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RV Doctor ColumnRV Doctor #307 Dear RV Doctor, we have a 1999 Winnebago, Journey. We have 150 hours on our Onan generator. It will only run if sprayed with WD-40 and then for just a couple of minutes and then dies. Any suggestions? We changed the filters. Does this sound like a carburetor problem? Jan Carbone, (Temecula, CA) Jan, it's quite possible a generator with 150 hours on it may need cleaning and adjusting. Of course a lot depends on how hard it has been run in the past; at what altitude and in what climatic environments. It may be time to replace some components. It may be something as simple as sticking mechanical linkages since it seems to run better when you apply some WD-40. At the very least, it's probably time to have the generator properly set up. There are three possible adjustable components on the typical RV generator and each component has multiple adjustments. Periodically, each of these adjustment points must be checked and set properly. The choke assembly may have one or two adjustments, the governor will have a couple and the typical gasoline carburetor will have three adjustments. Here's the drawback - each adjustment to the carburetor and the governor has a direct electrical result. In other words, every time someone turns a screwdriver or a wrench on those two components specifically, the voltage and the electrical frequency will change. The only way to correctly adjust the carburetor and the governor is by monitoring the output voltage and frequency at the same time a specific load is applied. That's why it's impossible to "tune a generator by ear" like we used to do with lawnmowers and other small gasoline engines. Many handypersons (and some service technicians) have a habit of trying to adjust the RV generator to make it "run right." Unfortunately, this only results in a poor running machine and/or incorrect output voltage, etc. There are a strict set of procedures whereby a generator is properly set up using a device called a load bank. Only qualified RV technicians should attempt to tune a generator. If your local RV center is not familiar with generator tune-ups, we have produced a professional technical training videotape detailing those exact procedures. If you or your shop is interesting in obtaining the tape, simply send us your mailing address and we'll send you the ordering instructions. Wish I had an easy fix for you, but measurements must be taken and the generator adjusted correctly before diagnostics can continue. Dear Gary, I dropped a plastic flashlight into the toilet and it went straight down the pipe to where I could not see it. The reason I was using a flashlight was to determine what might be causing a backup in my black water holding tank. Now I apparently have two problems. I can backflush the tank with the attachment on the drain and also force water down the toilet from that end to eventually get things cleaned out. The pipes are all glued and therefore not easily removed to get to the possible plug. Do you have any ideas how I might be able to extricate a plastic flashlight which is probably lodged in a 45 degree turn going into the black water tank? Sherman Thompson, (Logan, UT) Sherman, I'm guessing the drop of the flashlight went straight into the tank itself. Most configurations have the toilet positioned directly over the tank with a straight pipe into it. There are a few floor plans which mandate an elbow turn, but unless that was one big, honkin' flashlight, it still probably entered the tank. The good news is that all holding tanks must be removable. Though drain pipes may be cemented, the assembly can easily be cut apart if necessary. The termination valves are usually bolted so it may be possible to simply unbolt the valve assembly, remove the toilet and flange from above, then remove the attaching brackets to drop the tank. Obviously it's best to flush the tank as good as possible first. Once the tank is down, you should be able to manipulate the flashlight to the three-inch outlet opening and retrieve it. Though a hassle and not very pleasant a task, it is doable and not that bad a situation. Once dropped, you can then, more easily, inspect the tank to determine the cause of the first blockage. Oh, and be sure to change those batteries! Dear RV Doctor, how hot does the boiler on the back of a refrigerator get. We have a propane/electric refrigerator in our camper. This past weekend, we tried to use the fridge on electric power and noticed that it was not cooling like it should have. A metal box on the back of the fridge was hot to the touch. It almost seemed too hot! The ambient temp outside was 95 degrees plus. Any advice is appreciated. Rod Goins, (Rapid City, SD) Rod, the rear components of any absorption refrigerator will get extremely hot. That's why leveling and correct venting of that heated air is so crucial to the proper operation of the unit. Cleanliness also plays a part in the overall effectiveness of operation as well. Over 95 degrees ambient temperatures will put a huge load on any absorption unit to transfer the heat from inside the box. It's probably not realistic to expect inside temperatures to sink much lower than about 30 degrees below ambient in such conditions. Plus the heat buildup out back will be amplified as well adding to the detriment. The boiler section of the cooling unit will always be the hottest under normal situations since that is where the heating element and LP burner are located. Blocked cooling units will experience hotter than normal temperatures at the absorber vessel and along the absorber coils as well, but typically the entire rear of the refrigerator will get quite warm. As long as you are level and there is a clear chimney effect behind the refrigerator, there's not much that can be done until the ambient temperature drops some. The addition of an auxiliary exhaust fan will help if you continue to experience such high temperatures. Also an internal fan inside the refrigerator will be beneficial. Try not to open the door to peruse the contents like I do when I'm searching for a quick snack. Open the door, remove the object and close it right away. There could be a thermostat issue at work here also, but not enough information is provided to delve into that. Chances are, the high ambient temperature is the cause of the seemingly inefficient operation of the refrigerator.
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