Generator Care Generator Maintenance

Why is My Generator Sputtering?

Generator sputtering happens quite often; it’s even common than you might think. If it does occur in your generator, you don’t have to be worried as much. At times, you will start the generator, run as usual, but it starts sputtering along the way. It might even start sputtering right after starting the engine and eventually dies. And right from there, your start worrying, asking yourself, why is my generator sputtering?

The main problem lies within the fuel system. It’s not solely about it, but it’s highly caused by it. It could be that your generator is running out of fuel or the carburetor is blocked and not allowing enough air in or reducing the gas flow. It could also mean there is an issue with the spark plugs.

As you can see, there is more than one cause of sputtering in generators. Let’s dive more into this problem to try and figure out why your generator is sputtering. Read along.

Why Does a Generator Sputter? (Troubleshooting and Fixing the Problem)

A sputtering generator has issues from starting failure, unexpected shutdown, sputters and stalls, or even rough idling.

If your generator is sputtering when you start it, it might be crying for help. It could be a sign that your generator isn’t getting enough gas. It might also be an issue with the fuel or the exhaust system caused by dirty or worn-out parts.

What might be the problem? Why does sputtering occur? Follow along as I break it down and help figure out why your generator is sputtering.

The problem in the Fuel System

One problem that may be causing your generator to sputter is an issue with the fuel system. That includes the fuel valve, fuel filter, and carburetor.

These critical components work together to make sure the fuel flows smoothly to the engine. The engine has to receive enough fuel, a mixture with air in the correct ratio to combust, and generator power.

And since these three components work together interconnected by the fuel line, if dirt and debris were to find a way in there, the problem could lead to more than simple clogging. That could lead to poor engine performance or even failure.

The best way to understand the part that is causing the problem is to check each item individually. Make sure you check your generator’s user manual to locate these parts.

Clogged Carburetor

The carburetor is mainly the cause of sputtering in generators, especially when clogged, but not always. The clogging is mainly caused when you leave fuel in the generator for more than two weeks without a stabilizer.

As time passes, the gas ingredients evaporate and leave behind a thick, sticker substance, which can clog the small air and fuel holes in the carburetor. Because of this, the generator starts to run rough.

Are you using the old gas? If you’re, that is the problem. Before you can clean the carburetor, you have to drain this fuel from your fuel tank and run fresh fuel through the carburetor.

Do you know how to drain the fuel? If not, here are some quick steps:

  • Take your generator to an open, ventilated place.
  • If you’re using an inverter generator, open the side panel to access the fuel line.
  • Close the fuel valve (use the user manual to locate it – mainly it’s located under the fuel tank)
  • Disconnect the fuel line from the carburetor and direct it to a bucket.
  • Open the fuel valve to allow the fuel to drain out from the fuel tank.
  • For some generators, you will need to remove an air filter connected to the carburetor.
  • Open the drain bolt from the bottom of the carburetor and drain everything out.

You’re done removing the bad/stale gas, but you still need to clean the carburetor with a carburetor cleaner. Try removing it and opening the interior to give a nice cleaning. Use the generator manual to locate the carburetor.

When cleaning the device, make sure you spray all the holes in it. If cleaning isn’t working, you can try rebuilding the entire carburetor. And if nothing is improving, replace the entire carburetor.

Clogged Fuel Filter

Old fuel can also cause clogging of a fuel filter or strainer. When the sticky substance is formed, it doesn’t cause issues in the carburetor alone. It might block the small filter holes that strain the debris and dirt from fuel.

You need to use your generator manual to locate the fuel filter or strainer, remove it and give it a nice clean. You can use a soft brush for a strainer or use the filter cleaner recommended by the manufacturer.

Clogged air filter

Clean air is an integral part of fuel combustion in the engine. When the air filters get clogged, there will be no enough air mixing with the fuel.

The fuel ratio has to be perfect for the correct combustion and displacement to occur. If that is hindered, it would mean the generator will not be initiating combustion while breaking, thus leading to sputtering.

The clogging can happen if you operate your generator in a dusty environment such as a construction site or a barn. But you can prevent the problem from reaching the sputtering level by cleaning them regularly.

It can be tempting to run a generator with an air filter. But you MUST never fall to the temptation as it might cause permanent damage to your generator engine.

Worn Out Spark Plugs

Sputtering in generators could also be caused by a worn-out or dirty spark plug. As a crucial part of the engine ignition, it needs to stay clean and in healthy condition. Else, the generator engine might not start, or it might start to sputter.

How does it work? The spark plug is designed to create a high-voltage spark during the engine’s compression phase to burn the air-gas fuel. When the terminals are dirty, that won’t happen. It’s the same case if they are worn out.

Remove the spark plug using the provided spark plug wrench or pliers to check for wear or damage. If there is a crack on the porcelain insulator or the electrode is burnt away or broken, replace it. If there’s carbon build-up at the electrode, clean it. But the carbon is not getting off; replace it.

You could also use a spark plug tester. If it tests strong or enough spark between the terminals, then it might be dirty. If it doesn’t get any spark, the spark plug is defective, and it’d be best to replace it.

Related Questions

Why does my generator keep dying?

The culprit is a fuel line problem, including the carburetor. If any of the parts in the fuel line get were clogged, especially the carburetor responsible for mixing the fuel with air, then the generator won’t start properly. It’s a common problem you’ll have to deal with if you leave gas fuel in the generator for too long. The stale gas can clog the carburetor preventing the engine from starting.

What causes a generator to backfire?

Backfiring in a generator occurs when unburnt fuel burns outside the burning chamber in a generator. It could be that your outlet valves are leaking, and they need to be checked. If left unchecked, it could cause damage to the engine and the exhaust.

Is Your Generator Sputtering? Here’s the Solution

As you have seen, the main culprits of generator sputtering are fuel line clogging, carburetor problems, air, and fuel clogging. Maintaining your generator correctly, cleaning the air and fuel filters regularly, and draining fuel during storage can help prevent the generator sputtering problem.

About the author

Sharif Gen

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