Why Is My Generator Sputtering? (Tips To Run Smoother)

When you are boondocking, the last thing you will need in this situation is to have your generator sputter. It is not a good feeling as your electrical systems depend on that power supply. Having the lights go out at the wrong time can mess up your meals.

One reason for the generator to sputter would be there is a problem with our carburetor. This part could have clogged fuel lines or there is a problem with the carb itself. A good cleaning additive will help you solve the problem and it may go away right after that cleaning.

To learn more about this problem just continue to read our article. It has the information you want to know about. The good news is that generally most of the solutions are easy and not that expensive.

Why is My Generator Sputtering While Running?


For older and some slightly used generators there are several problems that cause this problem. Most of these sources will not occur in new generators. To start off, the problem may be the carb itself.

This part can fail or be faulty and not mix the air or the fuel correctly. When that happens you get a sputtering action from the generator. The solution is to repair or replace the carburetor.

Another source will be you are using old fuel. When you leave fuel in the gas tank for long periods of time, some of the fuel will evaporate and when it does, it leaves the sticky elements behind.

These sticky elements clog the carburetor and keep the fuel from flowing smoothly. One suggestion to solve this problem is to put in a cleaning additive and let the generator run for a few hours. This additive can clean up the sticky elements and get the fuel flowing again.

Next on the list of sources will be a damaged spark plug. When your spark plug gets damaged it won’t ignite the fuel properly. The unburnt fuel will go through the system and cause the sputtering.

If the spark plug and carb are okay, then check the fuel filter. When it gets clogged it does not let enough fuel flow through the system. With a lack of fuel, the engine will sputter. The fix for this problem is to replace the fuel filter.

Stale fuel we have mentioned but it is worth mentioning again. Many RVers just leave the fuel inside the generator for months on end. This is not a good idea. The best thing to do is either run the generator till you use up the fuel in the tank or drain the fuel tank.

That way you can avoid the sticky element situation and protect your generator’s fuel system parts.

New Generator Sputtering


There are two main sources for this situation. One is not a nice feeling as it means you bought a bad generator and will have to take the time to get a replacement or your money back.

It does happen from time to time with all products including cars, trucks, RVs as well as generators. If you bought a lemon then expect it to have problems from the get-go. Sputtering will be o e of those problems.

The source could be as simple as the carb was set wrong and the air-fuel mixture is off to a bad carb, spark plug or some other part was defective but still installed in the generator.

The other main source for a new generator to sputter would be the type of fuel you put in its gas tank. This is not old fuel, and you should never use old fuel if you have some lying around. We are talking about the modern fuels that most gas stations and other gas suppliers have in their pumps.

Today's fuels are often made with ethanol, a combination of MTBE and alcohol, and this fuel could cause sputtering in a new generator. Ethanol has a very short shelf life and turns bad in a matter of weeks.

With alcohol being part water and ethanol being labeled as oxygenated you have two sources for this problem. It is the presence of water and the extra oxygen that breaks the fuel down and turns it into bad fuel that your generator can’t run on.

If you can avoid buying ethanol-related fuel, that would help your generator run better. Watch out for the biodiesel fuel as well as many of those fuels run on natural products like soy and these ingredients are not as good as real diesel.

The source of the bad fuel is usually the discount gas stations that save you a few cents on the gallon. Their fuel supply is supposed to be 30 days old when they buy it so you are not getting the best fuel possible.

Generator Sputtering Under Load


If you have checked all of the above, turn your attention to the air filter. If it is dirty, then the air won’t flow through the filter and get mixed with the gas. If it is dirty, then change the filter, and hopefully, that will solve your sputtering problem.

Another source we have not talked about, and the previous sources will apply to this situation as well, is the governor spring. If it has been disconnected, it will cause the sputtering when you are under load.

Just reconnect the spring or see if it needs to be replaced. If you have a dual-fuel generator, the fuel selector switch may be bad and you are getting a mixture of fuels through the system.

Or the float in the carb is malfunctioning. These parts would have to be replaced as there are no real fixes for either one. Also, check the previously mentioned possible sources as those would contribute to this problem.

There is one simple source that has not been discussed yet and it does not cost anything to fix. Many generators come with an altitude screw and if it is adjusted wrong, it can cause the sputtering when the generator is under load.

All you have to do is check your altitude and then see where the screw is set to. If you are at sea level, then it should be set to sea level. If you are 5000 feet above sea level, then the screw needs to be set for that altitude.

A simple screwdriver should be all that you need to make the adjustment. Then run the generator unloaded till it is warmed up. At that point place as much load on the generator as possible.

You should hear a hiccup and then the generator should run smoothly. The screw is in plain sight and marked with different elevations on some models. Others may just have hash marks to guide them.

The Generator Not Running Smoothly


All the issues that we have already mentioned in this article apply to this problem. Yet, there is still one more to add to the list. This new source is also easy to fix and does not cost you anything to make the adjustment.

Your generator may be overloaded. This happens a lot with many RVers. They forget that the generator only puts out so much power and plug in too many electrical devices.

The fix is to unplug some of those electrical devices. The way to avoid this problem is to figure out how much power you will need when you are on your trip, and then go out and buy a generator that supplies more electricity than that amount of demand.

You only have to go 1.5 times your power demand when you buy the bigger generator.

How Can I Make My Generator Run Smoother?


Here are some tips to help you avoid the rough running and sputtering problem:

1. Run your generator at least once a month to prevent the fuel from going stale

2. If this is not possible, then add a fuel stabilizer to your fuel supply. Run the generator for 10 minutes to thoroughly mix the stabilizer with the fuel

3. Make sure all fuel valves are at the right setting

4. Make sure all levers and the choke are always in the right position

5. Do not plug in more electrical devices than the generator can handle. Supply is limited so do some calculations and remember that start up power has higher electrical demands than running time does.

6. Check the air and fuel filters to make sure they are clean. Also, check the carb and the spark plug to make sure they are not damaged or clogged. Do regular maintenance cleanup as well

Some Final Words

A sputtering generator is not a major problem. It may just mean that you have not done any maintenance to the fuel system or you let the gas get stale. No matter the issue, the fixes are inexpensive and most can be done by you if your generator is not under warranty. Don’t forget to check your altitude either.

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