|
|
|
Here’s the scenario. You’ve invited about 40 guests to be at your home on a Saturday night for a pool party and just before the party starts a storm rolls through leaving you without power and some very agitated guests. Not to be outdone by the weather and the local power company, you run to the garage to get the generator you had just for this occasion. You’re prepared, or at least you thought you were. You turn the ignition switch on; you set the choke and pull the cord. It doesn’t start, so you pull the cord again. And again. And again. Still nothing. So you go back inside and explain to your guests that you think you flooded the engine and it won’t be long before you have the lights back on. Your brother-in-law offers to help, but he does the same thing you did, and again the generator won’t start. He inspects the air filter and tells you it must be the spark plug or something along those lines. It’s still dark in the house and your guests, by now frustrated, begin to leave one by one. Party foiled. |
|
Even though gasoline isn't the predominant fuel used in the larger back up generators, it is often used in smaller portable units and I want to help you avoid this potential social disaster. Hopefully I'll be able to offer some information concerning questions about "modern" gasoline and its effects on the internal combustion engine, your generator and ultimately your wallet. |
|
 Gasoline is an organic material and it begins to age and deteriorate the minute it leaves the refinery. By the time you put "fresh" fuel in your tank, it has already aged considerably. Gasoline continues to age as it sits in your tank. Basically, untreated gasoline has a 30-day shelf life.
|
|
You and your guests may age gracefully, but gasoline doesn't. During the aging process, masses of carbon, gum, and resin form in your gasoline. Fuels age because they become "chemically unstable". During transportation, storage and use, fuels are exposed to oxygen and heat. This exposure causes the atoms in the fuel to lose their balance (i.e. become unstable), molecular reactions take place, and the aging process begins. This happens to all fuels, especially today's reformulated "clean" fuels. |
|
Years ago, gasoline lasted up to a year, but not anymore. The reason for this is a bit complicated, but I’ll try to deduce it for you. Gasoline is no longer exposed to the atmosphere in automobiles due to the efficient manner in which gasoline is stored and used. Namely, fuel injection systems and vapor canisters keep gasoline relatively fresh, plus gasoline in your car is typically used up and replenished every week or two. For a carburetor to work effectively it needs to be exposed to the atmosphere via a small vent hole. The presence of this vent allows air to enter the fuel bowl, thus advancing the gasoline aging process considerably. |
|
Refineries aren’t focused on the moderately small use of carbureted engines currently in production, but on the major percentage of consumption. The modern automobile utilizes a sealed fuel injected system and therefore refineries don't distill gasoline with long-term storage in mind. Lead in gasoline was also an aging deterrent (though it was used as a knock retardant), but it hasn’t been in use since 1988. Basically, gasoline has changed, not for the worse, but for the better, considering how emissions have improved over the past 25-30 years. However, some things get left behind in the process. In this case it’s the carbureted engine. |
|
 Over the years, I have serviced many different types of generators including Portables, Home Standy, and Industrial Gensets. Repeatedly, the smaller gasoline powered generators come in with the complaint that the generator runs poorly or that it won't start at all. Diagnosis shows, in most of the cases, the Portable Generator has been stored with no fuel protection. As gasoline ages, gum and varnish-like deposits form within fuel system components, preventing gasoline from being able to flow through the carburetor and usually the carburetor is damaged from these deposits and must be replaced. Experience has proven an 85% failure rate in cleaning or rebuilding a gummed up carburetor. Worse yet, an attempt to start the engine on the bad gasoline results in sticking the valves in the engine. This malady is only caused by bad or aged gasoline. In most cases there is a pungent odor of stale fuel present. Incomplete burning of the gasoline leaving carbon deposits causes an odor of stale gasoline to still be present in the cylinder head after the engine is disassembled. A perfect indication that aged gasoline has been ingested.
|
|
So how do you combat this problem? Well, there are a couple of things you can do. One is to exercise the generator every two weeks to keep fresh gasoline in the carburetor. Another way is to drain the carburetor and fuel system, but this too can exacerbate the problem because each time the fuel is drained, a small residue of gas is left behind and this will cause problems, long term. Yet another way is to use gasoline that is already treated, but unless you’re a chemical engineer, this is difficult to know which oil company has the best additive and of course is minimal protection at best. The easiest and most useful way is to use an additive or preservative in the fuel. There are several products ranging from the " Mr. Clean of Gasoline" to nothing more than the proverbial “Mechanic in a Bottle”. Some products when added to gasoline not only stabilize the fuel but also reduce emissions and increase efficiency. Additionally, some have the capacity to recover aged gasoline to a volatile or combustible state. Do your research and decide what’s best for you and your application, or call GEN-TECH for a recommendation specific to your application. |
|
I trust this helped you understand the gasoline mystery that seems to plague many gasoline generator owners and hopefully your next social gathering will go off without a hitch. |
|
Michael Bonville
Power Generator Specialist
Training Administrator
Copyright © 2010 |