onan fuel line. That way I can run the carburetor dry after using it and prevent gumming problems.

Jump

rhomco · 02-21-2019, 03:33 PM

Don't even think about taking it to Camping World for repair. Find a CummingsOnan shop near you and take it there. Cheaper and far better service you can trust. Good luck on your project,
Rob

Piros1 · 02-21-2019, 03:37 PM

Quote:

Originally Posted by bikerv1369

My RV has an Onan Microlite 4000 generator that has been well maintained. It now starts but stops running as soon as I release the Start button. My mechanic identifies the problem as electrical and mostly likely due to wires being chewed by a rat or mouse. To fix the problem he says he'll need to drop the generator out of the RV to get access to all the wiring and check for other damage, and I suspect the work won't be fast or cheap.

In the interim, I can run my inverter with the RV engine idling and get the same power I get from the generator. At idle, my Ford E350 Triton V10 burns about 0.7gph, while running the generator burns about 0.5gph. At $3/gallon for gas, that extra 0.2 gallons costs me 60 cents per hour. BUT... for every 150 hours of generator usage I pay Camping World $150 for a generator service - which means NOT running the generator saves me $1 per hour in maintenance. In other words, looking only at these factors, it is 40 cents an hour cheaper for me to run the inverter with the engine idling than it is to run the generator. And for what it's worth, the RV engine runs quieter than the generator, and its exhaust is less of a nuisance. So my question is:

IS AN RV GENERATOR WORTH IT?

The replacement cost for my generator is over $3,000. And if the RV didn't have a working generator it would lose a lot of resale value, so that alone justifies going forward with repairs. But other than that, once it's repaired:

WHY RUN THE GENERATOR IF RUNNING THE INVERTER WITH THE ENGINE IDLING COSTS LESS PER HOUR?

One response I'd expect is that running the engine has a maintenance cost too, but at $75 per WalMart oil change every 3 months or 3,000 miles regardless, I'm not sure the incremental wear and tear would even be measurable.

WHAT AM I MISSING HERE?

To partly answer your question, if you are running you primary engine to keep your batteries charged then you should not be changing your oil based on mileage. I run a fleet of trucks and our CAT dealer stated that 1 hour of run time is equal to 43 miles driven so based on this and that you change your oil every 3000 miles you need to be changing your oil around every 70 hours + or -. If you wait 3 months and idle your engine 3 to 4 hours a day you could very easily be running 250 to 400 hours of run time on your coach engine or an equivalent of between 10,000 to 17,000 miles between oil changes. Way over what you are anticipating.

That is one point to consider and a second one is the cost of you coach engine to be replaced if you were to hire it done would be considerably more than your generator. And as others have said your resale value would be considerably less as well.

Winemaker2 · 02-21-2019, 03:46 PM

Idling main engine not the best treatment for an expensive and important component. Also batty charging via alternator not the best.
Treat a gen properly and they will last a long time and serve you well.

DynoDon · 02-21-2019, 03:46 PM

Quote:

Originally Posted by EdInArk

I almost wish the generator did not use the RV fuel system for gas for this reason. All my other carbureted equipment gets ethanol-free fuel, but it's just not practical to use it in the RV. I do run the generator an hour or so every month trying to keep it from jelling on us.

My Diesel Pusher had an LP Generator which I didn't care for and when it started to act up I decided to replace it. I was originally going to go Diesel, but the cost, and fact that I only have a 65 gallon tank made me decide to go gasoline. I picked up a used 5500 watt genset for $1000 (at least $4,000 cheaper than any decent diesel) and put a 25 gallon gas tank in one of my basements. That fuel is only for the gen and I don't have to worry about it using crappy ethanol. Just a thought - you could put a separate tank in yours for the Gen.

DynoDon · 02-21-2019, 03:50 PM

Quote:

Originally Posted by Jump

I installed an inline shut off valve on my Onan fuel line. That way I can run the carburetor dry after using it and prevent gumming problems.

Jump

Only thing is, they don't run dry. There is always a little fuel left in the bottom of the float bowl, and that will gum up and continue to build until it blocks the pickup tube in the bowl. Ask me how I know ...

A32Deuce · 02-21-2019, 03:53 PM

Yes, but if you run SeaFoam in your main tank, then the gen bowl will get cleaned out!

