Gasoline Engines: The noisy end of an RV genset needs to have its’ oil changed once a year even if it hasn’t accrued enough hours for the change. With atmospheric changes, moisture gets into the engine and forms a very weak sulphuric acid in the oil. If left over a period of time the acid will gradually etch the bearing surfaces and the piston rings. Synthetic oil lessons this to some extent but the problem is still there. Filters should be changed at the same time. Oil filters are cheap, the engine block is not. Horizontally mounted oil filters should have anti-drain back valves in them so some oil will be left in the filter for the next starting cycle. Air filters should be checked for oil contamination that plugs up the filter paper and causes excessive fuel consumption and rough running. If possible, replacement fuel filters should be clear plastic and installed so that any water or dirt caught in the filter is to the outside so you can see it. Spark plugs and point sets are usually sold in kits and keeping a kit in the storage compartment is a good idea along with the tools and instructions to replace the points.
Diesel Engines: These engines are more critical to air pockets and cleanliness in their fuel systems than gas engines. Special care must be taken when reinstalling and priming the fuel system. Diesels generate more pressure on their bearing surfaces due to the diesel cycle than gas engines and heavy duty oil must be used in them. Mufflers on diesel units should have their cleanout plugs removed periodically and the carbon blown out.
Generators: The electrifying end of the genset should be checked for dirt in the cooling ducts. On some units, rodents can get into the space between the engine and the generator. They usually break the ignition rotor when they do and it is expensive to change out. Generator brushes and slipring resistance should be checked once a year and the rings cleaned if necessary.
Control: The control board should be checked once a year for bad connections or cracks in the sealing compound that protects the board from moisture. Unplugging and replugging the control plug usually takes care of any slow buildup of corrosion.
Sheet metal and mufflers: The exterior sheet metal covers of the genset should be cleaned and inspected for cracks and looseness once a year. The high vibration of the units causes sharp corners and bolt holes to have a tendency to crack if not checked periodically. Mufflers should be checked for excessive carbon buildup, rusting out and mounting integrity.
Generator Jim
Bruce Manley
Great article ! I have one question, which is this. Our gen set, a gas Onan 4 kw, less than 1 yr old in a class C is hard to start. How long do u suggest I hold the prime switch on(indicated by a red light) prior to using the starter ? The unit has “not” been run dry just sitting for some time during the winter.
Anne
Jim, Your information has been great, but I can’t find anything on our specific problem. We just bought a ’93 Fleetwood Flair. Everything is working great, except our generator switches.
I first noticed that I could not turn on the generator with the cabin switch OR the on switch on the generator. Dead, nothing happened. I started the engine and was able to start the generator with the in cabin switch. Ran the generator a while and turned off with the in cabin swithc.
Next time I started the engine, the generator started and I could not turn it off with either switch. I had to remove the spark plug wire to get the generator to turn off.
Any ideas?? I’m pretty handy and comfortable with basic electrical work. I’m no electrician but have done a fair amount of wiring.
Thanks for any wisdom you can share!!
Anne & Shorty
FRANK
THANKS
THIS COVERED ALL I NEEDED TO KNOW. THANK YOU VERY MUCH.
FRANK