One of the great things about RVing is the way it allows you to enjoy most of the comforts of home anywhere you travel. Whether you’re camping for weeks in the middle of the Mojave or merely hosting a tailgate party at the stadium before kickoff, an RV allows you to have fun in supreme comfort and convenience.
When it comes to providing RV amenities just about anywhere, nothing beats having AC power on board, and when it comes to providing plenty of AC power, nothing beats a generator. But generators can be temperamental creatures, requiring attention every once in a while. For this reason, proper maintenance is essential.
Exercise Your Genset
Generators perform best when they’re “exercised” on a monthly basis. Long periods of inactivity, on the other hand, can result in serious damage. For starters, fuel that’s allowed to sit in an unused carburetor or injector may degrade in just a few months, producing varnish that clogs small fuel passages and prevents float valves from moving smoothly. Second, throttle linkages tend to get sticky when they aren’t operated over their entire range, resulting in poor engine-speed regulation and erratic operation under varying loads. Finally, oxidation may form on the alternator’s copper rotor-brush contacts after long periods of inactivity, causing voltage spikes or no AC output.
Here’s a suggested exercise regimen. After checking the oil and coolant levels, start the engine and allow it to run for a few minutes with no load connected. Next, connect a constant AC load to the output. This load should be large enough to represent a significant fraction of the generator’s maximum rated output—that is, several thousand watts for a 4-kilowatt genset. Small electric space heaters work well for this purpose.
Continue to operate the genset with this load for long enough—15-plus minutes—to allow the genset to come up to normal operating temperature. Disconnect and reconnect the load several times, listening to the engine speed to confirm that the governor returns the engine to the same speed each time. Finally, remove the load and allow the engine to run for a few minutes unloaded before shutting it down.
If your RV spends long periods in storage, you probably can’t exercise your gasoline-powered generator on a regular basis. In this case, it’s usually best to shut off the fuel supply while the generator’s running. This is typically accomplished by disconnecting the electric fuel pump. Allow the engine to run until it has consumed all the remaining fuel in the carburetor. This will help prevent problems that stem from old gasoline sitting in the carburetor. Because old oil can be corrosive on bearing surfaces, the oil and filter should also be changed before putting the RV into storage.
Some generator manufacturers recommend using aerosol cans of fogging oil, which can help prevent rust from forming on the piston rings and cylinder inside walls during long-term storage. Typically, the fogging oil is applied to non-diesel engines by removing the spark plugs and spraying the oil in the open spark-plug holes.
All About Oil Changes
When it comes to routine oil changes, the engine manufacturer’s recommendations should be observed. Although it may be tempting to increase the oil-change interval when using a premium synthetic oil, it’s usually best to stick with the manufacturer’s recommendations, at least until you can verify the oil’s integrity at extended change intervals with an oil-sample analysis.
Prior to installing a new oil filter, it’s usually a good idea to prefill the filter with fresh oil. This prevents the engine from running without oil pressure until the oil pump can fill the new filter. Most filters soak up a surprising amount of oil, so you’ll probably have to top off the filter several times before installing it.
The drain-plug location on some generators can make draining oil a messy experience. Fumoto Engineering
(www.fumotousa.com) makes a re-placement plug equipped with a built-in drain valve and hose-barb fitting. The valve allows you to drain the oil at the flip of a lever, and the hose barb ensures that the old oil ends up in your catch container rather than on the bottom of your generator compartment.
Complete tune-up kits are available for most RV generators. Typically, a kit consists of an air filter, an oil filter and spark plugs (for non-diesel engines) and sometimes a fuel filter.
Coaxing Consistent Power
Most modern generators are equipped with overhead valve engines, and some models require occasional adjustment of the valve lash. Typically, this task isn’t beyond the capabilities of any RVer who’s handy with a wrench. The valve cover is removed while the engine is still warm, the engine is rotated by hand to the manufacturer’s recommended position, and a feeler gauge is then used to measure the gap between the rocker arm and either the valve-stem tips or the pushrods. The gap is properly set with a small wrench and a screwdriver or hex wrench before replacing the valve cover, and you’re done.
Even though the current trend is toward electronic speed control, plenty of RV generators are still equipped with a mechanical governor. Typically, this mechanism consists of small engine-driven flywheel coupled to a lever that exerts a varying amount of force on the throttle linkage. As engine speed increases beyond the desired setting, the force exerted on the throttle decreases, thereby reducing engine speed. In this manner, engine speed is maintained at a constant value, typically either 3,600 or 1,800 RPM, regardless of how much electrical load is connected to the generator. Maintaining a constant engine speed ensures that the generator produces a constant 60-hertz AC output frequency.
Although the governor usually doesn’t require any maintenance other than occasionally oiling the throttle linkage, it may require readjustment to bring the generator’s output frequency back to 60 hertz. This can be accomplished by connecting a digital multimeter equipped with a frequency-measuring function to the generator’s AC output, adjusting the throttle linkage until the multimeter reads exactly 60 hertz.
In the absence of an appropriate multimeter, connecting an AC-powered mechanical clock, like an alarm clock, to the generator, can perform the adjustment. Compare the clock’s second hand with a wristwatch or stopwatch. When both clocks take exactly the same amount of time to sweep through 60 seconds, the generator produces pretty close to 60 hertz. If the AC-powered clock is reading slow, adjust the engine speed upward. If the clock reads fast, adjust the engine speed downward.
Gensets? You Bet!
The following RV generator manufacturers can help you enjoy the comforts of home wherever you roam.
Generac Power Systems
www.generac.com/RV
Honda Power Equipment
www.hondapowerequipment.com
Honeywell Generators
www.honeywellgenerators.com
Onan Corporation
www.onan.com
Yamaha Motor Corporation
www.yamaha-motor.com/generators