Forum Discussion

tdelliott's avatar
tdelliott
Explorer
Sep 17, 2021

Gen-set Troubles

The DW and I have decided that we either need to repair our Onan onboard 4KW generator or add a generator to our 2014 Class C. the current onboard gen starts very well, runs for about 7-10 minutes, and then quits. After a short (1 HR?) wait, the same sequence of events. It seems like there are three options available to us, and I don't know which way to go. I appreciate all your advice.
1) repair the onboard gen ($$$$) or purchase and install a used onboard gen in the gen-set compartment (again $$$$). Getting a dedicated RV gen installed would probably be the "cleanest" build and, unfortunately, the most expensive. Not sure I want to invest that much. This option also doesn't include if all the connections are still good.

2) Install a portable gen set on a rear platform on a semi-permanent basis. I would have to purchase a secure box for it, the fuel, cords, etc., and have it mounted to the rear cargo rack. Possibly cheaper and would add storage to boot. The downside is that I lose the hitch's use (not using it currently, but you never know), and it may make a tempting target. It also increases the Length Of Rig by about 1.5-2.0 ft. Since I don't use a toad, this may make a difference on a 31' MH. On the upside, I could transfer the set-up if/when I purchase another unit and use the portable gen-set for other projects around the house.

3) I could carry and set up a portable gen-set when I park. If I get a new or used gen-set, I need one big enough to run the A/C, the coffeemaker, and the microwave, sometimes simultaneously. That limits me to a pretty good-sized gen-set. The only way I could make it work would be to carry a pair of 2000s inside and connect them in parallel when I park or get a 4500W unit that is heavy and difficult to store. I don't think two gens would fit in my exterior compartment, plus I would want that space for optional storage. I think a unit big enough to run the A/C would take up too much space inside when traveling. I guess I could still put them on a receiver rack, but that brings me back to option 2, so I'm confused.
I initially thought that having a gen-set was a great option but not required unless boondocking or during emergencies. I appreciate all thoughts on generator set-ups, economics, and necessity.

4) other ideas?
  • do you run the genny under load once a month for at least 30 mins regardless of time of year? if no, the carb may be fouled up and a new one is needed. they gum up very easily. stabil gas treatment make no difference.
  • I had this exact same thing happen and all it was , was the ground wire was corroded. Simply scraping it clean and reattached it and generator ran like normal. Just a thought…….
  • My best guess is that you have a failing electric fuel pump. Replacing it along with a new fuel filter will cost a lot less than a replacement generator.
  • If all the above is not helpful then the fuel pump and filter would be my next suspects. The fuel pump can be tricky to get at.
  • Check oil level , onan 4000 is 1.6 qts. The dipsticks are off their mark. It should only be 1/2 way to full. Too much oil can cause your condition.
  • Another idea.....

    This would seem to be an engine problem. So, call around to any small engine shops you can find and ask if they will work on it for you. I don't know how easy yours is to get to, if it is tough, they might want to take it out, but I guaranty that they can make it work and for less cash out of pocket than a Cummins shop.

    We see a lot of this in our group, but ours are all near 50yo and we have rubber fuel lines cracking.

    Matt
  • Take it to an Onan dealer and get it fixed. Not a service shop. A Cummings Onan dealer they know what to do. All that other stuff will cost you the same or more $$ if you use it like I do I would be lost without it..jmo.
  • We have an Onan 4000 gen. in our C-Chevy 450 chassis w/6.0 gas engine. Our chassis gas tank has to be 1/4 plus full for it to run. We had to replace the carb and fuel filter, air filter-thru Amazon-and runs great now.