Learning how to properly maintain a built-in or portable generator can save time, trouble and money
As a trailer owner, it probably took you only a few camping trips in the boonies to realize that your home on wheels wasn’t really designed for long-term camping without electrical hookups. Hey, you’ve got a battery (or two), right? How much power could a few lights and a refrigerator take, anyway? As it turns out, quite a bit. And if your trailer is outfitted with all the comforts of home, like a microwave, television and air conditioning, they’ll be little more than electronic paperweights without a steady supply of 120-volt AC power from a humble generator.
Whether you power up with a small portable unit or own a toy hauler or fifth-wheel with a built-in model, you rely on a generator every time you camp off the beaten path. Yet, paradoxically, most of us don’t maintain our generators properly. You wouldn’t think about buying a tow vehicle, driving it a few miles each summer and then ignoring it for the rest of the year, but that’s precisely what a lot of RVers do. A generator is comprised mainly of an engine — one that shares a lot of similarities with other engines including a carburetor (or a venturi in LP-gas generators), air and oil filters, belts and other components. You may have grown accustomed to that power plant roaring to life whenever you pull the cord or push the Start button, but all it takes is a few months of neglect, and your generator could go on strike when you need it most.
To get some expert advice on generator maintenance, we visited Smith Powerhouse, Inc. in Bellflower, California, a factory-authorized service and warranty center for Cummins Onan, Honda, Kohler and Generac generators. Owner David Voloshin and shop foreman Matt Rudametkin are certified master generator technicians who have nearly 50 years of experience between them, and they’ve seen it all.
By far the most common built-in RV generators in use today are the 4,000-watt Cummins Onan (known as the MicroLite 4000, MicroQuiet 4000 and RV QG 4000), its 3,600-watt LP-gas variant (MicroLite, MicroQuiet and RV QG 3600 LP) and the larger Cummins Onan Marquis Gold 5500 and 7000 (also known as the RV QG 5500 and RV QG 7000), and their propane counterparts, the Marquis Gold/RV QG 5500 LP and 6500 LP, so these will be the focus of this article. There are a lot of good choices for portable generators as well, but from our experience, the most popular model among RVers is the 2,000-watt Honda EU2000i, so we’ll be covering maintenance tips on this model as well.
Now, while the most frequent types of maintenance, such as oil/filter and spark-plug changes, shouldn’t prove too challenging for most DIYers (and can save some time and money), Smith Powerhouse recommends against more advanced maintenance procedures for two important reasons. One, you will likely do more harm than good if you don’t know exactly what you are doing, and two, you can seriously hurt yourself. When it comes to major scheduled maintenance, it’s best to leave the heavy lifting to experts like Smith Powerhouse.
With all that said, let’s take a closer look at what makes our favorite generators tick.
| 1) Other popular Cummins Onan generators are the gas-powered 5,500- and 7,000-watt models (typically found in larger toy haulers) and the 5500 LP/6500 LP found in some fifth-wheels. This is a V-twin engine oriented on its side, with the valve covers facing up (the right cylinder is visible). Though it is a completely different design from the 4,000-watt generators, many maintenance procedures are similar. Note that the oil fill/dipstick is in the same location as the 4000/3600 LP.|
2) The air cleaner uses a paper element that is readily accessible from the front of the unit. Simply unsnap the clips, and the cover comes right off. This filter element still looks good.
|3) Draining the oil on the 5500 and 7000 is simple, since it uses a petcock instead of a drain plug. Warm the engine for about 10 minutes, then put a pan underneath and open the petcock; the oil is routed underneath the RV through a rubber hose.|
|4) Unlike its smaller brother, the Marquis Gold 5500/7000 does have an oil filter (arrow) that looks like a small automotive filter. It is accessed through a hole in the bottom of the generator compartment. Both the replacement filter and handy wrench are available through Cummins Onan dealers.|
|5) The Marquis Gold 5500/7000 has its spark plugs oriented on the sides of the cylinders (arrow), which can make them a challenge to reach. A swivel socket does the trick here. Removing the left (or Number 1) cylinder spark plug requires the removal of the air-filter assembly first.|
|6) Depending on the year and model, the 5500/7000 gas generators may actually have two fuel filters: this secondary one, near the carburetor, and a primary one at the fuel pump. Be sure to inspect your particular generator to see if it has two; replacing one won’t do it.|
1) The popular Honda EU2000i portable generator is not only reliable but easy to service. Popping off the front cover reveals the air-filter housing (A), carburetor (B) and oil fill/dipstick.
2) Removing the single screw reveals the main filter (C), which is made from a higher density foam, and the low-density foam pre-filter (D). Both are washable with a mild detergent and can be reused. The manufacturer recommends that these filters be oiled to help trap dirt,
|3) The Honda EU2000i has another small panel underneath the carry handle, which allows access to its single spark plug. Remove the boot and the plug like any other engine. The plug should be relatively clean and gapped to .025 inch.|
4) Changing the Honda’s oil isn’t difficult, but it can be messy — that’s why Smith Powerhouse offers this handy trick. Bend a piece of common cardboard into a trough and wedge it underneath the filler. Then you can tip the oil out of the crankcase and into a pan without it running into/onto the generator.
5) Cardboard is also employed during refill. Why not a funnel? Because the crankcase holds less than half a quart of oil, and since a funnel makes it difficult to see the level, it’s easy to overfill and make a mess. Pouring the oil in using this method allows you to clearly see when the oil is nearing its recommended level. The EU2000i does not use an oil filter.
6) Smith Powerhouse load tests all the portable units it services, too. Here you can see the EU2000i is putting out 122.2 volts, which is right in spec.
7) If you won’t be able to run the EU2000i for a while, it is easy to drain the fuel from the carburetor by turning this small screw underneath the float bowl counterclockwise. Fuel drains down the tube to the left and out the bottom of the generator. Put fuel stabilizer in the tank, keep the unit indoors, and you should be good for the off-season.