Roadyacht · 02-21-2019, 04:08 PM

I purchased a 2-year-old RV with an Onan Microquiet 4000 gas generator which had 11 hours on it. I changed the oil soon after purchase because I didn't see where it had been done. I experienced a similar situation shortly after purchase. I checked the wiring. Our unit doesn't have a low oil cut off. I replaced the spark plug and air filter. I went through the process of checking the fuel pump operation. The fuel pump was non-operational. I purchased a new fuel pump and installed it myself. It is an in-line fuel pump. I haven't had a problem since.

Kid Shilleen · 02-21-2019, 04:22 PM

If it starts and runs with the start button depressed, check for a faulty relay in the start circuit.

Kountry_star · 02-21-2019, 04:42 PM

Had an Onan 4000 on our first MH 1990 Flair. Had the same problem, started but shut off as soon as starter was released. We where traveling in Southern Utah / summer / with marginal dash air. needed the generator. Took it to a onan service center in St. George. They went through a complete check out. Removed and checked each removable board. Tracked problem down to a specific circuit board. They didn't have it closes place that had one was Las Vegas. They put every thing back together. Then just for the heck of it tried to start it. Started as it should ( Never had another problem for the next 3 years we had that MH). They figured it must of been a corroded connector. Charged us $ 100 for tests we where happy.

As for your mechanic saying chewed wires. Either doesn't know how to troubleshoot or is lazy. We did have extensive rodent damage on a generator in a 1998 Pace Arrow. Being rodent damage (act of God) insurance paid for everything ($2650) less our $100 deductable.

Get an estimate from an independent on your oil change. Bet it won't cost $50. Would hate to hear what CW charges to change the oil for the coach's engine. As an example, we got a quote from CW for new Koni shocks for our present coach they gave us an quote of $2109 installed. Shopped around a bit. Got the exact same Koni shocks (from Summit), had them installed with the coach sitting in OUR garage by a mobile service. Total cost $960. Got to shop around if your not made of money or shopping for a 2020 Prevost Foretravel.

Igeaux · 02-21-2019, 04:55 PM

:roll eyes:

Onan Gensets are the easiest piece of machinery to work on I have ever encountered.

The Onan service manuals are excellent. The diagnostic procedures take you step by step through the troubleshooting until you walk head first into the problem.

We have been servicing our Onans since around 1973 on both Boats and RVs. 99% of the problems were with external components. As mentioned several times in this thread, gummed up carbs, low oil, malfunctioning sensors, plugged up filters and corroded connections are the usual suspects.

Our old GMC motorhome has an Onan MH6500 Generator that has over 8000 hours on the clock. It has failed to run 2 times that I know of. 1 bad oil pressure sensor and 1 dirty carb. I talk to the people who bought it from us several times a year. They have not mentioned a single problem with the Onan.

I can not wrap my mind around a $150 generator service. Fifty bucks for a full service with all filters and Mobile1 would leave lots of profit for the mechanic. Maybe I should start a Speedy Onan-Oil-Change business.

Buy yourself a set of service manuals, a tool box and some of those cool Mechanix gloves and jump in the deep end....

Now, if you had a Generac, dump it off the Bonnet Carre your next trip across the I10.

I usually listen to Guy Clark when I change Oil... Things that work, things that hold up, things you don't hang on the wall.

Jchemie · 02-21-2019, 04:56 PM

You’ll put way too much wear on the coach’s motor. Remember, the coaches engine will have an EGR valve on it. This valve will gum up fast while idling, whereas a generator is designed to idle for hours on end and doesn't have an EGR valve. At least none do from what I’ve come across. You may want to check another RV repair shop or private shop for a cheaper estimate.

Pozo · 02-21-2019, 05:01 PM

Our 5th wheel has a LP 5500 Onan on board. When it was only a year old we were in Alaska in a park without a good power source. We really needed / wanted our generator but it wouldn't start. Upon returning home I started tracing the various bundles of control wires. I found one wire that was loosely hanging down that apparently had worn through the insulation shorting it. I'm not sure what that wired did, but removing the worn part, soldiering the wire back together and covering with shrink tubing fixed the problem.

PeterFTH · 02-21-2019, 05:02 PM

First, check with the engine manufacturer about the hazards of excessive idling - there are several. Second - if the generator starts but stops when you release the button, it could be a simple relay not working - are there other signs of mice or rats? While not impossible, it seems unlikely. As for generator service, it's a total rip off. I change my own oil and filter (Cummins/Onan 7.5 KW) for about $25 in oil and filter costs. It's simple - drain, replace, refill. How they charge so much and people pay it is beyond me. Try another service place - an automotive electric shop (starters, alternators) and see if they can troubleshoot it for you. Get a schematic first - but I'm betting it's a relay hanging up. Peter.