repairing Rialta Onan generator

[Charlie]

I have a 2004 Rialta with a 2800 w Onan gasoline generator that hadn't run for 2-3 years or more. When serviced the generator would start, then belch out black smoke and die after about 30 seconds.


The mechanic believes that gas is getting to the carburetor but something is preventing the generator from continuing to operate after starting.


Any ideas? Is there a carburetor cleaner that can be used? If so, what brand? How do you do it?


The cost of repairing this problem is causing anxiety. I hear that the generator has to be removed from its housing for further repairs and the cost of that is astronomical. Any insights?

[CGAZ Paul]

Hi Charlie,


It shouldn't be "astronomical" as far as removing the generator. At first it seems scary but if you can rent or borrow a small hydraulic table or lift, or otherwise something to lower it upon, the removal isn't that hard. There is quite a bit to disconnect; including the muffler, fuel line, wiring, etc.. If you have a service place do this the cost will be there but if you do it yourself (as I did) it is just a short term grueling chore. There could be many things wrong that would cause your problem. Best to go to an Onan "certified" repair facility. Replacements can pretty much run around $1,000 per KW (or $3,000 in this case). This is why people need to run these properly and read the manual on startup and shutdown procedures.

[Jim Sturges]

The generator problem is probably the built-in voltage regulator or the printed circuit board module.
Both are easily accessable from the botton (underneath) of the generator. The first thing I would go after is the printed circuit board module. It comes out easily. It is the assembly with the start/stop switch. When I had trouble, I sent it to a company near Harrisburg, Pa. The company is called Flight Systems. You send them the assembly and they will check to see if that is your problem. If it is the problem, they will credit the test fee toward the purchase of a replacement.


If it checks out OK, the next step is the voltage regulator. It too, disconnects easily. A good electrronics guy can run some tests on the regulator to determine if it is functioning properly. If it is not you can order a replacement from Flight Systems. The install is simple.


The generators in the Rialtas were not Onan's finest hour. The more you know about them, the happier you will be.


I hope this has been helpful. If you desire, E-mail me at jimterry56@aol.com and we can chat more.